Recent comments in /f/askscience
[deleted] t1_j96czsb wrote
Reply to Just with a sample of someone's DNA, can a lab tell the approximate age of a person? by Blakut
[removed]
th3h4ck3r t1_j96c6u3 wrote
Reply to comment by fack_yuo in Why are fevers cyclical? by Key-Marionberry-9854
That just sounds like a second-degree differential equations with extra steps.
[deleted] t1_j96c0ht wrote
Reply to comment by wewbull in Why are fevers cyclical? by Key-Marionberry-9854
[removed]
yaminokaabii t1_j96bbp2 wrote
Reply to comment by wewbull in Why are fevers cyclical? by Key-Marionberry-9854
Be careful saying that beneficial traits will necessarily become more prevalent. It's all probability. If getting the long-term better trait necessitates going through a worse trait in the short-term, it may never happen. As an example with arbitrary numbers, say staying in fever another 1 to 5 hours is actually disadvantageous, even if staying 5-10 hours is advantageous.
[deleted] t1_j96a747 wrote
[deleted] t1_j96a0yf wrote
Reply to Just with a sample of someone's DNA, can a lab tell the approximate age of a person? by Blakut
[removed]
0oSlytho0 t1_j969ls5 wrote
Reply to Can doctors tell when cancer is caused by something specific, such as smoking or chemicals? by [deleted]
Short answer: no.
but some mutations are more likely in smokers, others in drinkers, drug users etc etc etc. A whole bunch of statistics can show these patterns.
Back from patterns to the individual; Definite proof that your tumor came from smoking is, again, not possible. But it's a likely factor that had an influence.
[deleted] t1_j969127 wrote
Reply to Just with a sample of someone's DNA, can a lab tell the approximate age of a person? by Blakut
[removed]
[deleted] t1_j968yis wrote
[deleted] OP t1_j968ulc wrote
asdaaaaaaaa t1_j968s3c wrote
Reply to comment by akeean in Was reading something related to Rock Salt mining. In places like the Himalayas where rock salt mining is done in cold temperatures, a lot of miners report burns. Why is it so that salt burns in a colder surroundings? Would it be the same reason why the salt ice challenge was so dangerous? by vvdmoneymuttornot
It's how you "make" ice cream at home. You use salt + ice to drop the temperature really cold, really fast.
[deleted] t1_j968a0u wrote
[deleted] t1_j967rd3 wrote
Reply to comment by comparmentaliser in Was reading something related to Rock Salt mining. In places like the Himalayas where rock salt mining is done in cold temperatures, a lot of miners report burns. Why is it so that salt burns in a colder surroundings? Would it be the same reason why the salt ice challenge was so dangerous? by vvdmoneymuttornot
[removed]
MYprivacyisimportant t1_j967g3k wrote
Reply to comment by Gradus83 in Are the flu strains we vaccinate against more or less the same world-wide? by heyheyhey27
so if you spent winter in the southern hemisphere and then winter in the northern hemisphere would a doctor recommend getting both vaccines?
NumberOfTheOrgoBeast t1_j966mnp wrote
Reply to comment by geistererscheinung in Why does the thyroid use iodine ? by geistererscheinung
That's another good question, which again deals with unambiguous signaling. Remember that molecules have not only size in space, but also a shape and a pattern of electron density. So, yes, you could make a protein as big or bigger than T3, but will it fit into the necessary active site the same way? And will it electronically interact with the active site the same way?
For peptides, the bond angles of the main chain are given by something called a Ramachandran Plot, which works out the most likely shapes a peptide bond can form in space. In this case, maybe you could have a protein with a pair of tyrosines that could meet up and maybe look kind of like T3? Well, the necessary bond angles make that unlikely, so such a shape would not persist in space for enough time to matter. Even if it did, you'd have the rest of the protein hanging out at weird angles, preventing a good fit with the intended receptor.
Finally, even if all that worked, there's still some intentional interaction with the iodine substituents necessary to induce a tight fit. You could get a couple tyrosines in there to fake the rough shape, but how are you going to get protein parts in there to fake the iodine interactions? There's no way. (A) nothing else is even kind of shaped like those iodine substituents, and (B) even if there were, you couldn't stick them into that binding site without popping the whole protein out. Thus, the iodine groups help ensure that only T3 will reliably fit into the intended receptor site.
laughingweasel t1_j9661vh wrote
Reply to comment by diamondpredator in Why are fevers cyclical? by Key-Marionberry-9854
And it really slows down the rate that viruses multiply which allows your immune system to reduce the number of viruses that are able to multiply.
[deleted] t1_j965w5q wrote
wewbull t1_j964efw wrote
Reply to comment by Shadowfalx in Why are fevers cyclical? by Key-Marionberry-9854
It's random in the short term. In the long term, beneficial traits will improve survivability and be selected for. If staying in fever benefitted surviving it's reasonable to assume it would have arisen by chance and then been selected for by now.
[deleted] t1_j9634bw wrote
Reply to comment by quaoarpower in How do spider eyes work? by NoMoreMonkeyBrain
[removed]
Bax_Cadarn t1_j9630xk wrote
Reply to Why are fevers cyclical? by Key-Marionberry-9854
I can't say that was ever discussed during patophysiology.
One case which I can speak about is malaria. There, it is due to Plasmodium's life cycle. It takes 3 days for them to mature in a cell. So day 1 they enter the cells, they 4 they burst the cells open, which releases all its crap simultaneously from many cells. Day 7 it's hatching time again etcetc.
I reckon there's also 1 with 4 day life cycle.
[deleted] t1_j962rd0 wrote
Reply to comment by Interesting-Month-56 in Why are fevers cyclical? by Key-Marionberry-9854
[removed]
Shadowfalx t1_j96254v wrote
Reply to comment by wewbull in Why are fevers cyclical? by Key-Marionberry-9854
There also isn't a reason to think the body would evolve a way to stay in fever after vital load drops. Remember, evolution is random and if this never randomly occurred we wouldn't evolve it.
InevitableSignUp t1_j9621ra wrote
Reply to comment by Nyrin in Was reading something related to Rock Salt mining. In places like the Himalayas where rock salt mining is done in cold temperatures, a lot of miners report burns. Why is it so that salt burns in a colder surroundings? Would it be the same reason why the salt ice challenge was so dangerous? by vvdmoneymuttornot
I hate to sound silly, but where does the extra cold come from? Is this assuming the ice/salt mixture is still in a sub-freezing environment? How does putting salt on ice and then onto your skin make the ice colder? Colder enough to cause such damage?
[deleted] t1_j9621n5 wrote
Reply to comment by Vizslaraptor in If a human being is bleeding internally say in their mouth or stomach would they still have a risk of anemia? by Robbeee
[removed]
[deleted] t1_j96d15v wrote
Reply to Just with a sample of someone's DNA, can a lab tell the approximate age of a person? by Blakut
[removed]