Comparison of viral levels in individuals with or without symptoms at time of COVID-19 testing among 32,480 residents and staff of nursing homes and assisted living facilities in Massachusetts. | medRxiv
In aggregate, the distributions of Cts for viral probes used in the qRT-PCR assay were very similar, with a statistically but not meaningfully different mean (?Ct 0.71 cycles, p = 0.006) and a similar range (12-38 cycles), between populations with and without symptoms over the entire time period, across all sub-categories examined (age, race, ethnicity, sex, resident/staff).Viral load is comparable between COVID-19 victims who are asymptomatic and symptomatic.
Although SARS-CoV-2 RNA shedding in respiratory and stool can be prolonged, duration of viable virus is relatively short-lived. Thus, detection of viral RNA cannot be used to infer infectiousness. High SARS-CoV-2 titres are detectable in the first week of illness with an early peak observed at symptom onset to day 5 of illness.…also backs up that infectiousness starts around 2 days prior to symptom onset.
Arrow combines the benefits of columnar data structures with in-memory computing. It provides the performance benefits of these modern techniques while also providing the flexibility of complex data and dynamic schemas. And it does all of this in an open source and standardized way.(via Tony Finch)
Ugh — PKI expiry lifetimes were such an awful idea.
As of writing, a large number of Samsung Blu-Ray players around the world are stuck in a reboot loop. Although customers are still waiting for the official word on the issue, the suspicion is that the problem is caused by an expired certificate that stops the device firmware from booting properly, possibly because of strict digital rights management requirements that require verification and signing before full start-up of the players. As Scott points out, there are hundreds of ageing Root CAs out there, many more when you include the intermediates. Over the next few years, more will expire.(via Tony Finch)