Figure - PMC

Skip to main content

An official website of the United States government

Here's how you know

Here's how you know

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

View full-text article in PMC

. 2014 Oct 21;9(10):e110415. doi: 10.1371/journal.pone.0110415

Search in PMC
Search in PubMed
View in NLM Catalog
Add to search

© 2014 Caffrey et al

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.

PMC Copyright notice

Allowed moves are up, down, left, right. The probability that a vertical move is attempted (either up or down) is , while the probability that a horizontal move is attempted (either left or right) is , where . We take , so that vertical moves in either direction are much more frequent that horizontal moves. For each movement rule illustrated, the motile agent (black) attempts one of the four possible moves with the probability shown. In the IZ, agents have a constant bias parameter . In the CP, the parameter is used to quantify the extent of relative preference between up and down moves. Four movement mechanisms are considered: (a) random movement with no preferred vertical direction throughout the CP; (b) a spatially uniform upward bias (e.g., due to a constant chemotactic gradient) throughout the CP; (c) no preferred vertical direction close to the intermediate zone, but a short-range bias towards Layer I for neurons within a distance of Layer I (corresponding to a local attractive signal as Layer I is approached); (d) no preferred vertical direction close to the intermediate zone, but a short-range bias away from Layer I for neurons within a distance of Layer I (corresponding to a local repulsive signal as Layer I is approached).

Inline graphic — Allowed moves are up, down, left, right. The probability that a vertical move is attempted (either up or down) is , while the probability that a horizontal move is attempted (either left or right) is , where . We take , so that vertical moves in either direction are much more frequent that horizontal moves. For each movement rule illustrated, the motile agent (black) attempts one of the four possible moves with the probability shown. In the IZ, agents have a constant bias parameter . In the CP, the parameter is used to quantify the extent of relative preference between up and down moves. Four movement mechanisms are considered: (a) random movement with no preferred vertical direction throughout the CP; (b) a spatially uniform upward bias (e.g., due to a constant chemotactic gradient) throughout the CP; (c) no preferred vertical direction close to the intermediate zone, but a short-range bias towards Layer I for neurons within a distance of Layer I (corresponding to a local attractive signal as Layer I is approached); (d) no preferred vertical direction close to the intermediate zone, but a short-range bias away from Layer I for neurons within a distance of Layer I (corresponding to a local repulsive signal as Layer I is approached).