Dynamics of quasi-one-dimensional bright and vortex solitons of a dipolar Bose-Einstein condensate with repulsive atomic interaction

By numerical and variational analysis of the three-dimensional Gross-Pitaevskii equation we study the formation and dynamics of bright and vortex-bright solitons in a cigar-shaped dipolar Bose-Einstein condensate for large repulsive atomic interactions. Phase diagram showing the region of stability of the solitons is obtained. We also study the dynamics of breathing oscillation of the solitons as well as the collision dynamics of two solitons at large velocities. Two solitons placed side-by-side at rest coalesce to form a stable bound soliton molecule due to dipolar attraction.Comment: To obtain the included video clips S1, S2, S3 and S4, please download sourc

The appearance of non-spherical systems. Application to LMXB

We study the appearance of the neutron star - accretion disk system as seen by a distant observer in the UV/X-ray domain. The observed intensity spectra are computed assuming non-spherical geometry of the whole system, in which outgoing spectrum is not represented by the flux spectrum, the latter being valid for spherically symmetric objects. Intensity spectra of our model display double bumps in UV/X-ray energy domains. Such structure is caused by the fact that the the source is not spherically symmetric, and the proper integration of intensity over emitted area is needed to reproduce observed spectral shape. Relative normalization of double bump is self consistently computed by our model. X-ray spectra of such a type were often observed in LMXB with accretion disk, ultra luminous X-ray sources, and accreting black hole systems with hot inner compact corona. Our model naturally explains high energy broadening of the disk spectrum observed in some binaries. We attempted to fit our model to X-ray data of XTE~J1709-267 from {\it XMM-Newton}. Unfortunately, the double intensity bump predicted by our model for LMXB is located in soft X-ray domain, uncovered by existing data for this source.Comment: 10 pages, 4 figures, submitted to Acta Astronomica, comments are wellcom

Two-component gap solitons with linear interconversion

We consider one-dimensional solitons in a binary Bose-Einstein condensate with linear coupling between the components, trapped in an optical-lattice potential. The inter-species and intra-species interactions may be both repulsive or attractive. Main effects considered here are spontaneous breaking of the symmetry between components in symmetric and antisymmetric solitons, and spatial splitting between the components. These effects are studied by means of a variational approximation and numerical simulations.Comment: 4 pages, 9 figure

ECONOMIC BURDEN OF SALMONELLA INFECTIONS IN THE UNITED STATES

The aim of this study is to evaluate medical expenditures and lost productivity associated with burden of Salmonella infections. We used laboratory confirmed number of Salmonella cases and corresponding multipliers to estimate the burden of illness using the method adopted by Foodborne Diseases Active Surveillance Network (FoodNet) at Centers for Disease Control and Prevention (CDC). The medical costs estimates are retrospective analysis of reimbursement records from MarketScan data. We identified patients with a diagnosis of salmonellosis using ICD-9 CM codes from the MarketScan 1993-2001 databases. Productivity loss from the nonfatal cases of Salmonella was calculated using the distributions of lost workdays and household services due to the illness. Statistical value of life approach was used to estimate the costs due to premature deaths. We also compared the costs for the gastrointestinal salmonellosis to the cost for the invasive salmonellosis. Confidence intervals around the cost estimates were calculated using a Monte Carlo simulation technique. Estimated average economic burden due to Salmonella was $210 per outpatient,$5,797 per inpatient with gastrointestinal infection, $16,441 per impatient with invasive infection and$4.63 million per premature death. Total economic buren due to Salmonella in the United States was estimated at $2.8 billion (95$1.6 to $5.3 billion) annually, which is approximately$2,472 per case of Salmonella infection. The cost estimate is largely driven by the number of premature deaths followed by average cost of hospitalization. Defining the risk factors for fatal outcomes may help target treatment and preventive strategies.Food Consumption/Nutrition/Food Safety,

Quantum Cloning, Bell's Inequality and Teleportation

We analyze a possibility of using the two qubit output state from Buzek-Hillery quantum copying machine (not necessarily universal quantum cloning machine) as a teleportation channel. We show that there is a range of values of the machine parameter $\xi$ for which the two qubit output state is entangled and violates Bell-CHSH inequality and for a different range it remains entangled but does not violate Bell-CHSH inequality. Further we observe that for certain values of the machine parameter the two-qubit mixed state can be used as a teleportation channel. The use of the output state from the Buzek-Hillery cloning machine as a teleportation channel provides an additional appeal to the cloning machine and motivation of our present work.Comment: 7 pages and no figures, Accepted in Journal of Physics