1,784 research outputs found
Periodic and Localized Solutions of the Long Wave-Short Wave Resonance Interaction Equation
In this paper, we investigate the (2+1) dimensional long wave-short wave
resonance interaction (LSRI) equation and show that it possess the Painlev\'e
property. We then solve the LSRI equation using Painlev\'e truncation approach
through which we are able to construct solution in terms of three arbitrary
functions. Utilizing the arbitrary functions present in the solution, we have
generated a wide class of elliptic function periodic wave solutions and
exponentially localized solutions such as dromions, multidromions, instantons,
multi-instantons and bounded solitary wave solutions.Comment: 13 pages, 6 figure
Temperature Dependence of Pair Correlations in Nuclei in the Iron-Region
We use the shell model Monte Carlo approach to study thermal properties and
pair correlations in Fe and in Cr. The calculations are
performed with the modified Kuo-Brown interaction in the complete model
space. We find generally that the proton-proton and neutron-neutron
pairing correlations, which dominate the ground state properties of even-even
nuclei, vanish at temperatures around 1 MeV. This pairing phase transition is
accompanied by a rapid increase in the moment of inertia and a partial
unquenching of the M1 strength. We find that the M1 strength totally unquenches
at higher temperatures, related to the vanishing of isoscalar proton-neutron
correlations, which persist to higher temperatures than the pairing between
like nucleons. The Gamow-Teller strength is also correlated to the isoscalar
proton-neutron pairing and hence also unquenches at a temperature larger than
that of the pairing phase transition.Comment: RevTeX and ps figure
Parallel hybrid textures of lepton mass matrices
We analyse the parallel hybrid texture structures in the charged lepton and
the neutrino sector. These parallel hybrid texture structures have physical
implications as they cannot be obtained from arbitrary lepton mass matrices
through weak basis transformations. The total sixty parallel hybrid texture
structures can be grouped into twelve classes, and all the hybrid textures in
the same class have identical physical implications. We examine all the twelve
classes under the assumption of non-factorizable phases in the neutrino mass
matrix. Five out of the total twelve classes are found to be phenomenologically
disallowed. We study the phenomenological implications of the allowed classes
for 1-3 mixing angle, Majorana and Dirac-type violating phases.
Interesting constraints on effective Majorana mass are obtained for all the
allowed classes.Comment: Physical Review D (To appear
GM1 Ganglioside Modifies α-Synuclein Toxicity and is Neuroprotective in a Rat α-Synuclein Model of Parkinson\u27s Disease.
While GM1 may interact with α-synuclein in vitro to inhibit aggregation, the ability of GM1 to protect against α-synuclein toxicity in vivo has not been investigated. We used targeted adeno-associated viral vector (AAV) overexpression of human mutant α-synuclein (A53T) in the rat substantia nigra (SN) to produce degeneration of SN dopamine neurons, loss of striatal dopamine levels, and behavioral impairment. Some animals received daily GM1 ganglioside administration for 6 weeks, beginning 24 hours after AAV-A53T administration or delayed start GM1 administration for 5 weeks beginning 3 weeks after AAV-A53T administration. Both types of GM1 administration protected against loss of SN dopamine neurons and striatal dopamine levels, reduced α-synuclein aggregation, and delayed start administration of GM1 reversed early appearing behavioral deficits. These results extend prior positive results in MPTP models, are consistent with the results of a small clinical study of GM1 in PD patients that showed slowing of symptom progression with chronic use, and argue for the continued refinement and development of GM1 as a potential disease modifying therapy for PD
Three-dimensional modeling of the neutron spectrum to infer plasma conditions in cryogenic inertial confinement fusion implosions
Neutron-based diagnostics are typically used to infer compressed core conditions such as areal density and ion temperature in deuterium–tritium (D–T) inertial confinement fusion (ICF) implosions. Asymmetries in the observed neutron-related quantities are important to understanding failure modes in these implosions. Neutrons from fusion reactions and their subsequent interactions including elastic scattering and neutron-induced deuteron breakup reactions are tracked to create spectra. It is shown that background subtraction is important for inferring areal density from backscattered neutrons and is less important for the forward-scattered neutrons. A three-dimensional hydrodynamic simulation of a cryogenic implosion on the OMEGA Laser System [Boehly et al., Opt. Commun. 133, 495 (1997)] using the hydrodynamic code HYDRA [Marinak et al., Phys. Plasmas 8, 2275 (2001)] is post-processed using the tracking code IRIS3D. It is shown that different parts of the neutron spectrum from the view can be mapped into different regions of the implosion, enabling an inference of an areal-density map. It is also shown that the average areal-density and an areal-density map of the compressed target can be reconstructed with a finite number of detectors placed around the target chamber. Ion temperatures are inferred from the width of the D–D and D–T fusion neutron spectra. Backgrounds can significantly alter the inferred ion temperatures from the D–D reaction, whereas they insignificantly influence the inferred D–T ion temperatures for the areal densities typical of OMEGA implosions. Asymmetries resulting in fluid flow in the core are shown to influence the absolute inferred ion temperatures from both reactions, although relative inferred values continue to reflect the underlying asymmetry pattern. The work presented here is part of the wide range of the first set of studies performed with IRIS3D. This code will continue to be used for post-processing detailed hydrodynamic simulations and interpreting observed neutron spectra in ICF implosions
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