Ken A Dill | Searcharxiv

arXiv2019

Minimal constraints for Maximum Caliber analysis of dissipative steady state systems

Maximum Caliber (Max Cal) is purported to be a general variational principle for Non-Equilibrium Statistical Physics (NESP). But recently, Jack and Evans and Maes have raised concerns about how Max Cal handles dissipative processes. Here, we show that the problem does not lie in Max Cal; the problem is in the use of insufficient constraints. We also present an exactly solvable single-particle model of dissipation, valid far from equilibrium, and its solution by Maximum Caliber. The model illustrates how the influx and efflux of work and heat into a flowing system alters the distribution of trajectories. Maximum Caliber is a viable principle for dissipative systems.

cond-mat.stat-mech↗

arXiv2016

How did prebiotic polymers become informational foldamers?

A mystery about the origins of life is which molecular structures $-$ and what spontaneous processes $-$ drove the autocatalytic transition from simple chemistry to biology? Using the HP lattice model of polymer sequence spaces leads to the prediction that random sequences of hydrophobic ($H$) and polar ($P$) monomers can collapse into relatively compact structures, exposing hydrophobic surfaces, acting as primitive versions of today's protein catalysts, elongating other such HP polymers, as ribosomes would now do. Such foldamer-catalysts form an autocatalytic set, growing short chains into longer chains that have particular sequences. The system has capacity for the multimodality: ability to settle at multiple distinct quasi-stable states characterized by different groups of dominating polymers. This is a testable mechanism that we believe is relevant to the early origins of life.

q-bio.BM↗