spectrum of an operator; the main result here is on perturbing the essential ... theory for a semigroup of operators is reviewed; special attention is paid to positive ...
We first recall what Ryabov calls a "special solution": DEFINITION ([6]) . A "special solution1' is a solution of (L) , defined on R , growing at most exponentially, ...
global solution, dissipative operator, semi-inner product, strictly convex norm, ... term, we are interested in finding periodic (resp. almost periodic) solutions. A.
As a consequence of cell division, the number of cells doubles and the positions ... the daugher cell has obtained her share (Y) of RNA, her fate is determined.
We will henceforth be concerned only with finding G on (0,7), where i is the first value for which y() = ï and consequently where 8(T) = 0, admitting the possibility.
by a non-linear transport equation that contains terms responsible for the growth of phytoplankton aggregates, their ... to the above two, rather elementary.
dition for asymptotic stability in a general linear delay-differential equation with impulses. ..... Now we simplify both formulas (19) and (22), for Ï â¤ tj < t. In fact by ...
Sep 29, 2003 - on Mathematical Population Dynamics. He participated as plenary ... with their former teacher, now late friend. ... Biology, J. Theor. Biology, J.
The aim of this work is to study a model of age-structured population with two ... methods (see, for example, the latest edition of the book by Kevorkian and Cole [15]; ..... Depth acts through the temperature which generally decreases down the.
gration has received less attention than other population variables and few models have introduced ... added to death and migration factors, gives zero. The total ...
Journal of Differential Equations 181, 1â30 (2002) doi:10.1006/jdeq.2001.4076, available online at http://www.idealibrary.com on. Semigroup Properties and the ...
In this paper, we discuss the fundamental linear theory for a large class of ..... Lemma 4 (T(t))tâ¥0 defined by (8) is an algebraic semigroup of bounded linear .... To conclude the proof of theorem 10, it remains to be proven that D(A) is dense.
Corresponding author. Tel.: +33 1 48 02 55 83; fax: +33 1 48 47 30 88. ..... But, prior to this, we prove that (CP) preserves positivity, which will be needed in the a ...
modeling assumptions, we describe the organization process of IF ... Table 1. List of parameters involved in the in vitro model (1) and in the in vivo model (2).
solution y(t) of (0.2) has a period T/r which is close to +oo when r is close to 0. It is a bifur- ... Q*b P, 0) = Q(P, P ~0s 8, P sin 0). w.h ... P, 0) ~0s 0 - p*b4 P, 4 sin wp.
determining whether the simulation ends in (0,0) or in the non-trivial equilibrium. There must be a separatrix ... Trends in Ecology and Evolution 6, 32. ... Experimental demonstrations of Volterra's periodic oscillations in the numbers of animals.
An individual in the quiescent compartment cannot divide as long as it stays in this state. We let t denote time, a age, and we denote the densities of cells in the.
of fast dynamics considered to be linear, conservative in the global variables and in- ducing a ... processes. In comparison, not much has been done up to now in life sciences ...... in Physics, Biology and Economics, Pergamon, Oxford, 1989.
Received 19 January 2004; accepted 1 September 2004 ... political stability of our future world [1]. .... We suppose, taking the same β in both equations,.
