Post #1027: A correction on my William and Mary calculation

Same story as before, just a different baseline.  The upshot is that the red line — the expected count of new COVID-19 cases — should be based on 70% of total student enrollment.

And as a result of that correction, W&M’s COVID-19 incidence is not much different from what you would expect, based on the community rate.  But it’s not (yet) better than you would expect.  At the current rate, it’s going to take another week or two to get there.

Details follow. Continue reading Post #1027: A correction on my William and Mary calculation

Post #1024: I just got my first smart phone, and I’m beginning to understand what’s wrong with America.

Sometimes there is value in being an outsider.

I’ve just gotten my first smart phone.  I guess I’m only a decade and a half late to the party.

But as a result of my tardiness, I am now deeply weirded out by things that I assume all Americans now simply take for granted. Continue reading Post #1024: I just got my first smart phone, and I’m beginning to understand what’s wrong with America.

Post #1023: Next N95 mask purchase

Currently, I’m wearing the Kimberly-Clark N95 duckbill, on sale at Amazon for $52 for a bag of 50.  This was my choice for an N95 mask purchase, for several reasons:

  • Solid evidence that these are genuine (read the Amazon comments).
  • Reputable US manufacturer (Kimberly-Clark)
  • Reputable seller (Amazon), available from other reputable vendors.
  • Industrial mask not suitable for hospital use (NIOSH-certified but not FDA-certified)
  • Cheap, at $1/mask.

When you add all that up, what that mostly means is that there’s not a lot of profit in trying to counterfeit these.  Continue reading Post #1023: Next N95 mask purchase

Post #1020: PriUPS

This post is prompted by a recent article on Texans using their hybrid vehicles as electrical generators.  This being Texas, of course the vehicle in question is a pickup truck, in particular, the Ford F150 hybrid pickup.

And so, in 2021, Texan F150 hybrid owners are finding out what Prius owners have known since at least 2005:  A hybrid car makes an excellent backup generator.  In this post, I’ll lay out the simplest approach to using your Prius (or similar full hybrid) as an emergency generator. Continue reading Post #1020: PriUPS

Post #1013: Thirty percent of new Virginia COVID-19 cases are “probable” cases.

Source:  Calculated from Virginia Department of Health data, available at this URL.

Virginia’s COVID-19 case count includes both confirmed and probable cases.  And that’s a good thing, because the technology of testing has changed over the course of the pandemic.
Continue reading Post #1013: Thirty percent of new Virginia COVID-19 cases are “probable” cases.

Post #955: More people saying “get a better mask”.

This might be a case of finding what I’m looking for.   But I seem to be seeing more mentions in minstream media regarding the need to wear N95 masks (respirators).  In particular, I see more people pointing to citizen use of N95s as a rational response to the new, more contagious British variant of COVID-19.

In mid-2020, a policy of reserving N95s for health care workers made sense.  But now that domestic production has increased several-fold, and even a hard-hit state like Minnesota has a half-year supply on hand for hospital use (see below), and we’re facing a faster-spreading COVID variant, it’s more than time to rethink that, and start getting N95s into the hands of the public.

Continue reading Post #955: More people saying “get a better mask”.

Post #929: An odd footnote on the post-Thanksgiving surge that never happened

Source:  Plotted from data from the NY Times Github COVID data repository.  Data reported through 12/26/2020

Edit:  You can now see this clearly, with 20-20 hindsight, in (e.g.) Post #941.  The holidays do, in fact, put a significant dip in the reported infection count.

Holidays introduce several types of artifacts in the data on new COVID-19 cases.

There’s an immediate “reporting” artifact.  Many public health departments are short-staffed on the holiday, and they aren’t able to tabulate all the new COVID-19 test results that arrive on the holiday itself.  That creates a sharp one-day dip-and-rebound in reported rates.  We saw that at Thanksgiving, predicted in Post #901, confirmed just post-Thanksgiving in Post #909).  And, as above, we’ve now seen that same pattern for Christmas day.

There are other artifacts, but they will be more subtle than that, and harder to spot.  Presumably, there’s a slowdown in the actual rate of testing (because who goes out on Thanksgiving to get a COVID-19 test), and that shows up as a dip in the rates a few days later.  Finally, there’s the actual “surge” — if any — the actual increase in infections due to holiday travel and such, that shows up anywhere from 12 days to three weeks after-the-fact.

This post is about an odd discovery that I made when try to smooth out the Christmas reporting artifact, shown above.  The discovery is that there isn’t a simple offsetting dip-and-rebound in the reported rates.  The rebound isn’t as big as the dip.  There’s actually a small, permanent one-off reduction in the number of positive cases found, associated with that holiday day.  True for Christmas.  And, in hindsight, true for Thanksgiving as well.

It’s as if some people who would have tested positive just never bother to get tested.  Presumably, because of the holiday.  And never get tested afterwards, to make up for it.  Presumably because, eh, they probably don’t have a very bad case of COVID-19.  And so, apparently, just deal with their COVID infection.

This is no more than an odd footnote.  My real goal here was to talk about trends.  But, in fact, I just have to let the Christmas data glitches work their way through the system before I can talk about trends again.

A small amount of detail follows. Continue reading Post #929: An odd footnote on the post-Thanksgiving surge that never happened

Post #927: Wheelchair floor-to-chair aid, V3

The brief for this task:  Create a floor-to-chair aid for wheelchair users.  It must be able to be made at home, using only simple hand tools and readily available materials.

The end result is shown directly below.

Above:  Floor-to-chair aid, folded and covered.  For scale, the push-up bars sitting on top are 6″ tall.

Above:  Rear view, folded.  Lower stairs sit atop upper stairs when folded.  The boxes nearest the camera flip away from the camera when put into use.

Above:  Rear view, unfolded.  Lower stairs have been flipped off the top, away from camera, revealing hardboard stair tops.  Push-up bars are on top.

Above:  Front view, folded.  Blue cloth connects the lower and upper sections of the staircase.

Above:  Front view, unfolded.  Lower stairs have been flipped off the top, toward the camera, revealing hardboard stair tops.  The blue cloth keeps the upper and lower stairs connected. Continue reading Post #927: Wheelchair floor-to-chair aid, V3

Post #926: Knife guide for cutting corrugated cardboard.

This post is a set of instructions for creating a utility knife guide, for making fast, straight, precise cuts in corrugated cardboard, using a utility knife.  This guide only cuts cardboard to 4″ widths, but you can easily modify it for other widths.  It uses about $7 in parts, and takes about 15 minutes to construct. Continue reading Post #926: Knife guide for cutting corrugated cardboard.