S_A_N_D_

S_A_N_D_ t1_jdt2rqn wrote

In general, local laws typically superseded maritime laws. Rarely however do local laws conflict in this regard, and usually it's local laws will be a more strict version of the maritime law (such as environmental restrictions). Where this might not hold up is if the vessel was in international waters (more than 12 NM from the Italian coast) then the Italian laws would and could not apply. Then it just becomes a question of access to Italian ports, which isn't guaranteed. I'm not sure how they could be fined however if they were not in Italian jurisdiction and didn't break any IMO law.

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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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S_A_N_D_ t1_jc4fek2 wrote

This is a relevant article on the subject.

https://www.nature.com/articles/nature.2012.11555

>After cell death, enzymes start to break down the bonds between the nucleotides that form the backbone of DNA, and micro-organisms speed the decay. In the long run, however, reactions with water are thought to be responsible for most bond degradation. Groundwater is almost ubiquitous, so DNA in buried bone samples should, in theory, degrade at a set rate.

Basically, unless the sample is preserved under unnaturally dry conditions while also conveniently protected from all other sources of degradation (something that is unlikely to happen naturally), you're looking at best case scenario of ~7 million years, though the most likely would be ~1 million years.

As water is the main contributing factor, it's unlikely salt water would have any significant net positive effect on preservation length of time.

Edit: Here is an article I found that suggests high salt anoxic conditions will have a net protective effect, however the study does have some limitations. Overall, it might suggest that a high salt environment might help skew the half life to the longer end of the spectrum, though I'm unable to suggest it may extend it beyond that to any significant degree.

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

Also I didn't truly answer your question. I would expect that we would be able to extract DNA from the organisms you are looking at in those salt pools, however the success would decrease with time. After about 500 years, about 1/2 the DNA bonds would be broken, and 500 years after that another half would be broken. We can piece together fragments of DNA to make up the whole (sort of like piecing a puzzle back together), but the chance of success would decrease with time. The further back you go, the more samples you'd need to get a complete picture, and after about a million years the task would pretty much become impossible even if you had an abundance of well preserved samples.

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S_A_N_D_ t1_jbrx7vt wrote

Viruses equally rely on their host for binding, cell entry, and replication.

The further we get from these viruses time wise, the less efficient it will likely be at the above.

I really hate these scare articles because there is very little to suggest these viruses actually pose a risk. There is however real risk from organisms that are currently co-evolving their virulence in tandem with us right now.

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S_A_N_D_ t1_j5qygka wrote

I would argue it's stronger than the in-vitro study. All the found there was that it activates general stress responses. Stress responses are known to decrease susceptibility to antibiotics (which is the effect saw in vitro).

It's in the same category as fire, because excessive heat also activates stress response pathways. What matters is whether it has an effect in the real world, and so far the data says it doesn't.

Overall it's worth studying further, but right now the best evidence says no effect.

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S_A_N_D_ t1_j5qu15u wrote

The evidence is really really weak.

The found no coorolation between antidepressant consumption and antibiotic resistance in a population study which means even if there is an in vitro effect, it's so far not translating into real world effects.

>After reading the article, González Zorn decided to check if there was any correlation between the different levels of consumption of antidepressants in European Union countries and levels of antibiotic resistance, but found none. 

And then they throw in this little nugget to somehow try and pull it back.

>Such a correlation, however, does exists when other factors are taken into consideration, such as the number of drugs consumed without prescription.

This isn't even even relevant to the article at hand. It also doesn't take into account other drugs either because that's not what they're testing. They were looking at anti-depressants and the results came up negative.

The mechanism they suggest is just general stress response which leads increased mutations and horizontal gene transfer (more on this later).

They did in vitro studies and found the inhibitory concentrations of various antibiotics increased. The above mechanism can't explain this because this would require either de novo resistance mechanisms to just evolve in the short timeframe (incredibly unlikely), and presumably they didn't have resistance genes in the bacteria (which eliminates horizontal gene transfer) since you'd just end up selecting for those with the resistance marker.

Basically they found that antidepressants activate bacterial stress responses. Bacterial stress responses are known to increase antibiotic resistance. But when they looked to the real world, there was no effect.

In short, anti depressants activate bacterial stress pathways. There is no evidence for it causing an increase in antibiotic resistance in individuals taking anti depressants.

>Now, it would be necessary to see if the same results that have been seen [in cell cultures] can be reproduced in vivo, in animal models, and see other effects, such as what happens with the microbiome.”

That was looked at previously. That's what coorilation study was looking at. They found no signal. So this suggests it's not a problem.

I'm not suggesting that we shouldn't study this, only that so far the best evidence we have says it's not actually causing an increase in resistance, even though the in vitro study says it's possible.

This is a really crappy article because right now the best evidence suggests that antidepressants are not causing an increase in antibiotic resistance.

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S_A_N_D_ t1_j252bbz wrote

My point wasn't that it won't look good. My point was that if ever you decide you want a flat roof or some other texture, removing the popcorn becomes a real PIA after it's been painted. OP specifically made a comment about removing the popcorn later. If that's in the cards at all, they should not paint it.

I'm also guessing OP will be rolling and not spraying which will possibly have poorer results. Rolling an uneven surface can be tricky and may not work well.

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S_A_N_D_ t1_j2460a1 wrote

Seconded. DO NOT PAINT OVER POPCORN CEILING OP.

Popcorn ceiling is not hard to remove. It's just messy and time consuming. Popcorn ceiling that has been painted over is a whole different story because the paint is now acting as a layer of glue over top.

Easier to remove does not mean easy to remove. Any paint will make it much harder to remove in the future.

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