Modelling Tourism in the Galapagos Islands: An Agent-Based Model Approach

Currently tourism is the main driver of change in the Galapagos Islands, affecting the social, terrestrial, and marine sub-systems. Tourism also has direct and indirect consequences for the unique archipelago’s natural habitats and for the human well-being. Describing the mechanisms that drive and affect most the tourism development in Galapagos is a preliminary condition to developing a better understanding of the interaction structure of factors that shape the Galapagos archipelago as a social-ecological complex system. In this paper, we present a first attempt to represent the touristic market in Galapagos trough an Agent Based Model (ABM) of touristic activity, focusing on touristic offers, reservations, and touristic activities. The model is based on an individual-based representation of tourists’ consumption preferences and touristic accommodation offers in the Galapagos Islands. Tourist agents are created to mimic the real world by assigning average characteristics of individuals who visit the Galapagos Archipelago of Ecuador. The accommodation offers (i.e., hotels and cruises) are generated in accordance with actual conditions derived from data collected through field surveys. The model includes a market agent that can change the prices, create and delete accommodation offers following an evolutionary algorithm. We carried out preliminary simulations that show a close agreement between real world data and model outputs. Furthermore we used the model to generate three “what if†scenarios in order to study how emergent patterns in the touristic market in Galapagos are affected by changes in the archipelago environment. In this way we illustrate how the model can be used as a useful tool to help public policy makers to explore the consequences of their decisions

Sintomatologia ansiosa e depressiva em famílias com filhos adolescentes: Qual o papel da diferenciação do self dos pais?

A literatura tem realçado o impacto da história familiar de psicopatologia no desenvolvimento de perturbações emocionais nas gerações mais novas e a associação entre o nível de diferenciação do self e diversos quadros clínicos (e.g., ansiosos e depressivos). Com recurso a um desenho quantitativo transversal e a uma amostra de 104 tríades familiares (mãe, pai e filho/a adolescente), o presente estudo pretende analisar: a associação entre a sintomatologia depressiva e ansiosa de mães e pais e filhos/as adolescentes; e o papel mediador da diferenciação do self das mães e dos pais na relação entre a sintomatologia depressiva e ansiosa de mães e de pais e a sintomatologia depressiva e ansiosa dos/as filhos/as adolescentes. Os resultados mostram que: a sintomatologia depressiva e ansiosa do pai e da mãe são preditoras do nível de diferenciação do self do pai e da mãe; a relação entre a sintomatologia depressiva da mãe e dos/as filhos/as é mediada pela diferenciação do self da mãe; e a sintomatologia ansiosa da mãe é preditora da sintomatologia ansiosa dos/as filhos/as. Apesar de os resultados sugerirem que a mãe tenha também um papel central na transmissão de adversidade aos filhos, apontam para que a sintomatologia ansiosa e depressiva de pais e filhos se associem de formas diferentes. Este estudo tem implicações para a prática clínica e para a literatura na área da psicologia clínica e psicologia da família, ao relevar o impacto da sintomatologia da mãe e do seu nível de diferenciação do self no desenvolvimento de psicopatologia na adolescência.The literature has highlighted the impact of the family psychopathology history on the development of psychopathology in the younger generations and the association between the level of self differentiation and various clinical conditions (e.g., anxiety and depression). Using a quantitative cross-sectional design and a sample of 104 family triads (mother, father and adolescent child), the present study aims to analyze: the association between depressive and anxious symptomatology of mothers and fathers and adolescent children; and the mediating role of the self-differentiation of mothers and fathers in the relationship between the depressive and anxious symptomatology of mothers and fathers and the depressive and anxious symptomatology of the adolescent children. The results show that: the depressive and anxious symptomatology of the father and the mother are predictors of the level of differentiation of the self of the father and the mother; the relationship between the depressive symptomatology of the mother and the child is mediated by the differentiation of the mother's self; and the anxious symptomatology of the mother is a predictor of the anxious symptomatology of the child. Although the results suggest that the mother also has a central role in the transmission of adversity to the children, they point out that the anxious and depressive symptomatology of parents and children associate in different ways. This study has implications for clinical practice and for literature in clinical psychology and family psychology, by highlighting the impact of the mother's symptomatology and mothers’ level of self differentiation in the development of psychopathology in adolescence.Orientação: Ana Priost

Non-local validated parametrization of an agent-based model of local-scale Taenia solium transmission in North-West Peru.

The pork tapeworm, Taenia solium, is the cause of a preventable zoonotic disease, cysticercosis, affecting both pigs and humans. Continued endemic transmission of T. solium is a major contributor of epilepsy and other neurologic morbidity, and the source of important economic losses, in many rural areas of developing countries. Simulation modelling can play an important role in aiding the design and evaluation of strategies to control or even eliminate transmission of the parasite. In this paper, we present a new agent based model of local-scale T. solium transmission and a new, non-local, approach to the model calibration to fit model outputs to observed human taeniasis and pig cysticercosis prevalence simultaneously for several endemic villages. The model fully describes all relevant aspects of T. solium transmission, including the processes of pig and human infection, the spatial distribution of human and pig populations, the production of pork for human consumption, and the movement of humans and pigs in and out in several endemic villages of the northwest of Peru. Despite the high level of uncertainty associated with the empirical measurements of epidemiological data associated with T. solium, the non-local calibrated model parametrization reproduces the observed prevalences with an acceptable precision. It does so not only for the villages used to calibrate the model, but also for villages not included in the calibration process. This important finding demonstrates that the model, including its calibrated parametrization, can be successfully transferred within an endemic region. This will enable future studies to inform the design and optimization of T. solium control interventions in villages where the calibration may be prevented by the limited amount of empirical data, expanding the possible applications to a wider range of settings compared to previous models

Modelling Tourism in the Galapagos Islands: An Agent-Based Model Approach

Currently tourism is the main driver of change in the Galapagos Islands, affecting the social, terrestrial, and marine sub-systems. Tourism also has direct and indirect consequences for the unique archipelago's natural habitats and for the human well-being. Describing the mechanisms that drive and affect most the tourism development in Galapagos is a preliminary condition to developing a better understanding of the interaction structure of factors that shape the Galapagos archipelago as a social-ecological complex system. In this paper, we present a first attempt to represent the touristic market in Galapagos trough an Agent Based Model (ABM) of touristic activity, focusing on touristic offers, reservations, and touristic activities. The model is based on an individual-based representation of tourists' consumption preferences and touristic accommodation offers in the Galapagos Islands. Tourist agents are created to mimic the real world by assigning average characteristics of individuals who visit the Galapagos Archipelago of Ecuador. The accommodation offers (i.e., hotels and cruises) are generated in accordance with actual conditions derived from data collected through field surveys. The model includes a market agent that can change the prices, create and delete accommodation offers following an evolutionary algorithm. We carried out preliminary simulations that show a close agreement between real world data and model outputs. Furthermore we used the model to generate three "what if" scenarios in order to study how emergent patterns in the touristic market in Galapagos are affected by changes in the archipelago environment. In this way we illustrate how the model can be used as a useful tool to help public policy makers to explore the consequences of their decisions

Validation of a Spatial Agent-Based Model for Taenia Solium Transmission (“cystiagent”) Against a Large Prospective Trial of Control Strategies in Northern Peru

Background: The pork tapeworm (Taenia solium) is a parasitic helminth that imposes a major health and economic burden on poor rural populations around the world. As recognized by the World Health Organization, a key barrier for achieving control of T. solium is the lack of an accurate and validated simulation model with which to study transmission and evaluate available control and elimination strategies. CystiAgent is a spatially-explicit agent based model for T. solium that is unique among T. solium models in its ability to represent key spatial and environmental features of transmission and simulate spatially targeted interventions, such as ring strategy. Methods/Principal findings: We validated CystiAgent against results from the Ring Strategy Trial (RST)–a large cluster-randomized trial conducted in northern Peru that evaluated six unique interventions for T. solium control in 23 villages. For the validation, each intervention strategy was replicated in CystiAgent, and the simulated prevalences of human taeniasis, porcine cysticercosis, and porcine seroincidence were compared against prevalence estimates from the trial. Results showed that CystiAgent produced declines in transmission in response to each of the six intervention strategies, but overestimated the effect of interventions in the majority of villages; simulated prevalences for human taenasis and porcine cysticercosis at the end of the trial were a median of 0.53 and 5.0 percentages points less than prevalence observed at the end of the trial, respectively. Conclusions/Significance: The validation of CystiAgent represented an important step towards developing an accurate and reliable T. solium transmission model that can be deployed to fill critical gaps in our understanding of T. solium transmission and control. To improve model accuracy, future versions would benefit from improved data on pig immunity and resistance, field effectiveness of anti-helminthic treatment, and factors driving spatial clustering of T. solium infections including dispersion and contact with T. solium eggs in the environment. Author summary: Neurocysticercosis, caused by the ingestion of Taenia solium eggs, is a major cause of human epilepsy around the world. A wide spectrum of tools to fight T. solium is are now available and include antiparasitic treatment for pigs and humans, porcine vaccines, and sanitation improvements; however, the ideal combination of interventions applied to populations to maximize effectiveness and feasibility is not known. Transmission models are one tool that can be used to compare and evaluate different intervention strategies, but no currently available T. solium models have been tested for accuracy. In this research, we validated our model (“CystiAgent”) by comparing simulations of the model to the results of a large-scale trial testing a variety of T. solium control interventions. The model was calibrated using observed epidemiological data from these villages and evaluated for its ability to reproduce the effect of T. solium control interventions. The validation showed that the model was able to reproduce the baseline levels of disease, but generally overestimated the effect that each intervention would have on transmission. These results will allow us to identify limitations of the current model to improve future versions, and represent a step forward in the creation of a tool to design and evaluate future programs to control and eliminate T. solium

Environmental module parameters.

<p>Environmental module parameters.</p

Simulated relative malaria incidence as calculated inside specific groups of human agents.

<p>Simulated relative malaria incidence as calculated inside specific groups of human agents.</p