Gompertz model with delays and treatment: Mathematical analysis
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1.
Institute of Applied Mathematics and Mechanics, Faculty of Mathematics, Informatics and Mechanics, University of Warsaw, Banacha 2, 02-097 Warsaw
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Received:
01 June 2012
Accepted:
29 June 2018
Published:
01 April 2013
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MSC :
Primary: 34K11, 34K13, 34K18, 34K20, 34K28, 37N25; Secondary: 92B05, 92B25, 92C50.
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In this paper we study the delayed Gompertz model, as a typical model of tumor growth, with a term describing external interference that can reflect a treatment, e.g. chemotherapy. We mainly consider two types of delayed models, the one with the delay introduced in the per capita growth rate (we call it the single delayed model) and the other with the delay introduced in the net growth rate (the double delayed model).We focus on stability and possible stability switches with increasing delay for the positive steady state. Moreover, we study a Hopf bifurcation, including stability of arising periodic solutions for a constant treatment. The analytical results are extended by numerical simulations for a pharmacokinetic treatment function.
Citation: Marek Bodnar, Monika Joanna Piotrowska, Urszula Foryś. Gompertz model with delays and treatment: Mathematical analysis[J]. Mathematical Biosciences and Engineering, 2013, 10(3): 551-563. doi: 10.3934/mbe.2013.10.551
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Abstract
In this paper we study the delayed Gompertz model, as a typical model of tumor growth, with a term describing external interference that can reflect a treatment, e.g. chemotherapy. We mainly consider two types of delayed models, the one with the delay introduced in the per capita growth rate (we call it the single delayed model) and the other with the delay introduced in the net growth rate (the double delayed model).We focus on stability and possible stability switches with increasing delay for the positive steady state. Moreover, we study a Hopf bifurcation, including stability of arising periodic solutions for a constant treatment. The analytical results are extended by numerical simulations for a pharmacokinetic treatment function.
References
[1]
|
Appl. Math. Lett., 13 (2000), 91-95.
|
[2]
|
J. Biol. Sys., 15 (2007), 1-19.
|
[3]
|
Springer-Verlag, New York, 1995.
|
[4]
|
Math. Biosci., 191 (2004), 159-184.
|
[5]
|
Math. Med. Biol., 26 (2009), 63-95.
|
[6]
|
Math. Biosci., 222 (2009), 13-26.
|
[7]
|
Accepted for Math. Pop. Studies.
|
[8]
|
Philos. Trans. R. Soc. London, 115 (1825), 513-585.
|
[9]
|
Cancer Res., 59 (1999), 4770-4775.
|
[10]
|
Springer, New York, 1993.
|
[11]
|
Ann. N. Y. Acad. Sci., 50 (1948), 221-246.
|
[12]
|
SIAM J. Control Optim., 46 (2007), 1052-1079.
|
[13]
|
J. Theor. Biol., 252 (2008), 295-312.
|
[14]
|
Springer, Berlin-Heidelberg, 2007.
|
[15]
|
(submitted).
|
[16]
|
J. Math. Anal. Appl., 382 (2011), 180-203.
|
[17]
|
Math. and Comp. Modelling, 54 (2011), 2183-2198.
|
[18]
|
Math. Biosci. Eng., 8 (2011), 591-603.
|
[19]
|
in "Mathematical Population Dynamics" (eds. O. Arino, D. Axelrod and M. Kimmel), Wuertz, Winnipeg, Canada, (1995), 335-348.
|
-
-
-
-