Narrow Results

We construct numerical aneurysm models arisen from both straight and curved arteries, under the hypothesis that high local wall shear stress larger than a certain threshold value will lead to a linear decrease in the wall mechanical properties. Development of aneurysm is observed in both the straight and curved models. In the straight model, the growth of aneurysm is small and only at the distal neck region, and the aneurysm stops growing after several steps. In contrast, in the curved model, the aneurysm continues to grow in height and width. Our computer simulation study shows that even if the wall shear stress inside an aneurysm is low, aneurysm development can occur due to degeneration of the wall distal and proximal to the aneurysm. The interaction between the hemodynamic change (caused by the shape change) and the wall degeneration is key to the development of aneurysms. Our method demonstrates the potential utility of rule-based numerical methods in the investigation of developmental biology of cardiovascular diseases.

We discuss the most general Finsler spacetime geometry obeying the cosmological symmetry group SO(4). On this background geometry we derive the equations of motion for the most general kinetic fluid obeying the same cosmological symmetry. For this purpose we propose a set of coordinates on the tangent bundle of the spacetime manifold which greatly simplifies the cosmological symmetry generators.

The paper deals with the mathematical model of movement of a body in a viscous medium. The problem of control for a solid body moving in the viscous medium from initial position to the given one is considered. Movement occurs at Reynolds's greater numbers that generates effects of failure of the laminar boundary layer, caused by return difference of a gradient of pressure. Thus behind a body the vortex path is formed. The frequency of failure of whirlwinds is expressed in the form of the dimensionless parameter. Asymmetrical formation of whirlwinds leads to occurrence periodic cross-section to speed of power influences on a body. Oscillatory movements, especially as a result develop if the frequency of formation of whirlwinds comes nearer to own frequency of fluctuations of a body.

It has been difficult to predict various classes of boom-and-bust economic cycles and these cyclic catastrophes systematically, because they are related to several biological phenomena. In this report, we will show that our theory on the morphogenetic process and the brain with a rhythm of about seven beats can explain several economic system cycles, because different types of economic cycles are about seven times the length of the fundamental production cycles or durable periods. We will also outline the spatial structure underlying economic systems on the basis of the fluid dynamic theory that describes subatomic systems, biological systems, human network systems, and stars.