Many epidemic models are written in terms of ordinary differential equations (ODE). This approach Basket Blazer Bebe relies on the homogeneous mixing assumption; that is, the topological structure of the contact network established by the individuals of the host population is not relevant to predict the spread of a pathogen in this population. Here, we propose an epidemic model based on ODE to study the propagation of contagious diseases conferring no immunity. The state variables of this model are the percentages of susceptible individuals, infectious individuals and empty space. We show that this dynamical system can experience transcritical and Hopf bifurcations. Then, we employ this model to evaluate the validity of the homogeneous mixing assumption by using real data related to the transmission of gonorrhea, hepatitis C virus, human immunodeficiency virus, and obesity.
The seismic energy concentration within the volcanic chain of the Aegean Sea is calculated. The definition of the concentration of earthquake energy is briefly treated mathematically. According to the results, in the lower half of the part of the lithosphere under the respective volcanoes there exist cylinder-like volumes, with a radius of at least 25 km, in which the rigidity of the material is presumably too low for the slow accumulation of mechanical strains. These cylindric aseismic domains are to be found beneath all of the volcanoes considered, and can be regarded as the place of deep volcanic vents (“translithospheric chimneys”), corresponding to the theory Blazer Nike Femme of Ninkovich and Hays (1971) as Acheter Nike Blazer Vintage Femme well as that of Gorshkov (1969). As regards the upper half of the lithosphere, the continuation of these translithospheric volcanic vents is there much narrower.
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