Dynamics of slender monopoles and anti-monopoles in non-Abelian superconductor

Low energy dynamics of magnetic monopoles and anti-monopoles in the U(2) gauge theory is studied in the Higgs (non-Abelian superconducting) phase. The monopoles in this superconducting phase are not spherical but are of slender ellipsoid which are pierced by a vortex string. We investigate scattering of the slender monopole and anti-monopole, and find that they do not always decay into radiation, contrary to our naive intuition. They can repel, make bound states (magnetic mesons) or resonances. Analytical solutions including any number of monopoles and anti-monopoles are obtained in the first non-trivial order of rigid-body approximation. We point out that some part of solutions of slender monopole system in 1+3 dimensions can be mapped exactly onto the sine-Gordon system in 1+1 dimensions. This observation allows us to visualize dynamics of monopole and anti-monopole scattering easily.Comment: 44 pages, 11 figure

Statins prevent pulsatile stretch-induced proliferation of human saphenous vein smooth muscle cells via inhibition of Rho/Rho-kinase pathway

Objective: Pulsatile forces regulate vascular remodeling and trigger vascular diseases such as saphenous vein graft disease. The saphenous vein is exposed to high pressure and pulsatility only after implantation. Statins have been proved to reduce the incidence of vein graft failure. Thus, we investigated the molecular mechanisms of pulsatile stretch-induced saphenous vein smooth muscle cell (SMC) proliferation and potential beneficial effects of statins. Methods and results: Human saphenous vein SMCs were subjected to cyclic stretch (60 cycles/min) in Flex I plates. Cerivastatin and simvastatin significantly prevented stretch-induced increase in SMC proliferation. Stretch induced the membrane accumulation of Rho A and Rho kinase inhibitors (Y-27632 and hydroxyfasudil) and dominant negative Rho A mutant significantly prevented stretch-induced SMC proliferation. In addition, stretch increased the levels of both p44/42 mitogen-activated protein (MAP) kinase and Akt phosphorylation. MAP kinase kinase (MEK)1/2 inhibitor U0126, phosphatidylinositol (PI) 3-kinase inhibitors (wortmaninn and LY294002), and dominant negative Akt mutant significantly prevented stretch-induced SMC proliferation. Cerivastatin significantly prevented stretch-induced membrane accumulation of Rho A. On the other hand, stretch-induced phosphorylation of p44/42 MAP kinase and Akt was not prevented by cerivastatin. Mevalonate restored the preventive effect of cerivasatain on stretch-induced Rho A membrane accumulation. Stretch induced hyperphosphorylation of retinoblastoma protein (pRb), which was prevented by cerivastatin and the Rho kinase inhibitors. Conclusion: Statins prevent stretch-induced saphenous vein SMC proliferation via inhibition of the Rho/Rho-kinase pathway. This may explain the beneficial effects of this class of drug, especially for patients after coronary artery bypass graftin

Hyper-Kahler Sigma Models on (Co)tangent Bundles with SO(n) isometry

We construct N=2 supersymmetric nonlinear sigma models whose target spaces are tangent as well as cotangent bundles over the quadric surface Q^{n-2} = SO(n)/[SO(n-2)\times U(1)]. We use the projective superspace framework, which is an off-shell formalism of N=2 supersymmetry.Comment: 33 pages, 1 figure, typos corrected, to appear in Nucl. Phys.

Craniocervical junction abnormalities with atlantoaxial subluxation caused by ventral subluxation of C2 in a dog

Craniocervical junction abnormalities with atlantoaxial subluxation caused by ventral subluxation of C2 were diagnosed in a 6-month-old female Pomeranian with tetraplegia as a clinical sign. Lateral survey radiography of the neck with flexion revealed  atlantoaxial subluxation with ventral subluxation of C2. Computed tomography revealed absence of dens and atlanto-occipital overlapping. Magnetic resonance imaging showed compression of the spinal cord and indentation of caudal cerebellum. The diagnosis was Chiari-like malformation, atlantoaxial subluxation with ventral displacement of C2,  atlanto-occipital overlapping, and syringomyelia. The dog underwent foramen magnum decompression, dorsal laminectomy of C1, and ventral fixation of the atlantoaxial joint. Soon after the operation, voluntary movements of the legs were recovered. Finally, the dog could stand and walk without assistance. The dog had complicated malformations at the craniocervical junction but foramen magnum decompression and dorsal  laminectomy for Chiari-like malformation, and ventral fixation for atlantoaxial  subluxation resulted in an excellent clinical outcome.Keywords: Atlantoaxial subluxation, Atlanto-occipital overlapping, Chiari-like  malformation, Craniocervical junction abnormalities, Foramen magnum  decompression