Horst Thieme
Emeritus Professor, Emeritus College
Emeritus Professor, School of Mathematical and Statistical Sciences

PS A437 TEMPE, AZ 852871804


Long Bio
Horst Thieme works in the fields of differential, difference and integral equations and of dynamical systems. Main areas of application are population dynamics and the dynamics of infectious diseases, with an emphasis on conditions for population persistence and extinction. A recent specific interest is the persistence of structured populations with two sexes and its relation to eigenvalues of harmonic maps. Thieme has authored an undergraduate/graduate text on mathematics in population biology and coauthored an advanced graduate text on population persistence and dynamical systems.
Education
Ph.D. University of Muenster, Germany 1976
Publications
 S.A. Gourley, G. R\"ost, H.R. Thieme,. Uniform persistence in a model for bluetongue dynamics,. SIAM J. Math. Analysis (2014).
 Wen Jin, Horst R. Thieme. Persistence and extinction of diffusing populations with two sexes and short reproductive season. Discrete and Continuous Dynamical System  B (2014).
 Don A. Jones, Hal L. Smith, and Horst R. Thieme. Spread of Viral Infection of Immobilized Bacteria. Networks and Heterogeneous Media (2013).
 H.L. Smith, H.R. Thieme,. Chemostats and epidemics: competition for nutrients or hosts,. Math. Biosciences and Engineering (2013).
 H.L. Smith, H.R. Thieme,. Persistence and global stability for a class of discrete time structured population models,. Discrete & Continuous Dynamical Systems  Series A (DCDSA) (2013).
 D. A. Jones, G. R\"{o}st, H.L. Smith, H. R. Thieme,. Spread of phage infection of bacteria in a petri dish. SIAM J. Applied Math (2012).
 Hal L. Smith. Horst R. Thieme. Persistence of bacteria and phages in a chemostat. J. Math. Biol (2012).
 Hal. L. Smith, H.R. Thieme. A reactiondiffusion system with timedelay modeling virus plaque formation. Canadian Appl. Math. Quart (2011).
 Horst R. Thieme. Global stability of the endemic equilibrium in infinite dimension: Lyapunov functions and positive operators,. J. Differential Eqns (2011).
 Stephen Gourley, Horst R. Thieme, Pauline van den Driessche. Stability and persistence in a model for bluetongue dynamics,. SIAM J. Appl. Math (2011).
 Hal L. Smith, Horst R. Thieme. Dynamical Systems and Population Persistence. (2011).
 Thanate Dhirasakdanon, Horst R. Thieme. Stability of the endemic coexistence equilibrium for one host and two parasites. Mathematical Modelling of Natural Phenomena (2010).
 Horst Thieme, J Voigt. Relatively bounded extensions of generator perturbations. Rocky Mountain Journal of Mathematics (2009).
 Thieme, H. Spectral bound and reproduction number for infinite dimensional population structure and timeheterogeneity. SIAM J. Applied Mathematics (2009).
 Thieme, H., Z. Han, R. Trevino. Species decline and extinction: synergy of infectious disease and Allee effect?. Jounral of Biological Dynamics (2009).
 Thieme, Horst R. Distributed susceptibility: a challenge to persistence theory in infectious disease models. Disc. Cont. Dyn. Sys., B (2009).
 Horst Thieme. Differentiability of convolutions, integrated semigroups of bounded semivariation, and the nonhomogeneous Cauchy problem. J. Evolution Equations (2008).
 Horst Thieme, Abdessamad Tridane, Yang Kuang. An epidemic model with postcontact prophylaxis of distributed length. I. Thresholds for disease persistence and extinction. J. Biological Dynamics (2008).
 Horst Thieme, Karl Hadeler. Monotonicity of the spectral bound under rank 1 perturbations. Journal of Mathematical Biology (2008).
 Thieme, H., A. Tridane, Y. Kuang. An epidemic model with postcontact prophylaxis of distributed length. II. Stability and oscillations if treatment is fully effective,. Mathematical Modelling of Natural Phenomena (2008).
 Martcheva, M., H. Thieme. Infinite ODE systems modeling sizestructured metapopulations, macroparasitic diseases, and prion proliferation. Structured Population Models in Biology and Epidemiology (2008).
 . Special Issue: On the Occasion of the 60th Birthday of Hal L. Smith. (2008).
 Horst Thieme, Stanley Faeth, Karl Hadeler. An apparent paradox of horizontal and vertical disease transmission. Journal of Bioogical Dynamics (2007).
 Horst Thieme, Thanate Dhirasakdanon, Pauline van den Driessche. A sharp threshold for disease persistence in host metapopulations. Journal of Biological Dynamics (2007).
 Horst Thieme, Timothy Lant. Markov transition functions and semigroups of measures. Semigroup Forum (2007).
 Horst Thieme, Timothy Lant. Perturbation of transition functions and a FeynmanKac formula for the incorporation of mortality. Positivity (2007).
 . . Review of: Perturbations of Positive Semigroups with Applications (2007).
 Thieme, H. Pathogen competition and coexistence and the evolution of virulence. Mathematics for Life Science and Medicine (2007).
 Horst Thieme, JÃ„urgen Voigt, M Weber, J Voigt. Stochastic semigroups: their construction by perturbation and approximation. Positivity IV  Theory and Applications (2006).
 Maia Martcheva, Horst Thieme, Thanate Dhirasakdanon. Kolmogorov's differential equations and positive semigroups on first moment sequence spaces. Journal of Mathematical Biology (2006).
 Mats Gyllenberg, Timothy Lant, Horst Thieme. Perturbing evolutionary systems on dual spaces by cumulative outputs. Differential and Integral Equations (2006).
 S Baer, B Koii, Yu Kuznetsov, Horst Thieme. Multiparametric bifurcation analysis of a basic twostage population model. SIAM Journal Applied Mathematics (2006).
 . . Review of: Spatial Deterministic Epidemics (2006).
 Azmy Ackleh, Ben Fitzpatrick, Horst Thieme. Rate distributions and survival of the fittest: a formulation on the space of measures. Disc. Cont. Dyn. Sys. B (2005).
 Jimmy Mopecha, Horst Thieme. Competitive dynamics in a model for river blindness with cross protection. Can. Appl. Math. Quart (2005).
 M Martcheva, Horst Thieme. A Metapopulation Model with Discrete Size Structure. Natural Resource Modeling (2005).
 . Dynamic Aspects of Competition, Adaptation, and Patchiness in Ecology. (2005).
 . Modeling and Control of Natural Resources. (2005).
 . Modeling and Control of Natural Resources, Natural Resource Modeling. (2005).
 Horst Thieme, P Magal. Eventual compactness for semiflows generated by nonlinear agestructured models. Commun. Pure Appl. Anal (2004).
 P Magal, Horst Thieme. Eventual compactness for semiflows generated by nonlinear agestructured models. Discrete and Continuous Dynamical Systems (2004).
 . Semilinear perturbations of Hille Yosida operators. (2004).
 Andre de Roos, Lennart Persson, Horst Thieme. Emergent Allee effects in top predators feeding on structured prey populations. Proc. R. Soc. Lond. B (2003).
 Horst Thieme, XQ Zhao. Asymptotic speeds of spread and traveling waves for integral equations and delayed reactiondiffusion models. J. Differential Equations (2003).
 J Vrabie, Horst Thieme. Relatively compact orbits and compact attractors for a class of nonlinear evolution equations. J. Dynamics Differential Equations (2003).
 Maia Martcheva, Horst Thieme. Progression age enhanced backward bifurcation in an epidemic model with superinfection. J. Mathematical Biology (2003).
 Thieme, Horst Rudolf. Mathematics in Population Biology. (2003).
 Horst Thieme, C CastilloChavez, S Blower, P van den Driessche, D Kirschner, A Yakubu. The transition through stages with arbitrary length distributions, and applications in epidemics. Mathematical Approaches for Emerging and Reemerging Infectious Diseases : Models, Methods and Theory (2002).
 Horst Thieme, Hauke Vobeler. A Stieltjes type convolution for integrated semigroups of strong bounded variation and Lp solutions to the abstract Cauchy problem. Diff. Integral Eqn (2002).
 Horst Thieme, Jinling Yang. An endemic model with variable reinfection rate and application to influenza. Math. Biosci (2002).
 Horst Thieme. Disease extinction and disease persistence in age structured epidemic models. Nonlinear Analysis (2001).
 Horst Thieme, Hal Smith. Stable coexistence and bistability for competitive systems on ordered Banach spaces. J. Diff. Eqn (2001).
 Horst Thieme, O Diekmann, M Gyllenberg, H Huang, M Kirkilionis, J Metz. On the formulation and analysis of general deterministic structured population models.II.Nonlinear theory. J. Math. Biol (2001).
 Horst Thieme, X Zhao. A nonlocal and delayed predatorprey reactiondiffusion model. Nonlinear Analysis RWA 2 (2001).
 Horst Thieme. Balanced exponential growth for perturbed operator semigroups. Advances in Mathematical Sciences and Applications (2000).
 Horst Thieme. Uniform persistence and permanence for nonautonomous semi flows in population biology. Math. Biosci (2000).
 Horst Thieme, O Diekmann, M Gyllenberg. Lack of uniqueness in transport equations with a nonlocal nonlinearity. Math. Models Methods Appl. Sci (2000).
 Horst Thieme, Zhilan Feng. Endemic models with arbitrarily distributed periods of infection I General theory. SIAM J. Appl. Math (2000).
 Horst Thieme, Zhilan Feng. Endemic models with arbitrarily distributed periods of infection.II Fast disease dynamics and permanent recovery. SIAM J. Appl. Math (2000).
 Thanate Dhirasakdanon, Horst R. Thieme. Persistence of vertically transmitted parasite strains which protect against more virulent horizontally transmitted strains,. Modeling and Dynamics of Infectious Diseases (0).
 . . (0).
Research Activity
 Thieme,Horst Rudolf*. Dynamical Systems in HostParasite and Structured Population Models. NSFMPSDMS(8/15/2007  7/31/2011).
 CastilloChavez,Carlos*, Armbruster,Hans Dieter, Greenwood,Priscilla E, Kuang,Yang, Smith,Hal L, Thieme,Horst Rudolf. EMSW21MCTP: Mentorship Through Research: A Model for an Emerging Urban American University. NSFMPS(5/1/2005  7/31/2008).
 Thieme,Horst Rudolf*. DYNAMICAL SYSTEMS IN PARASITEHOST AND STRUCTURED POPULATION MODELS. NSFMPS(7/15/2003  6/30/2007).
 Thieme,Horst Rudolf*. DYNAMICAL SYSTEMS IN STRUCTURED POPULATIONS. NSFMPS(7/1/1998  6/30/2002).
 Thieme,Horst Rudolf*. DYNAMICAL SYSTEMS IN STRUCTURED POPULATIONS. NSFMPS(8/15/1994  7/31/1998).
 Thieme,Horst Rudolf*. STABILITY, OSCILATIONS, & PERSISTENCE IN DIFF. EQUAT. MODELS. NSF(8/1/1991  1/31/1995).
Courses
2024 Fall
Course Number  Course Title 

APM 792  Research 
MAT 792  Research 
APM 799  Dissertation 
2024 Summer
Course Number  Course Title 

MAT 792  Research 
APM 792  Research 
APM 792  Research 
MAT 495  Undergraduate Research 
2024 Spring
Course Number  Course Title 

APM 792  Research 
APM 799  Dissertation 
MAT 792  Research 
MAT 799  Dissertation 
2023 Fall
Course Number  Course Title 

APM 792  Research 
MAT 792  Research 
APM 799  Dissertation 
2023 Summer
Course Number  Course Title 

MAT 792  Research 
APM 792  Research 
APM 792  Research 
MAT 495  Undergraduate Research 
2023 Spring
Course Number  Course Title 

APM 502  Differential Equations II 
APM 792  Research 
APM 799  Dissertation 
MAT 792  Research 
MAT 799  Dissertation 
2022 Fall
Course Number  Course Title 

APM 792  Research 
MAT 792  Research 
APM 503  Applied Analysis 
APM 799  Dissertation 
2022 Summer
Course Number  Course Title 

MAT 792  Research 
APM 792  Research 
APM 792  Research 
MAT 495  Undergraduate Research 
2022 Spring
Course Number  Course Title 

APM 502  Differential Equations II 
APM 792  Research 
APM 799  Dissertation 
MAT 792  Research 
MAT 799  Dissertation 
APM 790  Reading and Conference 
2021 Fall
Course Number  Course Title 

APM 792  Research 
MAT 792  Research 
APM 503  Applied Analysis 
APM 799  Dissertation 
2021 Summer
Course Number  Course Title 

MAT 792  Research 
APM 792  Research 
APM 792  Research 
MAT 495  Undergraduate Research 
2021 Spring
Course Number  Course Title 

APM 502  Differential Equations II 
APM 792  Research 
APM 799  Dissertation 
MAT 792  Research 
MAT 799  Dissertation 
APM 790  Reading and Conference 
2020 Fall
Course Number  Course Title 

APM 792  Research 
MAT 792  Research 
APM 503  Applied Analysis 
APM 799  Dissertation 
MAT 795  Continuing Registration 
MAT 371  Advanced Calculus I 
2020 Summer
Course Number  Course Title 

MAT 792  Research 
APM 792  Research 
APM 792  Research 
MAT 495  Undergraduate Research 
2020 Spring
Course Number  Course Title 

APM 792  Research 
APM 799  Dissertation 
MAT 792  Research 
MAT 799  Dissertation 
APM 790  Reading and Conference 
APM 570  Applied Linear Operators 
2019 Fall
Course Number  Course Title 

MAT 475  Differential Equations 
APM 792  Research 
MAT 792  Research 
APM 503  Applied Analysis 
APM 799  Dissertation 
MAT 795  Continuing Registration 
2019 Summer
Course Number  Course Title 

MAT 792  Research 
APM 792  Research 
APM 792  Research 
Presentations
 Wen Jin, Horst R. Thieme. Twosex populations with short reproduction season that diffuse under Dirichlet boundary conditions". Mathematical Biology Seminar, ASU (Aug 2014).
 Wen Jin, Horst R. Thieme. Twosex populations with short reproduction season that diffuse under Dirichlet boundary conditions". The 10th AIMS Conference on Dynamical Systems, SS Nonlinear elliptic and parabolic problems (Jul 2014).
 G. Fan, H.R. Thieme, H. Zhu. Delay differential systems for tick population dynamics. The 10th AIMS Conference on Dynamical Systems etc, SS Delay equations applied to population dynamics (Jul 2014).
 Wen Jin, H.R. Thieme. The spectral radius of homogeneous orderpreserving maps and the persistence of dispersing twosex populations. Applied Mathematics seminar, University of Muenster, Germany (Jul 2014).
 Wen Jin, H.R. Thieme. The spectral radius of homogeneous orderpreserving maps and the persistence of dispersing twosex populations. Analysis and Probability seminar, University of Leipzig, Germany (May 2014).
 Stephen A. Gourley, Gergely Roest, Horst R Thieme. Dynamics of a differential delay system modeling bluetongue. Math. Biology Seminar, ASU (Sep 2013).
 Horst R. Thieme. Eigenvectors of homogeneous of order preserving maps. Mathematics Seminar, University of Cologne (Jul 2013).
 Horst R. Thieme. Eigenvectors of homogeneous of order preserving maps. Positivity VII, Conference, Leiden, The Netherlands (Jul 2013).
 Stephen A. Gourley, Gergely Roest, Horst R Thieme. Dynamics of a differential delay system modeling bluetongue. Mathematics Seminar, University of Muenster (Jul 2013).
 Stephen A. Gourley, Gergely Roest, Horst R Thieme. Dynamics of a differential delay system modeling bluetongue. Mathematics Seminar, University of Heidelberg (Jul 2013).
 Stephen A. Gourley, Gergely Roest, Horst R Thieme. Dynamics of a differential delay system modeling bluetongue. Mathematics Seminar, University of Dresden (Jun 2013).
 Stephen A. Gourley, Gergely Roest, Horst R Thieme. Dynamics of a differential delay system modeling bluetongue. Meeting of the Society of Math. Biology, Tempe, Arizona (Jun 2013).
 Horst R. Thieme. The basic reproduction number for structured populations as spectral radius of a positive operator. Mathematics and Biology: a Roundtrip in the Light of Suns and Stars, Conference, Leiden, The Netherl (Apr 2013).
 Horst R Thieme. Apparent paradoxes in disease models with horizontal and vertical transmission. Mathematical Biology seminar, ASU (Sep 2012).
 Horst R Thieme. Apparent paradoxes in disease models with horizontal and vertical transmission. Mathematical Biology seminar, University of Szeged, Hungary (Jun 2012).
 Horst R Thieme. Global attractors, stability, and population persistence. Mathematics seminar at the University of Szeged, Hungary (Jun 2012).
 Horst R Thieme. Apparent paradoxes in disease models with horizontal and vertical transmission. Mathematical Biology seminar, University of Trento, Italy (Jun 2012).
 Horst R. Thieme. Global attractors, stability, and population persistence. 5th Butler Conference on Differential Equations and Population Biology, Univ. of Alberta, Edmonton (Jul 2011).
 Horst Thieme. Iterative approximation of the spectral radius of a positive operator. 8th European Conference on Mathematical and Theoretical Biology, SS on Semigroups of Operators in Ma (Jun 2011).
 Horst R Thieme. Apparent paradoxes in disease models with horizontal and vertical transmission". Mathematical Biology seminar, National TsingHua University, Hsinchu, Taiwan (May 2011).
 Horst R. Thieme. Global attractors, stability, and population persistence. Mathematical Biology seminar, National TsingHua University, Hsinchu, Taiwan (May 2011).
 Horst R. Thieme. An epidemic model with postcontact prophylaxis of distributed length. Mathematical Biology seminar, National TsingHua University, Hsinchu, Taiwan (May 2011).
 Horst R. Thieme. Population persistence without a compact attractor. Mathematical Biology seminar, National TsingHua University, Hsinchu, Taiwan (May 2011).
 H.R. Thieme. Global attractors and stability, persistence, and the Laplace transform. 10th Annual Red Raider MiniSymposium (Oct 2010).
 H.R. Thieme. Spectral bound and reproduction number for infinite population structure and timeheterogeneity. Infection Dynamics Days, Utrecht Centre for Infection Dynamics, The Netherlands (Jun 2010).
 Hal L. Smith, H.R. Thieme. Population persistence without a compact attractor. Mathematical Biology seminar, Univ. of Heidelberg, Germany (Jun 2010).
 H.R. Thieme. Differentiability of convolutions, integrated semigroups of bounded semivariation, and the inhomogeneous Cauchy problem. 8th AIMS Conference on Dynamical Systems, special session on Operator Semigroups and Applications, (May 2010).
 H.R. Thieme. Spectral bound and reproduction number for infinite population structure and timeheterogeneity. 8th AIMS Conference on Dynamical Systems,Special session on Evolution Equations and Mathematical Bio (May 2010).
 Thanate Dhirasakdanon, H.R. Thieme. Infectious diseases in amphibians:adults as reservoir for epidemics in larvae. Joint Mathematics Meetings, AMS Special Session on Biomathematics, San Francisco (Jan 2010).
 H.L.Smith, H.R. Thieme. Population Persistence without a compact attractor. Sec. Internat. Conf. on Mathematical Modeling and Analysis of Populations in Biology (Oct 2009).
 Hal L. Smith, H.R. Thieme. Population persistence without a compact attractor. Mathematical Biology Seminar, ASU (Sep 2009).
 H.L. Smith, H.R,Thieme. Global compact attractors and their threeway partition under persistence. Graduate School of Math. Sciences, Univ. of Tokyo, Japan (Sep 2009).
 H.L. Smith, H.R. Thieme. Population persistence without a compact attractor. Annual meewting of the Japanese Society of Mathematical Biology (Sep 2009).
 Thanate Dhirasakdanon, H. R. Thieme. Infectious diseases in amphibians: adults as reservoir for epidemics in larvae. Joint Mathematics Meetings, SIAM Minisymposium Math. Modeling of Natural Resources (Jan 2009).
 Thieme, H. Spectral bound and reproduction number for infinite dimensional population structure and timeheterogeneity. AMS regional meeting in Huntsville, Special session on Mathematical Biology (Oct 2008).
 Thieme, H. Differentiability of convolutions, integrated semigroups of bounded semivariation, and the inhomogeneous Cauchy problem. International Conference on Infinite Dimensional Dynamical Systems (Sep 2008).
 Thieme, H. Distributed susceptibility: a challenge to persistence theory in infectious disease models. Mathematical Tools for MultiScale Biological Processes, Montana State University, Bozeman (Jun 2008).
 Thieme, H. Spectral bound and reproduction number for infinite dimensional population structure and timeheterogeneity. Differential Equations and Applications to Mathematical Biology, Le Havre, France (Jun 2008).
 Thieme, H., A. Tridane, Y. Kuang. An epidemic model with postcontact prohylaxis of distributed length. Workshop on Population Dynamics and Mathematical Biology, Luminy, France (Jun 2008).
 Thieme, Horst. Pathogen competition and coexistence, and the evolution of virulence. AMS regional meeting, Special session on Dynamical Systems and Diffential Equations (May 2008).
 Thieme, Horst , A. Tridane, Y. Kuang. An epidemic model with postcontact prohylaxis of distributed length. 7th AIMS Int. Conf. on Dynamical Systems etc., Special session on Delay Differential Equations (May 2008).
 Thieme, H., T. Dhirasakdanon, Z. Han, R. Trevino. Species decline and extinction: synergy of infectious disease and Allee effect. 7th AIMS Int. Conf. on Dynamical Systems etc., Special session on Dynamical Systems in Biology and (May 2008).
 Thieme, H. Species disappearance: a combination of infectious disease and Allee effect?. Joint Mathematics Meetings, AMS Special Session on Recent Advances in Mathematical Biology, etc (Jan 2008).
 Thieme, Horst. An apparent paradox of horizontal and vertical disease transmission. Dynamical Systems Theory and Its Applications to Biology and Environmental Sciences (Mar 2007).
 Martcheva, Maia, Thieme, Horst, Dhirasakdanon, Thanate. Kolmogorov's differential equations and Markov population chains. Joint Mathematics Meeting, special session on Recent Advances in Mathematical Biology & Epidemiology (Jan 2006).
 Martcheva, Maia, Thieme, Horst. Infinite ODE systems modeling sizestructured metapopulations and macroparasitic diseases. International Workshop on Differential Equations in Mathematical Biology (Jul 2005).
 Martcheva, Maia, Thieme, Horst, Dhirasakdanon, Thanate. Positive semigroups and dynamical systems on sequence spaces, with applications to metapopulations and Markov chains. Positivity IV  Theory and Applications (Jul 2005).
 Faeth, S, Hadeler, K, Thieme, Horst. A paradox of horizontal and vertical disease transmission. Regional AMS meeting, special session on "Extinction, Periodicity, and Chaos in Population and Epi" (Apr 2005).
 Thieme, Horst. Spatially implicit metapopulations with discrete patch size structure. CanadaFrance Meeting of Mathematics, special session on Mathematical Biology (Jul 2004).
 Thieme, Horst. Asymptotic speeds of spread and traveling waves for integral equations and delayed reaction diffusion models. Dynamical Systems and Differential Equations, special session on Mathematical Biology (Jun 2004).
 Thieme, Horst. Asymptotic speeds of spread and traveling waves for integral equations and delayed reaction diffusion models. Third International Conference on the Numerical Solution of Volterra and Delay Equations (May 2004).
 Thieme, Horst. The most basic stagestructured population model with densitydependent per capita transition rate. International Symposium "Dynamical Systems Theory and Its Applications to Biology and Environmental" (Mar 2004).
 Thieme, Horst. Competitive dynamics in a model for onchocerciasis with crossimmunity. Arizona Days
 Martcheva, Maia, Thieme, Horst. Infinite ODE Systems Modeling Sizestructured Metapopulations and Macroparasitic Diseases. Workshop on Spatial Ecology: The Interplay of Theory and Data
 Thieme, Horst. An apparent paradox of horizontal and vertical disease transmission. Colloquium, University of Louisiana
 Thieme, Horst. An apparent paradox of horizontal and vertical disease transmission. First Workshop on the Mathematics of Global Public Health
 Thieme, Horst. An apparent paradox of horizontal and vertical disease transmission. Mathematical Biology Seminar, Ohio State Univ
 Thieme, Horst. An apparent paradox of horizontal and vertical disease transmission. Mathematical Biology seminar, University of Heidelberg, Germany
 Thieme, Horst. An epidemic model with postcontact prophylaxis of distributed length. Mathematical Modeling and Analysis of Populations in Biological Systems
 Thieme, Horst. An epidemic model with postcontact prophylaxis of distributed length. Colloquium, University of Bremen, Germany
 Thieme, Horst. Disease extinction and persistence in spatially heterogeneous hostparasite models. Annual meeting of AMS, Special Session on Recent Advances
Service
 Turkish J of Mathematics, referee (2014  Present)
 American Institute of Mathematical Sciences, special session coorganizer (2010  Present)
 University of Texas at Arlington, reviewer (2009  Present)
 Governance Grievance Committee, member (2007  Present)
 Governance Grievance Committee, member (2007  Present)
 Review Committee (CLAS), member (2007  Present)
 Review Committee (CLAS), member (2007  Present)
 Graduate Committee, (2007  Present)
 Personnel and Budget Committee, member (2014  2014)
 journal Discrete and Continuous Dynamical System  B, associate editor (2014  2014)
 personnel and budget committee, member (2013  2014)
 SIAM J. Applied Mathematics, referee (2013  2014)
 Communications on Pure and Applied Analysis, referee (2013  2013)
 International Journal of Nonlinear Sciences and Numerical Simulation, referee (2013  2013)
 JOURNAL OF DYNAMICS AND DIFFERENTIAL EQUATIONS, Referee (2013  2013)
 Journal of Differential Equations, referee (2013  2013)
 Mathematical Biosciences, referee (2013  2013)
 Nonlinear Analysis A, Referee (2013  2013)
 journal Discrete and Continuous Dynamical System  B, associate editor (2013  2013)
 journal Discrete and Continuous Dynamical System  B, associate editor (2012  2012)
 J. of the European Math. Soc., referee (2012  2012)
 Journal of Differential Equations, referee (2012  2012)
 Journal of Mathematical Biology, referee (2012  2012)
 Journal of Mathematical Sciences of the University of Tokyo, referee (2012  2012)
 Mathematical Reviews (American Math. Soc.), reviewer (2012  2012)
 SIAM journal of Applied Dynamical Systems, referee (2012  2012)
 SIAM journal of Applied Mathematics, referee (2012  2012)
 journal Communications on Pure and Applied Analysis (CPAA), referee (2012  2012)
 journal Mathematical Methods in the Applied Sciences, referee (2012  2012)
 journal Zeitschrift für Analysis und ihre Anwendungen, referee (2012  2012)
 Journal of Biological Dynamics, associate editor (2012  2012)
 Director search committee, member (2012  2012)
 personnel and budget committee, chair (2012  2012)
 Journal of Nonlinear Analysis, Real World Applications, associate editor (2012  2012)
 personnel and budget committee, chair (2011  2011)
 Abstract and Applied Analysis, referee (2011  2011)
 J Math. Biol., referee (2011  2011)
 J. Biol. Systems, referee (2011  2011)
 J. Biological Dynamics, associate editor (2011  2011)
 J. Difference Equations and Appl., referee (2011  2011)
 J. Theor. Biol, referee (2011  2011)
 Math. Biosci. Engin., referee (2011  2011)
 Nonlinear Analysis: Real world applications, associate editor (2011  2011)
 SIAM J. Appl Math., referee (2011  2011)
 SIAM J. Dynamical Systems, referee (2011  2011)
 postdoc hiring subcommittee, member (2011  2011)
 European Soc. for Theor, and Math. Biology and Society of Mathematical Biology, special session coorganizer (2011  2011)
 personnel and budget committee, member (2011  2011)
 Personnel and Budget Committee, member (2010  2011)
 Natural Sciences and Engineering Research Council of Canada, reviewer (2010  2010)
 Bulletin of Mathematical Biology, referee (2010  2010)
 J Mathematical Biology, referee (2010  2010)
 J of Biological Dynamics, associate editor (2010  2010)
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 Nonlinear Analysis: Real world applications, associate editor (2010  2010)
 SIAM J Applied Mathematics, referee (2010  2010)
 SIAM J Dynamical Systems, referee (2010  2010)
 The IMA Journal of Applied Mathematics, referee (2010  2010)
 Turkish J Mathematics, referee (2010  2010)
 Univ. of Texas at Arlington, reviewer (2010  2010)
 Universit\'e Pierre et Marie Curie, reviewer (2010  2010)
 Ad hoc hiring committeee, member (2010  2010)
 search subcommittee, chair (2009  2010)
 Personnel and Budget Committee, member (2009  2010)
 Dynamics of Cont., Discr. & Impulsive Systems, referee (2009  2009)
 International J. of Qualitative Theory of Differential Equations and Applications, referee (2009  2009)
 J Biological Systems, referee (2009  2009)
 J Mathematical Biology, referee (2009  2009)
 J of Biological Dynamics, associate editor (2009  2009)
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 Mathematical Methods in the Applied Sciences, referee (2009  2009)
 Nonlinear Analysis: Real world applications, associate editor (2009  2009)
 SIAM J Applied Mathematics, referee (2009  2009)
 SIAM J Mathematical Analysis, referee (2009  2009)
 promotion subcommitteee, chair (2009  2009)
 American Institute of Mathematical Sciences, referee (2008  2008)
 Banff International Research Station, conference coorganizer (2008  2008)
 Electronic J of Differential Equations, referee (2008  2008)
 J of Biological Dynamics, referee (2008  2008)
 J of Functional Analysis, referee (2008  2008)
 Journal of Biological Dynamics, associate editor (2008  2008)
 Journal of Mathematical Biology, referee (2008  2008)
 Mathematical Biosciences and Engineering, referee (2008  2008)
 Mathematical Modeling of Natural Phenomena, referee (2008  2008)
 Nonlinear Analysis: Real world applications, associate editor (2008  2008)
 SIAM J Applied Mathematics, referee (2008  2008)
 Director Search Committee, member (2007  2008)
 Review Commitee (dept), Chair (2007  2008)
 Graduate Committee, member (2007  2008)
 American Math. Soc., special session coorganizer (2007  2007)
 Bulletin for Mathematical Biology, Referee (2007  2007)
 Canadian Journal of Mathematics, Referee (2007  2007)
 Discrete Continuous Dynamical SystemsA, Referee (2007  2007)
 Journal of Biological Dynamics, associate editor (2007  2007)
 Journal of Biological Dynamics, referee (2007  2007)
 Journal of Mathematical Biology, Referee (2007  2007)
 Mathematical Biosciences, Referee (2007  2007)
 National University of Science and Technology,Bulawayo, Zimbabwe, External Evaluator of Ph.D. diss. (2007  2007)
 Nonlinear Analysis Real World Applications, associate editor (2007  2007)
 Ohia State Univ., promotion letter (2007  2007)
 SIAM Journal of Applied Mathematics, Referee (2007  2007)
 SIAM Journal of Mathematical Analysis, Referee (2007  2007)
 Univ. of Louisiana at Lafayette, letter of recommendation for endowed chair (2007  2007)
 National Research Foundation of South Africa, evaluator of research proposal (2007  2007)
 Awards Committee, member (2007  2007)
 Review Commitee, member (2007  2007)
 Mathematical Biosciences, Referee (2006  2006)
 Review Committee, Member (2006  2006)
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 Canadian Applied Mathematics Quarterly, Referee (2006  2006)
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 University of Alabama, External Evaluator (2005  2005)
 Zeitschrift fuer Angewandte Analysis, Referee (2005  2005)
 Award Committee, member (2004  2005)
 Course Buyout ad hoc committee, chair (2005  2005)
 European Conference for Mathematical and Theoretical Biology, Organizer of a Minisymposium (2005  2005)
 Hiring subcommittee, member (2004  2005)
 Graduate student mentoring committee, member (2003  2005)
 J. Theoretical Biology, Referee (2004  2004)
 NSF, Grant Proposal Reviewer (2004  2004)
 AMS, Lead Special Session Organisor (2003  2004)
 Amer. Math. Socieity, Reviewer (2004)
 Bull. Math. Biol, Referee (2004)
 Conf. Proceedings, Referee (2004)
 Disc. Cont. Dyn. Sys, Referee (2004)
 J. Dyn. Sys. Diff. Eqn, Referee (2004)
 J. Math. Biol, Referee (2004)
 J. appl. Math, Referee (2004)
 Math. Biosci, Referee (2004)
 Math. Medicine and Biol, Referee (2004)
 NSF of Chile, Grant Proposal Reviewer (2004)
 Natural Resource Modeling, Guest Editor (2004)
 Nonlinear Analysis B "Real world applications", Editoral Board (2004)
 Nonlinear Analysis, Real World Appl, Referee (2004)
 Purdue Univ. Indiana, Reviewer (2004)
 SIAM J. Appl. Dyn. Sys, Referee (2004)
 SIAM J. Appl. Math, Referee (2004)
 Springer Verlag, Reviewer (2004)
 Theor. Pop. Biol, Referee (2004)
 Univ. of Miami, External Evaluator (2004)
 Nonlinear Analysis, Real World Applications, Editoral Board (2003)
 Nonlinear Analysis  Real world applications, Editoral Board (2002  2002)
 Nonlinear Analysis RWA, Editoral Board (2002  2002)
 J. Mathematical Analysis Applications, Editoral Board (1995  1995)
 Journal of Mathematical Analysis and Applications, Editoral Board (1995  1995)