Ciro Santilli @cirosantilli 37

You can then measure the DNA concentration based on simple light refraction methods to see if there is a lot of DNA or not in the post-processed sample.

Even Ciro Santilli had some contact with it at: Section "How to use an Oxford Nanopore MinION to extract DNA from river water and determine which bacteria live in it", see: PCR!

One common problem that happens with PCR if you don't design your primers right is: en.wikipedia.org/wiki/Primer_dimer

Sometime it fails: www.reddit.com/r/molecularbiology/comments/1kouomw/when_your_pcr_fails_again_and_you_start/

Nothing humbles you faster than a bandless gel. One minute you’re a scientist, the next you’re just a pipette-wielding wizard casting spells that don’t work. Meanwhile, physicists are out there acting like gravity always behaves. Smash that upvote if your reagents have ever gaslit you.

and a comment:

PCR = Pray, Cry, Repeat

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Ciro's Edict #8 / Advances Updated 2025-07-16

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Nightmare Updated 2025-07-16

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Polynomial over a field Updated 2025-07-16

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By default, we think of polynomials over the real numbers or complex numbers.

However, a polynomial can be defined over any other field just as well, the most notable example being that of a polynomial over a finite field.

For example, given the finite field of order 9,

GP (3)

and with elements

{0, 1, 2}

, we can denote polynomials over that ring as

GP (3) [x]

(1)

where

x

is the variable name.

For example, one such polynomial could be:

P (x) = 2 x^{4} + x^{2} + 2

(2)

and another one:

Q (X) = x^{3} + 2 x^{2} + 2

(3)

Note how all the coefficients are members of the finite field we chose.

Given this, we could evaluate the polynomial for any element of the field, e.g.:

P (0) = 2 (0 \times 0 \times 0 \times 0) + (0 \times 0) + 2 = 2 P (1) = 2 (1 \times 1 \times 1 \times 1) + (1 \times 1) + 2 = 2 (1) + 1 + 2 = 2 P (2) = 2 (2 \times 2 \times 2 \times 2) + (2 \times 2) + 2 = 2 (16

(4)

and so on.

We can also add polynomials as usual over the field:

P (x) + Q (x) = 2 x^{4} + x^{3} + (1 + 2) x^{2} + (2 + 2) = 2 x^{4} + x^{3} + (0) x^{2} + 1 = 2 x^{4} + x^{3} + 1

(5)

and multiplication works analogously.

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Wiki Updated 2025-07-16

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Rich person Updated 2025-07-16

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Werner Heisenberg Updated 2025-07-16

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Participated in the German nuclear weapons program, ouch.

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String polarization Updated 2025-07-16

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This is about the polarization of a string in 3D space. That is the first concept of polarization you must have in mind!

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Hayflick limit Updated 2025-07-16

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PostgreSQL GIST Updated 2025-07-16

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www.postgresql.org/docs/15/gist.html
www.postgresql.org/docs/15/datatype-geometric.html
medium.com/postgres-professional/indexes-in-postgresql-5-gist-86e19781b5db the only example on the net!

The highly underdocumented built-in module, that supports SQL spatial index and a lot more.

Quite horrendous as it only seems to work on geometric types and not existing columns. But why.

And it uses custom operatores, where standard operators would have been just fine for points...

Minimal runnable example with points:

set -x
time psql -c 'drop table if exists t'
time psql -c 'create table t(p point)'
time psql -c "insert into t select (point ('(' || generate_series || ',' || generate_series || ')')) from generate_series(1, 10000000)"
time psql -c 'create index on t using gist(p)'
time psql -c "select count(*) from t where p <@ box '(1000000,1000000),(9000000,2000000)'"

The index creation unfortunately took 100s, so it will not scale to 1B points very well whic his a shame.

Some sources about it:

stackoverflow.com/questions/28292198/how-to-port-simple-spatial-index-using-sqlite-r-trees-to-postgres

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Frequency Updated 2025-07-16

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