Voyages, migrations, errances

Peyton Rous and his voyages of discovery.

Step-by-Step Migrations

This paper considers a dynamic model of industry location in which there is a tension between two forces. First, there is the agglomerating force of preference of intermediate input variety that tends to keep an industry at its original location. Second, other location factors matter and these tend to pull the industry in the direction of a new location. A crucial aspect of the model is that th...

Health, Medicine, and the Sea: Australian Voyages, c.1815-1860

Military men, as histories of the Royal Navy in particular have shown, tend to be interested in controlling sanitary conditions. Among seamen, maintaining health was always essential otherwise ships could not remain at sea. The main theme of Dr. Katherine Foxhall’s interesting book is voyages to Australia. On these voyages the internal environment of the vessel was the same, whether those on bo...

Guiding neuronal cell migrations.

Neuronal migration is, along with axon guidance, one of the fundamental mechanisms underlying the wiring of the brain. As other organs, the nervous system has acquired the ability to grow both in size and complexity by using migration as a strategy to position cell types from different origins into specific coordinates, allowing for the generation of brain circuitries. Guidance of migrating neu...

Mutations or Migrations

We study the ABC model in the cyclic competition (A+B → 2B, B+C → 2C, C+A → 2A) and the neutral drift (A+B → 2B or 2A, B+C → 2C or 2B, C+A → 2A or 2C) versions, with mutations and migrations introduced into the model. When stochastic phenomena are taken into account, there are three distinct regimes in the model. (i) In the “fixation” regime, the first extinction time scales with the system siz...