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Bones are complex, slow moving fluids. Stumbling from developmental biology into fluid mechanics. A cry for help.

We are a bunch of developmental geneticists on Gibbet Hill and have over the past few years found out that bones are anything but hard solid objects. We have discovered a three-layered organization and the cells making up this organization. it turns out that bones display an inflationary growth, cells move in from both sides into a middle layer like water molcules into a sponge - with the difference that the water particles are forming AND decaying the growing sponge at the same time...and there appears to be migrations across the layer throughout development. these bones are like foams but each foam cell is being invaded by new sets of cells making more walls and 'bubbles' (which we call cancellae) on the inside of older bubbles. we know that the cells making the bony matrix stuff are also the ones decaying it - but perpendicular to their migratory path.

Doing some fancy genetics enabled us to see entire bones for the first time at single cell resolution. As cells of the same origin carry one out of several genetically encoded colours we can start to reconstruct the underlying dynamics of cell migration and the spread of cells .If cells correspond to the particles in fluids, their speed of migration should correspond to the local temperature in a fluid. We have additional complications as the thickness of the fluid varies in the plane and that the number of particles increases with time (cells divide). Despite these events, there is order in the flow of cells, this is not random diffusion, there are eddies and patterns to cellular behaviour that are reminiscent of Benard Cells and convection systems, we see rolls, ribbons in thin areas, morphing into hexagonal (honeycomb like structures in thicker more central bone areas). I am looking for partners in fluid mechanics (theoretical and experimental) to start to understand bones as fluids, understand the nature of your models and parameters as an uneducated layman and then try to work out jointly with you the biological correlates of the physical parameters you are using: to arrive at a proper and useful description of these complex objects that help explain these patterns. This might enable us to predict and grow bones at some point but i am really more interested how these complex systems grow, work and morph in the first place: why are there patterns emerging here, how can we understand why certain pattern exist at certain places and why do they change when bones grow in thickness? What does that tell us about the motions of particles in these areas? how coudl they be coordinated? I am looking for partners in that in fluid mechanics and engineering who share my obsessions with patterns . we have measurements of various kinds of these cells, their spread, their spatial patterns in 3D,the similarity across cellular layers etc that could help. So this is all quite perplexing, an adventure into understanding mesmerizing patterns in 3D structures that are behaving like slow running fluids (or maturing foams) displaying convection, entirely uncharted territory for traditional biologists, but here you go. None of this is published. Thanks for coming and having a look! Figure attached. Look forward to lively discussions.

Cheers

Georgy