Dottorato in Matematica 28° ciclo SEMINARIO DI DOTTORATO Mercoledì 7 ottobre 2015 ore 10:10 (Aula Seminari di Matematica) Valentina Clamer MCMC METHODS APPLIED TO EPIDEMIC OUTBREAKS IN SCHOOLS AND DYNAMICS OF HOST-PARASITOID INTERACTION AND COEXISTENCE OF DIFFERENT HOSTS In the first part of this thesis, we develop a discrete-time SIR model to estimate the probabilities of transmission between children of the same class, of the same grade but different class and of different grades. The motivations for this analysis come from the attention that was given to the A/H1N1 2009 flu pandemic that has made it possible to collect detailed data on the epidemic spread in more typical contexts, especially schools that are well known to represent hot spots for epidemic spread. Data on infection during that pandemic were collected also among students of two primary schools in Trento (Italy). Although the data obtained were not detailed, we show how their analysis yields estimates of transmission rates within class, grade or school, that appear consistent between the two schools and with our general understanding. Since the data are only partially observable, the by now classical approach of Markov Chain Monte Carlo Methods is followed to make inference about the missing data and the unknown parameters. In the second part, we present a model in which one parasitoid species attacks two host species, extending the overlapping generation model presented by Murdoch et al. (1987). Conditions for coexistence can be explicitly found when the interaction between each host and the parasitoid results in equilibrium coexistence. We investigate, through numerical bifurcation, whether parameter values leading to periodic solutions make coexistence Dipartimento di Matematica Via Sommarive, 14 38123 Povo (TN), Italy Tel. +39 0461 281625 Fax +39 0461 281624 mail: [email protected] easier. Beyond theoretical issues, a potential application of the problem concerns the response of native Drosophila parasitoids to the recent invasion of the orchard pest Drosophila suzukii as we can see from the data collected by the Edmund Mach Foundation in San Michele (Italy). Relatore: Andrea Pugliese