Hopefully Interesting

 New sooner have I posted about the Coronavirus then a couple of new things come up. Yesterday I came across a really great paper,  Beyond Six Feet: A Guideline to Limit Indoor Airborne Transmission of COVID-19 .  It's related to a tool for figuring out risks of indoor aerosol transmission but the information in that paper was what was really interesting to me.  I'd thought that aerosols were only generated by our lungs' alveoli but apparently they can be generated by vocal cords too when you use them to speak, sing, etc.  I suppose the bit I had read earlier was making the simplifying assumption that people are silently sitting still or something.  Anyways, I'd been really interested in how much of what size of aerosol or droplet was generated by what sort of vocalization and what should this paper have but the graph I'd always wanted.     I'd previously been told that 2.5 micron aerosols are most common which looks to be  approximately true for nose breathing

I've fallen a bit out of the habit of blogging so I figured I'd do something fairly easy to start to get back in the habit.  Over the course of the pandemic I've been learning a lot about virology.  Most of this is, as far as I can tell, very basic stuff from the perspective of a virologist but it was surprising to me and might also be new to you who are reading this. Viral Load First of all, viral load is important.  I'd normally thought of people as either sick with a virus or not sick previously.  The easiest way to look at this is from the tools we use to detect viruses.  The way a PCR machine works is that you double the amount of viral RNA in a sample again and again and eventually you have enough virus to detect it by macroscopic means.  The number of times you have to double the amount of RNA before it becomes detectable is called the cyclic threshold or CT value.  For a sensitive PCR machine you can detect RNA down to a CT of 37 to 40.  And the highest viral lo