jimrandomh

LessWrong developer, rationalist since the Overcoming Bias days. Connoisseur of jargon.

jimrandomh's Comments

How to convince Y that X has committed a murder with >0.999999 probability?

If I sometimes write down a 6-nines confidence number because I'm sleepy, then this affects your posterior probability after hearing that I wrote down a 6-nines confidence number, but doesn't reduce the validity of 6-nines confidence numbers that I write down when I'm alert. The 6-nines confidence number is inside an argument, while your posterior is outside the argument.

How to convince Y that X has committed a murder with >0.999999 probability?

Six nines of reliability sounds like a lot, and it's more than is usually achieved in criminal cases, but it's hardly insurmountable. You just need to be confident enough that, given one million similar cases, you would make only one mistake. A combination of recorded video and DNA evidence, with reasonably good validation of the video chain of custody and of the DNA evidence-processing lab's procedures, would probably clear this bar.

Why don't we tape surgical masks to the face to seal them airtight?

As a diabetic, I have a few things (insulin infusion canula, continuous glucose monitor) that attach to skin with adhesive. In principle, you could use medical tape around the edges of a normal mask, and it would improve the seal. I think the reason people don't do this is because it's a lot of effort to put on (effort which could be spent improving the fit in other ways), and it's physically painful to take off. This limits its usefulness to the range where an imperfectly-fitted N95 isn't good enough, but a positive-pressure suite isn't necessary; I'm not sure situations in that range are at all common.

Will COVID-19 survivors suffer lasting disability at a high rate?

Responding to this news article which is responding to Bornstein et al on the subject of diabetes as a complication of COVID-19 infection.

The paper is primarily about management of COVID19 in patients with existing diabetes, rather than the risk of new-onset diabetes as a result of COVID infection, so it's on shakier ground than you might expect given the news article. The relevant arguments given are: (1) pancreatic beta cells express ACE2 in a mouse model, (2) SARS1 was known to directly damage pancreatic beta cells, and (3) Italian physicians anecdotally report a high rate of DKA in new-onset COVID19 patients (no percentage or citation).

This is strong enough to convince me that this is a thing that happens, for at least a non-negligible (but not necessarily large) subset of the patients who are admitted to ICU.

Some background for people less familiar with diabetes. Pancreatic beta cells produce insulin, which is a hormone that signals to the rest of the body that they should eat the sugar that's in the blood. Under normal circumstances, this keeps blood sugar within a narrow range (70-110mg/dL). However, if the pancreas is damaged or if the pancreatic-function-to-body-size ratio is too low, it can't produce enough insulin, so blood sugar rises higher than it's supposed to. Very high blood sugar is toxic to pancreatic beta cells themselves, causing a feedback loop which leads to a state called diabetic ketoacidosis (DKA), which is reliably fatal if left untreated.

For SARS1, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7088164/ says:

Twenty of the 39 followed-up patients were diabetic during hospitalization. After 3 years, only two of these patients had diabetes.

Unfortunately the paper didn't say how many of those patients had gotten as far as DKA, as opposed to developing diabetes short of DKA in a hospital setting and having it treated promptly. I haven't verified this yet, but my prior belief was that anyone who enters DKA is probably going to be diabetic forever.

This is all separate from the question of whether there's a lasting risk of diabetes in patients who were not hospitalized, or who survived their hospitalization without obvious blood sugar complications. This is a hard question; it seems plausible, but we don't yet have empirical evidence either way. My guess is probably some increased risk, but not a very large one, and decreasing over time.

The Chilling Effect of Confiscation

I have a suspicion that some of these seizures are not actually being done by the federal government, but actually are straightforward robberies where the thieves lie about their identity.

[Site Meta] Feature Update: More Tags! (Experimental)

Yes, I think That Alien Message should have the AI Alignment tag. (In general, if older posts don't have tags, it mostly means no one has considered yet whether the tag should be applied.)

Helping the kids post

These are adorable.

If she does decide to post to LessWrong, the reception will probably be better if it's an Open Thread comment or in the Shortform section, than if it's a top-level post.

COVID-19's Household Secondary Attack Rate Is Unknown

This is definitely an improvement over the US CDC and Shenzhen papers, but I still have reservations about it. The first issue is that it's based on calling people and asking about symptoms, not based on testing. So it doesn't count asymptomatic people, nor people with mild symptoms who don't disclose them. The second issue is that their numbers imply an average household size of 6.4, which implies a definition of "household" which is somehow not as expected.

They track contacts of the first 30 identified cases of COVID-19 in South Korea, and find 119 household contacts, of which 9 are infected. Table 2 describes every transmission they found, and whether it was a household transmission. Of the first 30 cases, 8 of them got it by household transmission from someone else who was also one of the first 30 cases, so that's 22 distinct households.

(30 people + (119 contacts - 8 already counted)) / 22 households = 141/22 = 6.4 people per household.

Jimrandomh's Shortform

Genetic engineering is ruled out, but gain-of-function research isn't.

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