Long-Term Renal Function following Exposure to Petroleum Environmental Pollutants in the population of Ogoni Women,Niger Delta: A possible cellular mechanisms of Environmental Pollutants-induced Nephrotoxicity

Environmental toxic pollutants are of environmentalconcern because of its diversity of toxic effects in human body. In this study, randomly selected 184 female volunteers,94  from  Ogoni, Rivers State, Niger Delta and 90 from Ogoja Cross River State,consistently living in the petroleum exploration or gas and oil flaring region and non-petroleum production environments respectively, Nigeria, were used to estimate the contents of renal function indices  using standard procedures. Volunteers’ age ranged from 18 to 50 years. When compared to control, this study indicated significant high level of urea, creatinine, sodium and potassium with the ratio of urea to creatinine of 3:1 for the population of Ogoni women. Correlation coefficient analysis revealed significant positive relationship between heavy metals (lead, cadmium and vanadium) and renal function indices (urea and creatinine). An indication that environmental toxic pollutants cancause direct damage to the kidneysplausibly mediated by the combination of the high content of the exposed environmental pollutants and the induced high level of the renal toxins, specifically urea, which possibly fragmented blood cells without heat leading to nephrotoxicity.Additionally, the inference is that the population in the petroleum exploitation and exploration or oil and gas flaring environments are predisposed to renal dysfunction and are unaware

Cat States and Single Runs for the Damped Harmonic Oscillator

We discuss the fate of initial states of the cat type for the damped harmonic oscillator, mostly employing a linear version of the stochastic Schr\"odinger equation. We also comment on how such cat states might be prepared and on the relation of single realizations of the noise to single runs of experiments.Comment: 18, Revte

Retroactive quantum jumps in a strongly-coupled atom-field system

We investigate a novel type of conditional dynamic that occurs in the strongly-driven Jaynes-Cummings model with dissipation. Extending the work of Alsing and Carmichael [Quantum Opt. {\bf 3}, 13 (1991)], we present a combined numerical and analytic study of the Stochastic Master Equation that describes the system's conditional evolution when the cavity output is continuously observed via homodyne detection, but atomic spontaneous emission is not monitored at all. We find that quantum jumps of the atomic state are induced by its dynamical coupling to the optical field, in order retroactively to justify atypical fluctuations in ocurring in the homodyne photocurrent.Comment: 4 pages, uses RevTex, 5 EPS figure

Exact quantum jump approach to open systems in Bosonic and spin baths

A general method is developed which enables the exact treatment of the non-Markovian quantum dynamics of open systems through a Monte Carlo simulation technique. The method is based on a stochastic formulation of the von Neumann equation of the composite system and employs a pair of product states following a Markovian random jump process. The performance of the method is illustrated by means of stochastic simulations of the dynamics of open systems interacting with a Bosonic reservoir at zero temperature and with a spin bath in the strong coupling regime.Comment: 4 pages, 2 figure

Stochastic wave function method for non-Markovian quantum master equations

A generalization of the stochastic wave function method to quantum master equations which are not in Lindblad form is developed. The proposed stochastic unravelling is based on a description of the reduced system in a doubled Hilbert space and it is shown, that this method is capable of simulating quantum master equations with negative transition rates. Non-Markovian effects in the reduced systems dynamics can be treated within this approach by employing the time-convolutionless projection operator technique. This ansatz yields a systematic perturbative expansion of the reduced systems dynamics in the coupling strength. Several examples such as the damped Jaynes Cummings model and the spontaneous decay of a two-level system into a photonic band gap are discussed. The power as well as the limitations of the method are demonstrated.Comment: RevTex, 14 pages, 9 figures, uses multico

Many-body solitons in a one-dimensional condensate of hard core bosons

A mapping theorem leading to exact many-body dynamics of impenetrable bosons in one dimension reveals dark and gray soliton-like structures in a toroidal trap which is phase-imprinted. On long time scales revivals appear that are beyond the usual mean-field theory

Dark-Bright Solitons in Inhomogeneous Bose-Einstein Condensates

We investigate dark-bright vector solitary wave solutions to the coupled non-linear Schr\"odinger equations which describe an inhomogeneous two-species Bose-Einstein condensate. While these structures are well known in non-linear fiber optics, we show that spatial inhomogeneity strongly affects their motion, stability, and interaction, and that current technology suffices for their creation and control in ultracold trapped gases. The effects of controllably different interparticle scattering lengths, and stability against three-dimensional deformations, are also examined.Comment: 5 pages, 5 figure

Exact c-number Representation of Non-Markovian Quantum Dissipation

The reduced dynamics of a quantum system interacting with a linear heat bath finds an exact representation in terms of a stochastic Schr{\"o}dinger equation. All memory effects of the reservoir are transformed into noise correlations and mean-field friction. The classical limit of the resulting stochastic dynamics is shown to be a generalized Langevin equation, and conventional quantum state diffusion is recovered in the Born--Markov approximation. The non-Markovian exact dynamics, valid at arbitrary temperature and damping strength, is exemplified by an application to the dissipative two-state system.Comment: 4 pages, 2 figures. To be published in Phys. Rev. Let

Linear stochastic wave-equations for continuously measured quantum systems

While the linearity of the Schr\"odinger equation and the superposition principle are fundamental to quantum mechanics, so are the backaction of measurements and the resulting nonlinearity. It is remarkable, therefore, that the wave-equation of systems in continuous interaction with some reservoir, which may be a measuring device, can be cast into a linear form, even after the degrees of freedom of the reservoir have been eliminated. The superposition principle still holds for the stochastic wave-function of the observed system, and exact analytical solutions are possible in sufficiently simple cases. We discuss here the coupling to Markovian reservoirs appropriate for homodyne, heterodyne, and photon counting measurements. For these we present a derivation of the linear stochastic wave-equation from first principles and analyze its physical content.Comment: 34 pages, Revte

Interpretation of quantum jump and diffusion-processes illustrated on the Bloch sphere

It is shown that the evolution of an open quantum system whose density operator obeys a Markovian master equation can in some cases be meaningfully described in terms of stochastic Schrödinger equations (SSE’s) for its state vector. A necessary condition for this is that the information carried away from the system by the bath (source of the irreversibility) be recoverable. The primary field of application is quantum optics, where the bath consists of the continuum of electromagnetic modes. The information lost from the system can be recovered using a perfect photodetector. The state of the system conditioned on the photodetections undergoes stochastic quantum jumps. Alternative measurement schemes on the outgoing light (homodyne and heterodyne detection) are shown to give rise to SSE’s with diffusive terms. These three detection schemes are illustrated on a simple quantum system, the two-level atom, giving new perspectives on the interpretation of measurement results. The reality of these and other stochastic processes for state vectors is discussed