Recent comments in /f/askscience

Jaralith t1_j51c6dh wrote

Reply to comment by Roadgoddess in Is there any difference in efficacy when a vaccine is administered somewhere other than the upper arm (e.g. on the foot)? by MercurioLeCher

The vaccine itself isn't meant to spread through the body. What it does is activate immune cells that were already hanging out in the muscle (generally macrophages), and those activated immune cells release chemical messengers called cytokines to call other types of immune cells to the site.

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vilhelm_s t1_j51bk1j wrote

Reply to How is protein folding quantum mechanical? by prionprion

I think it's not extremely "quantum". Of course proteins are molecules so they ultimately obey quantum mechanics, but I think for the folding problem people are not really treating that---they just consider the parts of the chain as having well-defined positions in 3d-space, and add up energy from pairwise interactions between the parts that end up close to each others. (Finding the minimal energy configuration here is already very difficult, even before starting to consider any quantum superpositions or trying to compute the pairwise interactions more exactly).

However, some people hope that quantum computers could still be helpful, e.g. this recent paper. The problem they are solving is still the classical, non-quantum setup, but there are quantum algorithms that are supposed to be good at searching for minimal-energy configurations, so it may still speed things up.

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[deleted] t1_j51ahsb wrote

Reply to Why do our eyes track moving objects smoothly, but skip when moving our focus point along a surface? by tikkymykk

My two cents, evolutionary it makes more sense and is more efficient. If you are in the savanna, you need to quickly see static points and observe their detail to see if there is any threat. If the thing moves you need to keep focus on the moving thing as it might kill you.

smoothly tracking static things is too much unnecessary info, at least, at least that is what nature decided for us

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im_thatoneguy t1_j5164ex wrote

Reply to comment by Silverjeyjey44 in Is there any difference in efficacy when a vaccine is administered somewhere other than the upper arm (e.g. on the foot)? by MercurioLeCher

One reason recently is illustrated by the rare cardiac side effects from the various Covid vaccines. There's evidence to suggest that the virus' spike proteins themselves can cause damage to cells even just as non-functional fragments. So a sore and inflamed arm muscle from your deltoid muscle cells reacting to the spike proteins is fine. But if your heart gets hit by a bunch of Covid Spike proteins and gets inflamed that may be what's causing myocarditis even though they aren't being infected by a virus.

https://newsroom.heart.org/news/coronavirus-spike-protein-activated-natural-immune-response-damaged-heart-muscle-cells

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pintofgeodesy t1_j515rju wrote

Reply to Is there any model or method to calculate how groundwater distributes spatially? by EggLemon3000

Modflow comes to mind as a modelling tool. Note that a lot of things influence this process. Initial state, to what extent is the soil already saturated, where is the groundwater table? What is the hydraulic conductivity of the subsurface? Vegetation, surface temperature, wind, humidity, incoming radiation all influence evapotranspiration losses too.

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ohheyitslaila t1_j515r2u wrote

Reply to comment by stickymaplesyrup in Given that reproduction is difficult or impossible when both animals have different numbers of chromosomes, how did so many species evolve to have so many different numbers of them? by MercurioLeCher

You actually picked a really interesting set of animals for your example!!! I apologize if I explain anything poorly, I just know a little about this stuff because my family breeds horses. I feel like this kind of hits on what you’re asking.

So female horses and male donkeys can be bred to each other, that produces mules. Female mules have 63 chromosomes, which can’t usually be split evenly to produce a fertile egg. BUT, some female mules actually produce an egg that does have an even set of chromosomes. It’s just that the egg rarely meets up with a sperm with a matching set of chromosomes. A case of this incredible, one in a million chance did occur and a female mule gave birth to a male foal in 2007. The foal had some deformities, believed to be caused by the chromosomal issues, specifically a problem with its legs. But it lived until about 2010, when it slipped on ice and was badly injured, leading to him being humanely euthanized.

I wonder if that kind of thing could happen in humans. It would probably be just as rare, if not more so.

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