/sci/ - Science & Math

Does anybody here know dick about group cohomology?

About the definition as a derived functor: if G is a group and A a ZG module (ZG = integral group ring) apparently group cohomology are the derived functors of passing from A to the submodule of G-invariants of A.

So to get group cohomology shouldn't we take a resolution of A, switch over to G-invariants (i.e. apply our functor to the resolution) and then compute homology of our new chain complex?

Because in the wiki-article (in the paragraph about ext) we take a resolution of Z, not A, and then apply hom(-,A) to some projective resolution of Z in the category of ZG modules (with Z as a trivial ZG module).

Now apparently hom(Z,A) (in the category of ZG modules) is isomorphic to the submodule of G-invariant elements of A, but that's all the connection I could find.

So can somebody shed some light on this?

Hey /sci/

My beard is a hassle. I have had excess keratin levels in my facial skin my whole life, and now it causes my facial hair to be durable, wiry, and impossible to shave. If I put an electric shaver up to my beard, it just starts tugging my skin away from my neck. My beard is indestructible, causing me to remain an unwilling neckbeard despite my best efforts.

I have heard that even the most extreme methods like electrolysis only last a few years before the hair grows back, and it's really expensive to do.

So I was wondering if some genomics experts could answer this question for me. Is there theoretically a way that you could send a message to each of your facial hair follicle cells to alter their gene expression to permanently "turn off" adult facial hair growth from them?

tl dr; is there can be gene therapy to permanently "turn off" my beard?