https://repositorio.utem.cl/handle/30081993/1361 2026-04-27T18:57:24Z https://repositorio.utem.cl/handle/30081993/1372 Modelos Metapoblacionales y su importancia en ecología: más allá de Richard Levins. Bustamante, Ramiro O. The study of metapopulations has played a fundamental role in our understanding Spatial Ecology, Metacommunities and Biogeography, among other areas. Richard Levins, defined the metapopulation as a system of local populations existing in an heterogeneous landscape, connected to each other by the movement of individuals. He also formulated a first model based on differential equations, to investigate the conditions under which a metapopulation can persist indefinitely. The Levins´s model highlights the importance of the movement of individuals between patches to ensure the persistence of the metapopulations, an idea that has permeated species conservation policies. Other models based on the Levins´s model have incorporated other ecological factors, among which the rain effect of propagules and the rescue effect stand out. In this essay, I review these models, study their dynamic properties and comment on some of their theoretical and applied implications. Pág. 21 – 25, gráficos, fórmulas. 2022-04-01T00:00:00Z https://repositorio.utem.cl/handle/30081993/1371 A metapopulations epidemic model and its measures for potential mitigation. Veloz, Tomas Strategies attempting to reduce the impact of Covid19 attempted harnessing available geo-spatial, demographic, and behavioural data. Such data has shown to be extremely useful for identifying drivers behind the transmission of the disease. In this article, we develop a toy model emulating the spatial and demographic features of Santiago de Chile, quantify the presence and interaction among different groups in the different spaces defined by the model, and show that effects of the infection dynamics are hidden in the infection data that is usually fitted. In partiucular, we show that the distribution of contagion rates among different sectors distributes as a power-law regardless of the pandemic situation (outbreak vs full spread), and that the power-law distribution strongly depends on a social segregation. Pág. 13 – 19, gráficos, fórmulas, imágenes. 2022-04-01T00:00:00Z https://repositorio.utem.cl/handle/30081993/1370 Un modelo de población animal afectada por una enfermedad tipo SIR y fragmentación de hábitat. Valle Salamanca, Rodrigo Del; Solís Ganga, M. Eugenia; Chiu, Kuo-Shou This work presents a mathematical model that assumes the existence of an animal population that, from an epidemiological point of view, is being affected by an infectious disease of the SIR type and, from an ecological perspective, its habitat is in a gradual process of fragmentation. We make a first approximation to its dynamic behavior through graphical representations of numerical simulations. Pág. 7 – 12, gráficos y fórmulas. 2022-04-01T00:00:00Z https://repositorio.utem.cl/handle/30081993/1369 Metastatic papillary thyroid cancer under treatment with different I-131 protocols: a mathematical model. Antunes, Maria Eliza; Rodrigues da Silva, Izabel Cristina; Martins de Morais, Rafael; Gomes da Silva, Jairo; de Arruda Mancera, Paulo Fernando A mathematical model was used to study numerically, the metastatic papillary thyroid cancer (PTC) response to protocols of treatment with radioiodine I-131 (RAI), considering different values for the RAI efficiency ratio. Besides that, scenarios with decreasing amounts of doses, and a higher dose first, followed by smaller ones, were also proposed. In some simulations the number of tumor cells did not decrease, indicating a resistance against RAI treatment conditions. The failure may mean a poorly structured treatment protocol regarding the type of therapy, doses, application intervals, or any of their combinations. RAI treatment scenarios with alternating dosages, starting with a higher dose followed by smaller ones, presented a possible successful treatment response, i.e., tumor elimination. This variation is not common in clinical practice, but the scenario sheds light on new possible forms of treatment. Through numerical simulations with the ordinary differential equations system, it was shown that mathematical models are important tools in the study of thyroid cancer and could assist in determining the most suitable treatment protocols for metastatic PTC. Pág. 1 - 6, gráficos y fórmulas. 2022-04-01T00:00:00Z