Non-orthogonality and κ\kappa-dependence eccentricity of polarized electromagnetic waves in CPT-even Lorentz violation

We discuss the modified Maxwell action of a $K_{F}$-type Lorentz symmetry breaking theory and present a solution of Maxwell equations derived in the cases of linear and elliptically polarized electromagnetic waves in the vacuum of CPT-even Lorentz violation. We show in this case the Lorentz violation has the effect of changing the amplitude of one component of the magnetic field, while leaving the electric field unchanged, leading to non-orthogonal propagation of eletromagnetic fields and dependence of the eccentricity on $\kappa$-term. Further, we exhibit numerically the consequences of this effect in the cases of linear and elliptical polarization, in particular, the regimes of non-orthogonality of the electromagnetic wave fields and the eccentricity of the elliptical polarization of the magnetic field with dependence on the $\kappa$-term.Comment: 16 pages, 12 figure

Drosophila protein kinase N (Pkn) is a negative regulator of actin-myosin activity during oogenesis

Nurse cell dumping is an actin-myosin based process, where 15 nurse cells of a given egg chamber contract and transfer their cytoplasmic content through the ring canals into the growing oocyte. We isolated two mutant alleles of protein kinase N (pkn) and showed that Pkn negatively-regulates activation of the actin-myosin cytoskeleton during the onset of dumping. Using live-cell imaging analysis we observed that nurse cell dumping rates sharply increase during the onset of fast dumping. Such rate increase was severely impaired in pkn mutant nurse cells due to excessive nurse cell actin-myosin activity and/or loss of tissue integrity. Our work demonstrates that the transition between slow and fast dumping is a discrete event, with at least a five to six-fold dumping rate increase. We show that Pkn negatively regulates nurse cell actin-myosin activity. This is likely to be important for directional cytoplasmic flow. We propose Pim provides a negative feedback loop to help avoid excessive contractility after local activation of Rho GTPase. (C) 2014 Elsevier Inc. All rights reserved.National Portuguese Funding through Grants FCT-Fundacao para Ciencia e Tecnologia [PTDC/SAU-BID/111796/2009, PTDC/BIA-BCM/111822/2009, PTDC/BBB-BQB/0712/2012, PEst-OE/EQB/LA0023/2013]; Fundacao para Ciencia e Tecnologia [SFRH/BD/37587/2007]info:eu-repo/semantics/publishedVersio