Title Information
Title
Driving Forces for Cell Cluster Shape Evolution and Stability
Name: Personal
Name Part
Nurse, Asha K
Role
Role Term: Text
creator
Origin Information
Copyright Date
2011
Physical Description
Extent
xiv, 124 p.
digitalOrigin
born digital
Note
Thesis (Ph.D. -- Brown University (2011)
Name: Personal
Name Part
Freund, Lambert
Role
Role Term: Text
Director
Name: Personal
Name Part
Bower, Allan
Role
Role Term: Text
Reader
Name: Personal
Name Part
Chason, Eric
Role
Role Term: Text
Reader
Name: Corporate
Name Part
Brown University. ENGINEERING: Solid Mechanics
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
Observation of self assembly of clusters of cells in three dimensions has raised questions about the forces that drive the changes in shape of the cell clusters and the stability of the clusters formed. Cells that self-assemble into a toroidal cluster about the base of a conical pillar have been experimentally observed to spontaneously climb the conical pillar. In other cases, toroidal clusters do not climb the pillar but, instead, they may undergo localized thinning at one or more cross-sections around the circumference of the cluster.Assuming that cell cluster reorganization is due solely to surface diffusion, a mathematical model based on thermodynamics of an isothermal dissipative system is presented. The model shows that the cluster can reduce its surface area by climbing the conical pillar but at the expense of increasing its gravitational potential energy. As a result, the kinetics of the climb is affected by parameters that influence this energy competition such as the slope of the conical pillar or the surface mobility of the diffusing cells. The development of localized deformations in clusters that do not climb the conical pillar is examined by means of a linear stability analysis wherein a nominally uniform toroidal cluster has its shape perturbed by a periodic perturbation in its minor radius. Analysis reveals that the cluster is stable if the surface energy density is spatially uniform. However, if the surface energy density is allowed to vary from point to point around the circumference of the toroid, unstable configurations may develop. The stability of the cluster is observed to depend on its initial minor radius, the radius of the conical pillar and the wave number of the applied sinusoidal perturbation. A stability analysis of nominally cylindrical bodies which evolve in shape due to surface diffusion was then carried out to understand the role of nonlinearity in the stability criteria in such bodies. This analysis may serve as a basis for a future study of the stability of toroidal clusters or toroidal shapes beyond the range of linear behavior.
Subject
Topic
shape evolution
Subject
Topic
cell clusters
Subject
Topic
thermodynamic driving force
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1012085")
Topic
Mathematical models
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20111003
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0MP51HK
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations