Recent comments in /f/askscience

humboldtcash t1_j3f8s7m wrote

Reply to How does DNA encode 3d space/information? by Rit2Strong

There is some degree of spatial information within DNA. There is something called “hox genes” which are arranged on chromosomes in the same order our body parts are arranged (head, neck, thorax, hips, legs, in that order). There have been experiments where fruit flies genomes were edited. Basically the hox genes positions were changed and the flies has feet instead of antenna on their heads.

More precise spatial information such as having 5 fingers that are on the end of your arm is given by cell signaling mostly. During the development of an embryo most things are related to cells releasing certain molecules that cause other cells to move or differentiate. But the actual code for all those things is in our DNA as well. However the exact processes are still being researched and it’s not 100% clear how it works.

Edit: just a thought that occurred to me: I think if we knew the exact mechanisms of how this works, medical science would be creating functioning 3D organs or something close to that

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CryptographerSmall45 t1_j3f8e64 wrote

Reply to Are gaiters at least partially effective at blocking aerosols? by Lokarin

No, they aren't "worse than nothing." They just got that reputation based on misinterpreted results of one study that got a lot of press (https://www.scientificamerican.com/article/how-those-bogus-reports-on-ineffective-neck-gaiters-got-started/). That said, any kind of cloth face covering isn't really recommended anymore for the prevention of COVID-19. That was back when it was believed to be primarily spread through respiratory droplets. Once they determined it could be spread through aerosols (and indeed that the later more contagious variants are like primarily spread via aerosol transmission), the recommendation shifted away from cloth face covering of any kinds and to surgical and N95 masks.

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Plane_Pea5434 t1_j3f7t77 wrote

Reply to What happens physiologically when we brace ourselves for things? by bee1413

Not really sure how to explain it but the basic idea is that the reaction is harder, let’s say for example there’s an explosion or other loud and sudden sound, if you are distracted you simply get a big stimulus from nowhere and it can probably be dangerous so your fight or flee mechanisms kick in, your pupils dilate, your muscles tense, your heart beats faster, essentially all your senses are enhanced and that makes it feel more intense while when you are expecting it there’s no adrenaline rush so it feels “normal”

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argenbar t1_j3f7lne wrote

Reply to Are gaiters at least partially effective at blocking aerosols? by Lokarin

This study found neck gaiters were about 47% effective at source control (stopping you making someone else sick). While they didn't look at it, if it was well sealed around the nose it would probably be similarly effective for personal protection. A sealed n95 is going to be 95%+ effective, and wearing no mask at all will be 0% effective. So a neck gaiter is going to better than nothing, but it's not a substitute for a n95 (or even a surgical mask) in risky situations e.g. close quarters, poorly ventilated spaces (busses, bathrooms) etc. Outside, ventilation is much much better, so it probably doesn't matter as much what you wear.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9345365/

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