Electric impedance spectroscopy techniques have been widely employed to study basic biological processes, and recently explored to estimate postmortem interval (PMI). However, the most-relevant parameter to approximate PMI has not been recognized so far. This study investigated electrical conductivity changes in muscle of 18 sea bass specimens, maintained at different room temperatures (15.
View Article and Find Full Text PDFIn this work we consider a quite general class of two-species hyperbolic reaction-advection-diffusion system with the main aim of elucidating the role played by inertial effects in the dynamics of oscillatory periodic patterns. To this aim, first, we use linear stability analysis techniques to deduce the conditions under which wave (or oscillatory Turing) instability takes place. Then, we apply multiple-scale weakly nonlinear analysis to determine the equation which rules the spatiotemporal evolution of pattern amplitude close to criticality.
View Article and Find Full Text PDFPulmonary hypertension (PH) is a hemodynamic condition characterized by chronically elevated mean pulmonary artery pressure (m-PAP ≥ 25 mmHg) measured at rest by right heart catheterization (RHC). It includes a pre-capillary and a post-capillary form. Pulmonary artery hypertension (PAH) is a pre-capillary form of PH potentially generated by several heterogeneous systemic disorders, whose main hemodynamic change is represented by severely increased pulmonary vascular resistance (PVR).
View Article and Find Full Text PDFTwo hyperbolic reaction-diffusion models are built up in the framework of Extended Thermodynamics in order to describe the spatio-temporal interactions occurring in a two or three compartments aquatic food chain. The first model focuses on the dynamics between phytoplankton and zooplankton, whereas the second one accounts also for the nutrient. In these models, infections and influence of illumination on photosynthesis are neglected.
View Article and Find Full Text PDFPhys Rev E Stat Nonlin Soft Matter Phys
November 2013
A one-dimensional hyperbolic reaction-diffusion model of epidemics is developed to describe the dynamics of diseases spread occurring in an environment where three kinds of individuals mutually interact: the susceptibles, the infectives, and the removed. It is assumed that the disease is transmitted from the infected population to the susceptible one according to a nonlinear convex incidence rate. The model, based upon the framework of extended thermodynamics, removes the unphysical feature of instantaneous diffusive effects, which is typical of parabolic models.
View Article and Find Full Text PDF