but then it has me thinking that maybe I am missing some cases where there really is a deep and informative connection between two apparently different uses of the term.
for example I keep thinking that integral kernels seem to relate to mappings and so maybe to homomorphism kernels?

this is something I have always wondered about - are the different uses of "kernel" related in any way? i guess some are and some aren't?

Wow this is super interesting!!!!

Yeah, I’ve seen videos like that - I think they are made by Stentor-haters who make a big deal out of how the Amoeba wins. But the way I see it amoeba ends up having to engulf the Stentor’s ass so I’m just not sure that’s a win.

you make a really good point - it seems like its mostly giant cells that are good at healing wounds and regenerating, I have always thought maybe cells that are really big have enough cytoplasm that they can survive longer, which gives them time to make repairs. but that's just speculation...

wow really? yeah I would assume so if whatever got wounded had something hard enough? maybe in testate amoebas?

more like something from Carcass!

this has been a wonderful collaboration between our two labs, led by Ambika Nadkarni @biochembika.bsky.social. We are grateful for funding by NIH and NSF

the need to pump water out might not be limited to Stentor - even in humans the extracellular environment isn't always isotonic. When exercise or pathology changes the extracellular milieu, does this affect how cells like cardiac muscle heal wounds?

our conclusion: it's not enough to heal wounds, you also have to restore cytoplasmic composition after any changes that occurred while the wound was open and stuff was bleeding out and water flowing in.

amazingly, this worked! If syntaxin RNAi cells are cut in hypertonic media, they don’t die!

if it is true that Syntaxin's role in wound healing is to restore cytoplasmic osmolarity, then it should be possible to suppress the post-wounding death phenotype by cutting cells in hyper-osmotic media, reducing the drive for water to enter.

Ambika hypothesized that maybe when the cell is cut, water rushes in, and the CV is needed to pump it back out after the membrane heals. In this model, syntaxin RNAi cells die because they can't pump the water back out so the cytoplasm gets too diluted.

while the hull was gashed, water leaked into your boat. So, you use a bilge-pump to pump the water back out. In a sense, the CV is basically a cellular bilge-pump.

but why would a defect in contractile vacuole activity cause cells to die after wounding? That got us thinking: imagine you are in a boat and run over a rock that makes a gash in the hull. You patch it as fast as you can, but you still aren't out of the woods.

in other ciliates, Syntaxins are important for CV fusion and function. Could we be seeing a defect in CV function?

pubmed.ncbi.nlm.nih.gov/17451555/

As with other freshwater protists, Stentor has a contractile vacuole (CV) that accumulates water and then ejects it by transiently fusing with the plasma membrane. These vesicles made us think of CVs that couldn't fuse.