RNA-Seq Updated +Created
Sequencing the DNA tells us what the organism can do. Sequencing the RNA tells us what the organism is actually doing at a given point in time. The problem is not killing the cell while doing that. Is it possible to just take a chunk of the cell to sequence without killing it maybe?
Delft University of Technology Updated +Created
Eigendecomposition of a real symmetric matrix Updated +Created
The general result from eigendecomposition of a matrix:
becomes:
where is an orthogonal matrix, and therefore has .
Electric charge Updated +Created
LibreTexts Updated +Created
Follows the "certified teacher only" approach which is in Ciro Santilli's opinion a fatal flaw of most elearning systems out there, OurBigBook.com won't suffer from that!
But that is a very, very good project.
All notes appear to have been extracted from existing notes, as noted on the bottom of each page.
TODO how does it work exactly? Do they ask for permission from authors in every case, including when the content has open license? Or when it has open license, do they just do it? In some cases, the notes have no license, so they must have asked.
TODO what is the source code that authors write? LaTeX or something else? LaTeX feels extremely likely given that it is what most original materials were already written in.
They are attempting a "model up this entire university" thing: phys.libretexts.org/Courses which is good. E.g. they have a bunch of "quantum mechanics ones under: phys.libretexts.org/Bookshelves/Quantum_Mechanics
Appears to be UC Davies-based mostly.
They claim to use this closed source backend: www.nice.com/resources/cxone-expert-knowledge-management? Seriously? For a publicly funded project with low-tech requirements?? It is mind blowing.
Some issues:
OK let's database it:
Logic gate Updated +Created
Ohm Updated +Created
Phonetics Updated +Created
Teach For All Updated +Created
Ubuntu 18.04 Updated +Created
Ubuntu 23.10 Updated +Created
CIA 2010 covert communication websites / 2013 DNS census MX records Updated +Created
Let' see if there's anything in records/mx.xz.
mx.csv is 21GB.
They do have " in the files to escape commas so:
mx.py
import csv
import sys
writer = csv.writer(sys.stdout)
with open('mx.csv', 'r') as f:
    reader = csv.reader(f)
    for row in reader:
        writer.writerow([row[0], row[3]])
Would have been better with csvkit: stackoverflow.com/questions/36287982/bash-parse-csv-with-quotes-commas-and-newlines
then:
# uniq not amazing as there are often two or three slightly different records repeated on multiple timestamps, but down to 11 GB
python3 mx.py | uniq > mx-uniq.csv
sqlite3 mx.sqlite 'create table t(d text, m text)'
# 13 GB
time sqlite3 mx.sqlite ".import --csv --skip 1 'mx-uniq.csv' t"

# 41 GB
time sqlite3 mx.sqlite 'create index td on t(d)'
time sqlite3 mx.sqlite 'create index tm on t(m)'
time sqlite3 mx.sqlite 'create index tdm on t(d, m)'

# Remove dupes.
# Rows: 150m
time sqlite3 mx.sqlite <<EOF
delete from t
where rowid not in (
  select min(rowid)
  from t
  group by d, m
)
EOF

# 15 GB
time sqlite3 mx.sqlite vacuum
Let's see what the hits use:
awk -F, 'NR>1{ print $2 }' ../media/cia-2010-covert-communication-websites/hits.csv | xargs -I{} sqlite3 mx.sqlite "select distinct * from t where d = '{}'"
At around 267 total hits, only 84 have MX records, and from those that do, almost all of them have exactly:
smtp.secureserver.net
mailstore1.secureserver.net
with only three exceptions:
dailynewsandsports.com|dailynewsandsports.com
inews-today.com|mail.inews-today.com
just-kidding-news.com|just-kidding-news.com
We need to count out of the totals!
sqlite3 mx.sqlite "select count(*) from t where m = 'mailstore1.secureserver.net'"
which gives, ~18M, so nope, it is too much by itself...
Let's try to use that to reduce av.sqlite from 2013 DNS Census virtual host cleanup a bit further:
time sqlite3 mx.sqlite '.mode csv' "attach 'aiddcu.sqlite' as 'av'" '.load ./ip' "select ipi2s(av.t.i), av.t.d from av.t inner join t as mx on av.t.d = mx.d and mx.m = 'mailstore1.secureserver.net' order by av.t.i asc" > avm.csv
where avm stands for av with mx pruning. This leaves us with only ~500k entries left. With one more figerprint we could do a Wayback Machine CDX scanning scan.
Let's check that we still have most our hits in there:
grep -f <(awk -F, 'NR>1{print $2}' /home/ciro/bak/git/media/cia-2010-covert-communication-websites/hits.csv) avm.csv
At 267 hits we got 81, so all are still present.
secureserver is a hosting provider, we can see their blank page e.g. at: web.archive.org/web/20110128152204/http://emmano.com/. security.stackexchange.com/questions/12610/why-did-secureserver-net-godaddy-access-my-gmail-account/12616#12616 comments:
secureserver.net is the name GoDaddy use as the reverse DNS for IP addresses used for dedicated/virtual server hosting
Eigenvalue Updated +Created
g4nd.xlarge Updated +Created
TODO meaning of "nd"? "n" presumably means Nvidia, but what is the "d"? Compare it g4ad.xlarge which has AMD GPUs. aws.amazon.com/ec2/instance-types/g4/ mentions:
G4 instances are available with a choice of NVIDIA GPUs (G4dn) or AMD GPUs (G4ad).
Price:
GitHub book repo Updated +Created
Some amazing people have put book source codes on GitHub. This is a list of such repos.
Implicit metric signature in Einstein notation Updated +Created
Then a specific metric is involved, sometimes we want to automatically add it to products.
E.g., in a context considering the common Minkowski inner product matrix where the 4x4 matrix and is a vector in
which leads to the change of sign of some terms.
Knol Updated +Created
Very similar to OurBigBook.com!
People who worked on it:
Video 1.
How to use Google Knol by Hack Learning (2011)
Source. One of the last users of the website for sure! The owner of that YouTube channel is a Mark Barnes:
Video 2. Source.
Replying to a listener phone-in question WNYC radio, mediated by Brian Lehrer.
It was about to launch it seems, and it was not clear at the time that anyone could write content, as opposed to only selected people.
Jimmy then corrects that misinformation. He then clearly states that since there can be multiple versions of each article, including opinion pieces, like OurBigBook.com, Knol would be very different to Wikipedia, more like blogging than encyclopedia.
Video 3.
Google Knol: the future of academic journals? by Doug Belshaw (2010)
Source.
Bibliography:
List of AWS AMIs Updated +Created
Kudos Updated +Created
Ahh, Ciro Santilli was certain this was some slang neologism, but it is actually Greek! So funny. Introduced into English in the 19th century according to: www.merriam-webster.com/dictionary/kudo.

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