לוח שנה משולב

We study the scheduling problem of a self-replicating factory. We find that the distribution of optimal replication times has a universal shape. We show that optimality is achievable by random decentralized “critical” scheduling algorithms, that are biochemically feasible. Compared to a serial self-replication factory, this optimal scheduling factory runs faster by allowing several production lines to run in parallel. The excess inventory then decouples these lines, resulting in a universal extreme value distribution for the replication time. We postulate that bacteria that are evolutionary tuned for fast replication, combine this load-balancing scheduling strategy to optimally control the number of parallel self-replicating units within them. We analyze recent data on growth of E. Coli and obtain a good agreement with the measured distribution of division times from which we also infer the growth rate without further fitting parameters. We discuss future prospects for extension and possible experimental tests.

The nuclear neutron-proton contact is introduced, generalizing Tan's work, and evaluated from medium energy nuclear photodisintegration experiments.
To this end we reformulate the quasi-deuteron model of nuclear photodisintegration and establish the bridge between the Levinger constant and the contact. Using experimental evaluations of Levinger's constant we extract the value of the neutron-proton contact in finite nuclei and in symmetric nuclear matter. Assuming isospin symmetry we propose to evaluate the neutron-neutron contact
through measurement of photonuclear spin correlated neutron-proton pairs.