Age-size population dynamics: Derivation of a general matrix methodology

Residual volume in a general population. Effects of body size, age, cigarette smoking, and respiratory symptoms.

Residual volume (RV) was obtained by subtracting vital capacity from total lung capacity determined by the single breath helium dilution (TLCsb) to measure CO diffusing capacity in 2,680 subjects (8 to 64 years old) of a general population sample. There were 712 normal subjects (243 male and 469 female subjects) selected to evaluate the pattern of RV by age and to derive reference values for in...

Positive Global Solutions for a General Model of Size-dependent Population Dynamics

We are concerned with size-structured population models of general type with the growth rate depending on the individual’s size and time. In [3], the local existence and uniqueness of the solution have been investigated. In this paper, we discuss the positivity and global existence of the solution as well as L∞ solutions. As is explained in [3], the model in our mind is the population dynamics ...

Local Stability of a Quasi-linear Age-size Structured Population Dynamics Model

The local stability of a quasi-linear age-size structured population model studied in Tchuenche (2007) is analysed. If a certain threshold parameter known as the basic reproductive rate is less than unity, then the trivial steady state is locally asymptotically stable. Also, it is shown that if the only real root of the equation R(m′) = 1 is negative, then, the non trivial steady state is local...

Matrix Models and Population Dynamics

Transient population dynamics in periodic matrix models: methodology and effects of cyclic permutations.

Many biological populations are subject to periodically changing environments such as years with or without fire, or rotation of crop types. The dynamics and management options for such populations are frequently investigated using periodic matrix models. However the analysis is usually limited to long-term results (asymptotic population growth rate and its sensitivity to perturbations of vital...