7 research outputs found
Irreducible Killing Tensors from Third Rank Killing-Yano Tensors
We investigate higher rank Killing-Yano tensors showing that third rank
Killing-Yano tensors are not always trivial objects being possible to construct
irreducible Killing tensors from them. We give as an example the Kimura IIC
metric were from two rank Killing-Yano tensors we obtain a reducible Killing
tensor and from third rank Killing-Yano tensors we obtain three Killing
tensors, one reducible and two irreducible.Comment: 10 page
Microglial morphology in the somatosensory cortex across lifespan. A quantitative study
Background: Microglia are long-lived cells that constantly monitor their
microenvironment. To accomplish this task, they constantly change their morphology both in the short and long term under physiological conditions. This
makes the process of quantifying physiological microglial morphology difficult.
Results: By using a semi-manual and a semi-automatic method to assess fine
changes in cortical microglia morphology, we were able to quantify microglia
changes in number, surveillance and branch tree starting from the fifth postnatal day to 2 years of life. We were able to identify a fluctuating behavior of most
analyzed parameters characterized by a rapid cellular maturation, followed by
a long period of relative stable morphology during the adult life with a final
convergence to an aged phenotype. Detailed cellular arborization analysis
revealed age-induced differences in microglia morphology, with mean branch
length and the number of terminal processes changing constantly over time.
Conclusions: Our study provides insight into microglia morphology changes
across lifespan under physiological conditions. We were able to highlight, that
due to the dynamic nature of microglia several morphological parameters are
needed to establish the physiological state of these cells
Dirac Spinor Waves and Solitons in Anisotropic Taub-NUT Spaces
We apply a new general method of anholonomic frames with associated nonlinear
connection structure to construct new classes of exact solutions of
Einstein-Dirac equations in five dimensional (5D)gravity. Such solutions are
parametrized by off-diagonal metrics in coordinate (holonomic) bases, or,
equivalently, by diagonal metrics given with respect to some anholonomic frames
(pentads, or funfbiends, satisfing corresponding constraint relations). We
consider two possibilities of generalization of the Taub NUT metric in order to
obtain vacuum solutions of 5D Einsitein equations with effective
renormalization of constants having distinguished anisotropies on an angular
parameter or on extra dimension coordinate. The constructions are extended to
solutions describing self-consistent propagations of 3D Dirac wave packets in
5D anisotropic Taub NUT spacetimes. We show that such anisotropic
configurations of spinor matter can induce gravitational 3D solitons being
solutions of Kadomtsev-Petviashvili or of sine-Gordon equations.Comment: revtex, 16 pages, version 4, affiliation changed, accepted to CQ