Recent comments in /f/askscience

Washburne221 t1_jc5jr4t wrote

On Io, Jupiter's moon, extreme tidal forces produce intense volcanic activity. But because of its distance from the sun the surface is quite cold (-130 C) and the volcanic gasses released literally freeze out of the atmosphere, producing drifts of sulfur dioxide snow, which can be revaporized by flows of molten sulfur from the volcanoes. So Io has a sulfur cycle.

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S_A_N_D_ t1_jc5j4r1 wrote

Protein denaturation happens because the tertiary structure is broken as the charged and polar interactions of each residue are broken or disrupted. Salt will have little impact on the peptide bond.

Death due to salinity is usually due to organisms being unable to maintain a proper intracellular osmotic balance rather than from direct protein denaturation.

Hypersaline solutions may cause some of the DNA to precipitate, however I'm not sure if it will have a net negative, or net positive effect. I'm actually leaning towards it possibly having a protective effect, but I'm not sure I have the background in biochemistry necessary to say that from a position of authority.

Overall though I expect it would be unlikely to make any measurable change to the numbers listed above, especially since the calculated half life was for samples that were buried and are therefore surrounded by a lot of minerals as well, and therefore also likely salts. I'm guessing any protective effect from our example would be insignificant.

Edit: Here is an article that does suggest high salt concentrations have a net protective effect on DNA preservation in the environment, though the study does suffer from some major limitations so we are unable to conclude to what degree this would have relative to the paper I mentioned in my first post. I expect it might skew the half life to the longer end of the range, but to what degree I can't speculate.

https://www.nature.com/articles/srep22960

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figmentPez t1_jc5hnvi wrote

>it's unlikely salt water would have any significant net positive effect on preservation length of time.

Given that high salt concentrations denature proteins, I'd suspect that the opposite is the case. Salt so concentrated that it causes life to die seems like it would cause DNA to break down faster.

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Stillwater215 t1_jc5caks wrote

Passively safe reactors should be the future of electricity generation. Modern reactors are designed so that the job of the operators is to “fight” the reactor to make it more reactive. If they walk away or are incapacitated, the reactor brings itself into a steady, low-power state. But whenever people think of nuclear power, they only think of Chernobyl…

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Ayad3 t1_jc5920j wrote

Why? For the same reason our reactors do not have containment buildings around them, like those in the West. For the same reason we don't use properly enriched fuel in our cores. For the same reason we are the only nation that builds water-cooled, graphite-moderated reactors with a positive void coefficient. - It's cheaper.

  • Valery Legasov
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