VERA MAURA FERNANDES DE LIMA

VERA MAURA FERNANDES DE LIMA

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Reversibility of excitation waves in brain and heart and the energy of interfacial water
2021 - LIMA, VERA M.F. de; HANKE, WOLFGANG
In this manuscript, we interpret the implications of a discovery we made in 1993 for the understanding of the spread of excitation waves in axon, central gray matter (isolated retina) and heart. We propose that the initial burst of energy dissipation in these waves measured as potentials drops, ionic activities marked changes or optical properties being mostly the effect of dissociated water becoming liquid water and be reversible due to the further on dissociation during the refractory period. We also propose experiments in order to falsify or agree with this conjecture.
Microgravity dependence of excitable biological and physicochemical media
2006 - HANKE, W.; LIMA, V.M.F. de; WIEDEMANN, M.; MEISSNER, K.
Central nervous tissue: an excitable medium. A study using the retinal spreading depression as a tool
2008 - HANKE, WOLFGANG; LIMA, VERA M.F. de
Properties of wave propagation in a gel-type belousov-zhabothinsky reaction under micro-gravity
2009 - HANKE, WOLFGANG; SIEBER, MICHAELA; SPENCER, PATRICK; SCHWERTNER, JURGEN; LIMA, VERA M.F. de
The Belousov–Zhabothinsky (BZ) reaction is a chemical reaction which exhibits spatial as well as temporal pattern formation. Being an excitable medium, it can be influenced by even small external forces. One of these small forces which under ground conditions permanently is given is gravity. The gravity dependence of the BZ-reaction has been investigated in some detail up to now, and it has been found that especially the propagation velocity of waves in thin layers of fluid BZ-medium depends significantly on gravity-amplitude and -orientation. This finding has been mainly assigned to an interaction of gravity with diffusion and convection in the medium at the wave front, and consequently it has been stated that the propagation of waves in gels of BZ-medium is not significantly gravity dependent. We have now done more detailed experiments and have been able to show that also in gels the propagation velocity of BZ-waves is altered by gravity, but less than in fluid systems. Experiments have been performed in a lab centrifuge, a sounding rocket experiment and a parabolic flight mission.