Recent comments in /f/askscience

enterpriseF-love t1_j274edj wrote

Reply to Is the BF.7 mutation of Omicron less severe than variants? by Active_Bedroom_5495

BF.7 actually refers to the name of the variant where each variant will have a whole host of mutations that define it. That aside, the current epidemiological situation in China results from the dropping of their "zero covid" policy. Due to this alone, there are a couple things happening:

  • BF.7 is highly immune evasive, people vaccinated in China (even with 3 doses) are very unlikely to be protected from infection. Vaccination coverage is extremely low in the most vulnerable age groups. ~40% of elderly above age 80 have a 3rd dose, ~70% have 2 doses. This likely increases the amount of deaths reported as BF.7 does not show any noticeable changes in clinical severity compared to other Omicron subvariants. At the current time, it's more likely we're seeing a founder effect where the initial strain to first hit the population will dominate the landscape regardless of how fit the virus is. For example, XBB is way more fit to sweep China but that isn't happening (yet). This leads into my next point:

  • We're seeing unprecedented infections in a population that is largely infection naïve. Compared to the rest of world where there is stronger hybrid immunity built up from vaccination + infection induced immunity, China is facing the 1st wave in a population with solely boosted immunity. As seen in the rest of the world, current variants were capable of causing waves every couple months in spite of infection-induced immunity.

  • 3 doses (Coronavac) + BF.7 infection also does not provide strong protection from infection against the variants that are currently the most dominant around the world (XBB and BQ.1.1).

On the other hand there are some upsides:

  • BF.7 has circulated widely around the world and was detected in many different countries prior to China's current predicament. BF.7 was de-escalated from monitoring in the UK for low growth rates. BF.7 still makes up a sizeable proportion of sequences at the moment (<10% depending on the country) but BQ.1.1, BQ.1.1.10, XBB.1 and XBB.1.5 are now currently the variants to watch.

  • China's approval of an inhaled vaccine may help to curb infections. Something the rest of the world should adopt. Though it's unknown how widespread its deployment is and whether it was given to enough people to curb infections (unlikely considering the numbers we're seeing)

That said, there is definitely cause for concern. Globally, sequencing for SARS-CoV-2 has dropped 90% and widespread infections in such a large population (in a short time) could be cause for worry due to the possible emergence of a new variant. Certain countries are in response testing for novel mutations that might pop up from inbound travelers.

For further reading:

on variants and mutations

overview of BF.7

Coronavac vaccine against dominant variants

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Ferocious_Armadillo t1_j2734lr wrote

Reply to comment by SonicPixels in If stomach acid id HCl then what happens when you drink water? by SonicPixels

Yes. And back to your original questions…

Yes water molecules get protonated to form H3O+. These molecules get filtered out into blood from capillaries in the small intestine as part of digestion.

Then, in the blood, the amount of H3O+ gets really tightly regulated (turning between H3O+, H2O and OH-) by a bunch of specific molecules that are called buffers (a sort of category of molecules) that regulate the pH of your blood.

If the pH of your blood falls too far out of this range, by having too many/few of these H3O+ molecules, or a breakdown of the above process/other molecules involved, having too few/too many buffers, etc. that can be very deadly, very quickly.

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Bladestorm04 t1_j270vyy wrote

Reply to comment by Aseyhe in How fast does the Milky Way spin? How far does Earth move through space in a year? by Sabre-Tooth-Monkey

Can you explain more this rest frame?

Ive always known there is no such thing as one key inertial reference frame, and all speeds are relative. But if I understand correctly you are suggesting there is something that can take this place, at least in the local galactic group. CMB I thought indicates everything is moving away from us in similar amounts in every direction, making it appear that we are in fact the centre of the universe, until we find out that these observations would be the same for all observers, and therefore we aren't a special case at all.

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Benjaphar t1_j26zlcr wrote

Reply to comment by Narwhal_Assassin in How fast does the Milky Way spin? How far does Earth move through space in a year? by Sabre-Tooth-Monkey

> There also is no “absolute” speed: everything is relative to something else, whether it’s the earth or the sun or the CMB or whatever

Couldn't we say that the speed of light is the absolute standard?

If it were possible to measure it accurately somehow, you could send photons away from you in opposite directions and determine your true motion through space based on how quickly the photons moved away from you. Let's say you got lucky and happened to pick the direction of your true motion as one of your two directions. The photons moving the same direction you are moving would be blue-shifted as they are receding from you at c - (your true speed) and the ones going the opposite direction would be red-shifted at c + (your true speed).

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canadave_nyc t1_j26yqlr wrote

Reply to comment by Aseyhe in How fast does the Milky Way spin? How far does Earth move through space in a year? by Sabre-Tooth-Monkey

Thank you. I'm finding it hard to understand how, if everything in the universe is moving away from everything else (aside from local gravitational interactions), using the classic "expanding balloon" analogy, how are we moving in an identifiable particular direction relative to the "largest reference frame in the universe". I would've thought that we'd be "stationary" with respect to the CMB if everything is moving away from everything else.

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