Periodic modes in a mathematical model of testosterone regulation
نویسندگان
چکیده
Periodic solutions of a recently suggested parsimonious mathematical model of pulse-modulated regulation of non-basal testosterone secretion in the male are studied. The model is of third order, reflecting the three most significant hormones in the regulation loop, but yet is shown to be capable of sustaining periodic solutions with one or two pulses of gonadotropin-releasing hormone on each period. Lack of stable periodic solutions is otherwise a main shortcoming of existing low order hormone regulation models. Copyright c © 2007 IFAC
منابع مشابه
Mathematical model of non-basal testosterone regulation in the male by pulse modulated feedback
A parsimonious mathematical model of pulse modulated regulation of non-basal testosterone secretion in the male is developed. The model is of third differential order, reflecting the three most significant hormones in the regulation loop, but is yet shown to be capable of sustaining periodic solutions with one or two pulses of gonadotropin-releasing hormone (GnRH) on each period. Lack of stable...
متن کاملAnalysis of unstable modes distinguishes mathematical models of flagellar motion
The mechanisms underlying the coordinated beating of cilia and flagella remain incompletely understood despite the fundamental importance of these organelles. The axoneme (the cytoskeletal structure of cilia and flagella) consists of microtubule doublets connected by passive and active elements. The motor protein dynein is known to drive active bending, but dynein activity must be regulated to ...
متن کاملCorrection: Analysis of unstable modes distinguishes mathematical models of flagellar motion.
The mechanisms underlying the coordinated beating of cilia and flagella remain incompletely understood despite the fundamental importance of these organelles. The axoneme (the cytoskeletal structure of cilia and flagella) consists of microtubule doublets connected by passive and active elements. The motor protein dynein is known to drive active bending, but dynein activity must be regulated to ...
متن کاملBifurcations in a mathematical model of non-basal testosterone production
A recently proposed by the authors impulsive mathematical model of non-basal testosterone secretion of the hypothalamic-pituitary-testicular axis in the male is considered. Conditions for existence of periodic solutions in the model, their parametrization and stability are studied. Parameter bifurcations which lead to periodic oscillations of hormone levels with one or two pulses of gonadotropi...
متن کاملDevelopment of Forward-wave Directional Couplers Loaded by Periodic Shunt Shorted Stubs
In this paper a new procedure for designing forward-wave directional couplers using periodic shunt short circuited stubs is proposed. A new type of cell using these stubs, which enlarge the phase difference between even- and odd modes of a uniform microstrip coupled line is introduced. Using the equivalent circuit model for even- and odd-modes of the proposed cell, the elements of the ABCD tra...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 2007