Instabilities of Higher-Order Parametric Solitons. Filamentation versus Coalescence

We investigate stability and dynamics of higher-order solitary waves in quadratic media, which have a central peak and one or more surrounding rings. We show existence of two qualitatively different behaviours. For positive phase mismatch the rings break up into filaments which move radially to initial ring. For sufficient negative mismatches rings are found to coalesce with central peak, forming a single oscillating filament.Comment: 5 pages, 7 figure

On the Properties of Two Pulses Propagating Simultaneously in Different Dispersion Regimes in a Nonlinear Planar Waveguide

Properties of two pulses propagating simultaneously in different dispersion regimes, anomalous and normal, in a Kerr-type planar waveguide are studied in the framework of the nonlinear Schroedinger equation. Catastrophic self-focusing and spatio-temporal splitting of the pulses is investigated. For the limiting case when the dispersive term of the pulse propagating in the normal dispersion regime can be neglected an indication of a possibility of a stable self-trapped propagation of both pulses is obtained.Comment: 18 pages (including 15 eps figures

Glucocortiocoid Treatment of MCMV Infected Newborn Mice Attenuates CNS Inflammation and Limits Deficits in Cerebellar Development

Infection of the developing fetus with human cytomegalovirus (HCMV) is a major cause of central nervous system disease in infants and children; however, mechanism(s) of disease associated with this intrauterine infection remain poorly understood. Utilizing a mouse model of HCMV infection of the developing CNS, we have shown that peripheral inoculation of newborn mice with murine CMV (MCMV) results in CNS infection and developmental abnormalities that recapitulate key features of the human infection. In this model, animals exhibit decreased granule neuron precursor cell (GNPC) proliferation and altered morphogenesis of the cerebellar cortex. Deficits in cerebellar cortical development are symmetric and global even though infection of the CNS results in a non-necrotizing encephalitis characterized by widely scattered foci of virus-infected cells with mononuclear cell infiltrates. These findings suggested that inflammation induced by MCMV infection could underlie deficits in CNS development. We investigated the contribution of host inflammatory responses to abnormal cerebellar development by modulating inflammatory responses in infected mice with glucocorticoids. Treatment of infected animals with glucocorticoids decreased activation of CNS mononuclear cells and expression of inflammatory cytokines (TNF-α, IFN-β and IFNγ) in the CNS while minimally impacting CNS virus replication. Glucocorticoid treatment also limited morphogenic abnormalities and normalized the expression of developmentally regulated genes within the cerebellum. Importantly, GNPC proliferation deficits were normalized in MCMV infected mice following glucocorticoid treatment. Our findings argue that host inflammatory responses to MCMV infection contribute to deficits in CNS development in MCMV infected mice and suggest that similar mechanisms of disease could be responsible for the abnormal CNS development in human infants infected in-utero with HCMV

Multipole mixing ratios in the decay of \u3c sup\u3e 133 \u3c/sup\u3e ba from triple-γ directional correlation measurements

The multipole mixing ratios of the 53.17 and 302.85 keV transitions in 133Cs are measured through γ → γ → γ angular correlation experiments using one NaI(Tl) and two Ge(Li) detectors. Angular correlations for the cascades 276.40 keV → 79.63 keV (θ variable) → 81.00 keV, 276.40 keV → 79.63 keV → 81.00 keV (θ variable), and 53.17 keV → 302.85 keV → 81.00 keV (θ variable) were investigated. The data were analyzed assuming the presently accepted Jπ sequence of 7 2+, 5 2+, 5 2+, 3 2+, and 1 2+ for the ground state and the 81.00, 160.63, 383.82, and 437.00 keV levels in 133Cs, respectively, and taking the 276.40 keV transition to be pure E2, the 81.00 keV transition to be M1 + 2.8% E2, and the 53.17 keV transition to be M1 + 1.0% E2. The multipole mixing ratios σ are determined to be + 0.171-0.050+0.051 for tne 79.63 keV transition and + 0.022 for the 302.85 keV transition. Phases of the mixing ratios of the 81.00, 79.63, and 302.85 keV transitions are adopted after a critical analysis of the data. The present experiment has determined the mixing ratios, along with the phases, free of errors due to angle-dependent Compton distributions of interfering γ-ray cascades. © 1985

The Decay of \u3c sup\u3e 144 \u3c/sup\u3e Ce

The energies and relative intensities of the gamma rays of144Ce have been determined with use of a Ge(Li) detector. The quantum energies are 33.7, 40.8, 53.4, 80.1, 99.8, and 133.5 keV, the associated relative intensities being 2.3+0.2, 5±4, 1.1 ±0.1, 16±1, 0.39±0.04, and 100±6. These data have been interpreted to indicate excited nuclear energy states in 144Pr at 59.03, 80.1, 99.8 and 133.5 keV. © 1970, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved

Decay of Os193 to Ir193

The energies and relative intensities of the γ rays of Os193 (T1/2=32 h) have been measured with a Ge(Li) detector. γ-γ coincidences and β-γ coincidences were studied to obtain energies of nuclear states in Ir193. In all 24 detected γ transitions have been ordered between 11 nuclear energy states. The energies of these transitions are 73, 98, 107, 139, 180, 219, 252, 281, 289, 299, 322, 362, 379, 388, 420, 438, 461, 486, 512, 533, 559, 574, 713, and 874 keV, establishing excited energy states at 73, 139, 180, 362, 438, 461, 559, 680, 713, and 874 keV in the nucleus of Ir193. γ rays corresponding to transition energies of 618, 780, and 830 keV were also observed, but these transitions could not be suitably incorporated into the disintegration scheme. © 1967 The American Physical Society