Brazil has become one of the top producers and exporters of food, fibre, and bionergy in the world.The expansion of livestock and soybean production in the Amazon basin appears to be independent of the sugarcane expan...Brazil has become one of the top producers and exporters of food, fibre, and bionergy in the world.The expansion of livestock and soybean production in the Amazon basin appears to be independent of the sugarcane expansion in southeastern Brazil whereas the impact of sugarcane expansion over areas of soybean plantation in previous Cerrado biome is still unknown. However, the expansion of sugarcane production in the state of S?o Paulohas been shown to cause an increase in the local abundance of rodents and result in the emergence of infectious diseases such as hantaviruses and leptospirosis in humans. In addition, with an increase in the use of agrochemicals there will be an increase in euthrophication of watercourses and soil pollution. Considering that S?o Paulo has a population of approximately 40 million people, these local impacts are relevant. Environmental law should be improved and enforced in Brazil to ensure that sugarcane production is not only economically profitable but also environmentally responsible.展开更多
In this paper,five different models for five different kinds of diseases occurring in wildlife populations are introduced.In all models,a logistic growth term is taken into account and the disease is transmitted to th...In this paper,five different models for five different kinds of diseases occurring in wildlife populations are introduced.In all models,a logistic growth term is taken into account and the disease is transmitted to the susceptible population indirectly through an envi-ronment reservoir.The time evolution of these diseases is described together with its spatial propagation.The character of spatial homogeneous equilibria against the uniform and non-uniform perturbations together with the occurrence of Hopf bifurcations are discussed through a linear stability analysis.No Turing instability is observed.The partial differential field equations are also integrated numerically to validate the stability results herein obtained and to extract additional information on the temporal and spatial behavior of the different diseases.展开更多
基金financed by FAPESP-Biota Program(Proc.No.2006/60954-4)CNPq(Proc.No.557872/2008-1).
文摘Brazil has become one of the top producers and exporters of food, fibre, and bionergy in the world.The expansion of livestock and soybean production in the Amazon basin appears to be independent of the sugarcane expansion in southeastern Brazil whereas the impact of sugarcane expansion over areas of soybean plantation in previous Cerrado biome is still unknown. However, the expansion of sugarcane production in the state of S?o Paulohas been shown to cause an increase in the local abundance of rodents and result in the emergence of infectious diseases such as hantaviruses and leptospirosis in humans. In addition, with an increase in the use of agrochemicals there will be an increase in euthrophication of watercourses and soil pollution. Considering that S?o Paulo has a population of approximately 40 million people, these local impacts are relevant. Environmental law should be improved and enforced in Brazil to ensure that sugarcane production is not only economically profitable but also environmentally responsible.
基金This paper was supported by Gruppo Nazionale di Fisica Matematica(GNFM)dell'INdAMby the Italian research Project PRIN 2017 Multiscale phenomena in Continuum Mechanics:singular limits,out-equilibriunh and transitions.
文摘In this paper,five different models for five different kinds of diseases occurring in wildlife populations are introduced.In all models,a logistic growth term is taken into account and the disease is transmitted to the susceptible population indirectly through an envi-ronment reservoir.The time evolution of these diseases is described together with its spatial propagation.The character of spatial homogeneous equilibria against the uniform and non-uniform perturbations together with the occurrence of Hopf bifurcations are discussed through a linear stability analysis.No Turing instability is observed.The partial differential field equations are also integrated numerically to validate the stability results herein obtained and to extract additional information on the temporal and spatial behavior of the different diseases.
