Confinement of dynamical chaos expansion in rotifer populations inhabiting heterogeneous environments: an effect of attractor size invariance.

We study the impact of inter-habitat interactions in rotifer populations with intrinsically different types of dynamics: chaotic and regular. For this purpose we use a modified version of the Consensus model. The Consensus model has been shown to be realistic enough to reproduce distinguishing features of the rotifer species dynamics. Being uncoupled, a habitat with chaotic dynamics and habitats with regular oscillations of the rotifer density do not affect each other. Migration of the rotifers between the habitats leads to the invasion of chaos into neighboring habitats, that is chaotic rotifer oscillations replace regular oscillations of the rotifer density in neighboring habitats. The invasion of chaos distorts spatial borders of the rotifer oscillations synchronization clusters. We show that the invasion of chaos is spatially confined. Invariance of the attractor size under transformation of regular oscillations into chaotic ones is demonstrated to be responsible for the chaos confinement.

Invasion of pests resistant to Bt toxins can lead to inherent non-uniqueness in genetically modified Bt-plant dynamics: mathematical modeling.

Genetically modified crops are effective pest management tools for worldwide growers. However, there is a concern that pests may develop resistance to Bt-toxins produced by genetically modified Bt-plants. We study the impact of the Bt-resistant pests on Bt-crops. Furthermore, the dynamics of the Bt-plant-Bt-susceptible insects-Bt-resistant insects system is analysed and it is shown that throughout the insect reproduction period the plant biomass dynamics resulting from invasion of Bt-resistant insects is non-unique. Namely, the chaotic attractor and the limit cycle, which are responsible for the plant and insect biomass dynamics, are shown to coexist. As a result, the Bt-plant-Bt-resistant insect system can manifest either chaotic or regular oscillations of plant and insect biomass depending on spatial patterns resulting from invasion of Bt resistant insects into the Bt plant-Bt susceptible insect system. We show that the non-uniqueness of the system dynamics under unfavorable environmental conditions, such as in the so-called zones of risky agriculture in many developing countries and industrialized countries, can lead to essential decrease in the plant biomass.

Visualization of blood microcirculation parameters in human tissues by time-integrated dynamic speckles analysis.

Statistical analysis of images of time-integrated non-stationary speckle patterns is a tool for diagnostics and imaging of in vivo dynamics of blood microcirculation in superficial layers of tissues and organs. The approach to monitoring blood microcirculation using the contrast analysis of time-averaged speckle images is known as the laser speckle contrast analysis (LASCA) technique. This paper presents a modified version of LASCA, based on the application of a localized light source in combination with the speckle contrast analysis of time-integrated dynamic speckle patterns. This method adds possibilities for the analysis of depth distributions of the blood microcirculation parameters. A theoretical background for the depth-resolved analysis of blood microcirculation parameters is considered here on the basis of the concept of effective optical path distributions for a multiply scattered probe light.