Recent comments in /f/askscience

UseYourThumb t1_j5wa8ui wrote

Reply to comment by Unknown_Predator88 in i was reading an article that mentions GABA and how different isoforms mediate “fast” and “slow” hyperpolarization. what is meant by “fast” and “slow” in the context of hyperpolarization? by Unknown_Predator88

I agree with the paper, I don't think I would technically call it an agonist. Read sections 6, 7, and 8 of this more recent review for a better explanation.

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farrenkm t1_j5w9k8d wrote

Reply to comment by quats5 in What determines whether we can create a vaccine for an illness or not? by ShelfordPrefect

I started working for a local hospital system around the turn of the century. They asked if I was up-to-date on my vaccines, and I said yes. Brought in the hep B documentation and everything.

Then they asked: have you ever had chicken pox? Dunno. Not that I'm aware of. They drew a titre and -- nope, no antibodies. They gave me the vaccine late 20's, early 30's. My next question, that I'll ask my MD, is if I need to worry about shingles. If I never had chicken pox, if I had the vaccine, should that be protection enough so I don't need to worry about it? My first reaction is "yes, that's true."

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odddutchman t1_j5w958r wrote

Reply to comment by electric_ionland in Why do sample return missions such as OSIRIS-REx use their own reentry vehicles instead of just going to the space station for pickup and return with ISS equipment? by PromptCritical725

Strictly speaking, they don't get the atmospheric braking for free...still needs a heatsheild and guidance system; but they don't have to drag extra mass of fuel, rocket engines, etc with them during the ascent part of the flight...which adds up REALLY fast. Look up "the tyranny of the rocket equation".

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nexpermabad t1_j5w89bn wrote

Reply to What determines whether we can create a vaccine for an illness or not? by ShelfordPrefect

Everyone mentioning HIV attacking the immune system is incorrect. The problem is that HIV is incredibly mutable. We create many antibodies that bind to HIV, however HIV can mutate to escape them. There is a conserved portion of HIV (the part where it binds to CD4 T-cells) that a few antibodies called broadly neutralizing antibodies (bnAbs) are able to target. However, these bnAbs are relatively rare, and tend to happen in patients who have had HIV for a while.

It's incredibly difficult to generate these bnAbs from a vaccine. Your body generates tailored antibodies through a process of mutation and selection called affinity maturation. These HIV bnAbs require a ton of mutation. There is research on trying to shepherd B cells through many rounds of mutation and selection to create these bnAbs by vaccinating with multiple different antigens, but this is still a very difficult problem.

Another difficult vaccine is malaria. We have vaccines that create antibodies that help protect against malaria. However, having antibodies to a foreign protein diminishes our ability to further develop an immune response to said foreign protein. As a result, current vaccine candidates have struggled with creating a large enough antibody response to generate strong protection.

Source: I'm a soon-to-be Ph.D. graduate in a computational vaccine design lab.

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reddit_poopaholic t1_j5w70bi wrote

Reply to Ask Anything Wednesday - Economics, Political Science, Linguistics, Anthropology by AutoModerator

Question about building cheap fully auto-pilot [capable] EVs...

How much would it cost to build an EV that is designed like a fully-enclosed golf cart, maxes out at 60mph, and equipped with auto-pilot [upgradeable cruise-assist] technology?

How much weight could be reduced from consumer EVs if they were constructed in the aforementioned way, and how could the weight reduction impact the vehicles potential range?

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Unknown_Predator88 OP t1_j5w6sd2 wrote

Reply to comment by UseYourThumb in i was reading an article that mentions GABA and how different isoforms mediate “fast” and “slow” hyperpolarization. what is meant by “fast” and “slow” in the context of hyperpolarization? by Unknown_Predator88

https://pubmed.ncbi.nlm.nih.gov/16402094/

I also wanted to clarify; My P.I. referred to benzodiazepines as an agonist of GABA, but this paper mentions that they potentiate GABA by increasing channel frequency; this is confusing to me and i have to present an overview of it at our lab meeting on friday. Thanks.

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quetric t1_j5w6n75 wrote

Reply to Why do sample return missions such as OSIRIS-REx use their own reentry vehicles instead of just going to the space station for pickup and return with ISS equipment? by PromptCritical725

In addition to what others have said about delta-v required to match the orbital speed of the ISS, there's also the challenge of matching its inclination. Most likely a sample return mission will occur roughly in the solar system invariable plane, since that's where most of the planetary mass is. The ISS orbits at a relatively high inclination and I suspect it would take some creative gravity assists or a lot of delta-v to get in alignment with it.

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