On a 4-dimensional anti-Kähler manifold, its zero scalar curvature implies that its Weyl curvature vanishes and vice versa. In particular any 4-dimensional anti-Kähler manifold with zero scalar curvature is flat.
In this paper, we introduce a set of methods for processing and analyzing long time series of 3D images representing embryo evolution. The images are obtained by in vivo scanning using a confocal microscope where one of the channels represents the cell nuclei and the other one the cell membranes. Our image processing chain consists of three steps: image filtering, object counting (center detection) and segmentation. The corresponding methods are based on numerical solution of nonlinear PDEs, namely the geodesic mean curvature flow model, flux-based level set center detection and generalized subjective surface equation. All three models have a similar character and therefore can be solved using a common approach. We explain in details our semi-implicit time discretization and finite volume space discretization. This part is concluded by a short description of parallelization of the algorithms. In the part devoted to experiments, we provide the experimental order of convergence of the numerical scheme, the validation of the methods and numerous experiments with the data representing an early developmental stage of a zebrafish embryo.
Modified coal tar pitch was prepared by Friedel-Crafts reaction with 9,10-bis(chloromethyl)anthracene (BCMA). With the aid of IR and Raman’s spectroscopy it was found that BCMA reacted completely with aromatic components of pitch. This modification leads to a significant increase of the carbonisation residue of coal tar pitch without the structure of carbonisate being greatly affected., Jaroslava Svítilová, Vladimír Machovič and František Kolář., and Obsahuje bibliografii