Symmetry Breaking and Bifurcations in the Periodic Orbit Theory; 1, Elliptic Billiard

We derive an analytical trace formula for the level density of the two-dimensional elliptic billiard using an improved stationary phase method. The result is a continuous function of the deformation parameter (eccentricity) through all bifurcation points of the short diameter orbit and its repetitions, and possesses the correct limit of the circular billiard at zero eccentricity. Away from the circular limit and the bifurcations, it reduces to the usual (extended) Gutzwiller trace formula which for the leading-order families of periodic orbits is identical to the result of Berry and Tabor. We show that the circular disk limit of the diameter-orbit contribution is also reached through contributions from closed (periodic and non-periodic) orbits of hyperbolic type with an even number of reflections from the boundary. We obtain the Maslov indices depending on deformation and energy in terms of the phases of the complex error and Airy functions. We find enhancement of the amplitudes near the common bifurcation points of both short-diameter and hyperbolic orbits. The calculated semiclassical level densities and shell energies are in good agreement with the quantum mechanical ones

Visual field defects of optic neuritis in neuromyelitis optica compared with multiple sclerosis

<p>Abstract</p> <p>Background</p> <p>Neuromyelitis optica (NMO) is an inflammatory demyelinating disease that predominantly affects the optic nerves and the spinal cord, and is possibly mediated by an immune mechanism distinct from that of multiple sclerosis (MS). Central scotoma is recognized as a characteristic visual field defect pattern of optic neuritis (ON), however, the differing pathogenic mechanisms of NMO and MS may result in different patterns of visual field defects for ON.</p> <p>Methods</p> <p>Medical records of 15 patients with NMO and 20 patients with MS having ON were retrospectively analyzed. A thorough systemic and neurological examination was performed for evaluating ON. The total number of relapses of ON and visual fields was investigated. Visual fields were obtained by Goldmann perimeter with each ON relapse.</p> <p>Results</p> <p>All MS patients experienced central scotoma, with 90% of them showing central scotoma with every ON relapse. However, 53% of NMO patients showed central scotoma with every ON relapse (p = 0.022), and the remaining 47% of patients experienced non-central scotoma (altitudinal, quadrant, three quadrant, hemianopia, and bitemporal hemianopia). Thirteen percent of NMO patients did not experience central scotoma during their disease course. Altitudinal hemianopia was the most frequent non-central scotoma pattern in NMO.</p> <p>Conclusions</p> <p>NMO patients showed higher incidence of non-central scotoma than MS, and altitudinal hemianopia may be characteristic of ON occurring in NMO. As altitudinal hemianopia is highly characteristic of ischemic optic neuropathy, we suggest that an ischemic mechanism mediated by anti-aquaporin-4 antibody may play a role in ON in NMO patients.</p

Clinical and MRI features of Japanese MS patients with NMO-IgG

ABSTRACT Background: NMO-IgG is a disease-specific serum marker autoantibody of neuromyelitis optica (NMO) and may distinguish NMO from multiple sclerosis (MS). NMO-IgG has also been frequently detected in Japanese patients with the optic-spinal form of MS (OSMS) suggesting that NMO and OSMS may be the same entity

Development of Co-Based Amorphous Core for Untuned Broadband RF Cavity

We have developed a cobalt-based amorphous core as a new magnetic-alloy(MA) core for the loaded RF cavity. Because of its permeability found to be approximately twice as high as that of FINEMET, this MA core is an excellent candidate for constructing acompact broadband RF cavity with less power consumption. In this report, we present our recent studies of the Co-based amorphous cores physical properties, performance, and development.Particle Accelerator Conference 200

Ames, Oakes Nov. 16, 1923 [to C.H. Lankester]

A compact cavity for acceleration has been developed with cobalt-based amorphous cores. This core has high permeability that enables the cavity length to be madeshort, and its low Q-value of about 0.5 permits an RF system without tuning control of the cavity. In the frequency range from 0.4 to 8 MHz, an accelerationvoltage of more than 4 kV can be obtained with a total input RF power of 8 kW. In this paper the structure of the cavity, the obtained core impedance, and theirperformances under high-power test are presented