Non-Markovianity Measure Based on Brukner–Zeilinger Invariant Information for Unital Quantum Dynamical Maps

International Nuclear Information System (INIS)

He Zhi; Zhu Lie-Qiang; Li Li

2017-01-01

A non-Markovianity measure based on Brukner–Zeilinger invariant information to characterize non-Markovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner–Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner–Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information. (paper)

Non-Markovian features of deeply inelastic collisions

International Nuclear Information System (INIS)

Pal, D.; Chattopadhyay, S.; Kar, K.

1988-01-01

To study the effect of memory in the diffusion processes (of charge, mass etc) observed in deeply inelastic heavy-ion reactions, we derive non-Markovian transport equations for the exponential and Gaussian memory kernels. The centroid and the variance of the distribution are expressed in terms of the memory time, drift and diffusion coefficients. The predictions based on this theory show better agreement with the experimental data than the Markovian results. (author)

Bulk-mediated surface diffusion: non-Markovian desorption dynamics

International Nuclear Information System (INIS)

Revelli, Jorge A; Budde, Carlos E; Prato, Domingo; Wio, Horacio S

2005-01-01

Here we analyse the dynamics of adsorbed molecules within the bulk-mediated surface diffusion framework, when the particle's desorption mechanism is characterized by a non-Markovian process, while the particle's adsorption as well as its motion in the bulk is governed by Markovian dynamics. We study the diffusion of particles in both semi-infinite and finite cubic lattices, analysing the conditional probability to find the system on the reference absorptive plane as well as the surface dispersion as functions of time. The results are compared with known Markovian cases showing the differences that can be exploited to distinguish between Markovian and non-Markovian desorption mechanisms in experimental situations

Error Distributions on Large Entangled States with Non-Markovian Dynamics

DEFF Research Database (Denmark)

McCutcheon, Dara; Lindner, Netanel H.; Rudolph, Terry

2014-01-01

We investigate the distribution of errors on a computationally useful entangled state generated via the repeated emission from an emitter undergoing strongly non-Markovian evolution. For emitter-environment coupling of pure-dephasing form, we show that the probability that a particular patten...... of errors occurs has a bound of Markovian form, and thus, accuracy threshold theorems based on Markovian models should be just as effective. Beyond the pure-dephasing assumption, though complicated error structures can arise, they can still be qualitatively bounded by a Markovian error model....

Noise spectrum of quantum transport through double quantum dots: Renormalization and non-Markovian effects

Directory of Open Access Journals (Sweden)

Pengqin Shi

2016-09-01

Full Text Available Based on the time-nonlocal particle number-resolved master equation, we investigate the sequential electron transport through the interacting double quantum dots. Our calculations show that there exists the effect of energy renormalization in the dispersion of the bath interaction spectrum and it is sensitive to the the bandwidth of the bath. This effect would strongly affect the stationary current and its zero-frequency shot noise for weak inter-dot coherent coupling strength, but for strong inter-dot coupling regime, it is negligible due to the strong intrinsic Rabi coherent dynamics. Moreover, the possible observable effects of the energy renormalization in the noise spectrum are also investigated through the Rabi coherence signal. Finally, the non-Markovian effect is manifested in the finite-frequency noise spectrum with the appearance of quasisteps, and the magnitude of these quasisteps are modified by the dispersion function.

Non-Markovian effect on the geometric phase of a dissipative qubit

International Nuclear Information System (INIS)

Chen Juanjuan; Tong Qingjun; An Junhong; Luo Honggang; Oh, C. H.

2010-01-01

We studied the geometric phase of a two-level atom coupled to an environment with Lorentzian spectral density. The non-Markovian effect on the geometric phase is explored analytically and numerically. In the weak coupling limit, the lowest order correction to the geometric phase is derived analytically and the general case is calculated numerically. It was found that the correction to the geometric phase is significantly large if the spectral width is small, and in this case the non-Markovian dynamics has a significant impact on the geometric phase. When the spectral width increases, the correction to the geometric phase becomes negligible, which shows the robustness of the geometric phase to the environmental white noises. The result is significant to the quantum information processing based on the geometric phase.

Non-Markovian quantum Brownian motion in one dimension in electric fields

Science.gov (United States)

Shen, H. Z.; Su, S. L.; Zhou, Y. H.; Yi, X. X.

2018-04-01

Quantum Brownian motion is the random motion of quantum particles suspended in a field (or an effective field) resulting from their collision with fast-moving modes in the field. It provides us with a fundamental model to understand various physical features concerning open systems in chemistry, condensed-matter physics, biophysics, and optomechanics. In this paper, without either the Born-Markovian or rotating-wave approximation, we derive a master equation for a charged-Brownian particle in one dimension coupled with a thermal reservoir in electric fields. The effect of the reservoir and the electric fields is manifested as time-dependent coefficients and coherent terms, respectively, in the master equation. The two-photon correlation between the Brownian particle and the reservoir can induce nontrivial squeezing dynamics to the particle. We derive a current equation including the source from the driving fields, transient current from the system flowing into the environment, and the two-photon current caused by the non-rotating-wave term. The presented results then are compared with that given by the rotating-wave approximation in the weak-coupling limit, and these results are extended to a more general quantum network involving an arbitrary number of coupled-Brownian particles. The presented formalism might open a way to better understand exactly the non-Markovian quantum network.

Entanglement, non-Markovianity, and causal non-separability

Science.gov (United States)

Milz, Simon; Pollock, Felix A.; Le, Thao P.; Chiribella, Giulio; Modi, Kavan

2018-03-01

Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means of non-Markovian dynamics with a measurement on additional degrees of freedom. In detail, we provide an explicit construction to implement arbitrary a causal processes. Furthermore, we give necessary and sufficient conditions for open system dynamics with measurement to yield processes that respect causality locally, and find that tripartite entanglement and nonlocal unitary transformations are crucial requirements for the simulation of causally indefinite processes. These results show a direct connection between three counter-intuitive concepts: entanglement, non-Markovianity, and causal non-separability.

Mean first-passage times in confined media: from Markovian to non-Markovian processes

International Nuclear Information System (INIS)

Bénichou, O; Voituriez, R; Guérin, T

2015-01-01

We review recent theoretical works that enable the accurate evaluation of the mean first passage time (MFPT) of a random walker to a target in confinement for Markovian (memory-less) and non-Markovian walkers. For the Markovian problem, we present a general theory which allows one to accurately evaluate the MFPT and its extensions to related first-passage observables such as splitting probabilities and occupation times. We show that this analytical approach provides a universal scaling dependence of the MFPT on both the volume of the confining domain and the source–target distance in the case of general scale-invariant processes. This analysis is applicable to a broad range of stochastic processes characterized by length scale-invariant properties, and reveals the key role that can be played by the starting position of the random walker. We then present an extension to non-Markovian walks by taking the specific example of a tagged monomer of a polymer chain looking for a target in confinement. We show that the MFPT can be calculated accurately by computing the distribution of the positions of all the monomers in the chain at the instant of reaction. Such a theory can be used to derive asymptotic relations that generalize the scaling dependence with the volume and the initial distance to the target derived for Markovian walks. Finally, we present an application of this theory to the problem of the first contact time between the two ends of a polymer chain, and review the various theoretical approaches of this non- Markovian problem. (topical review)

Quantum measurements in spin-boson model under non-Markovian environment

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Berrada, K.; Aldaghri, O.

2017-07-01

We propose a control approach of the parameter estimation for a two-level quantum system interacting with a bosonic reservoir considering non-Markovian open, dissipative quantum system. We show that the precision of the estimation significantly affected and behaves differently within the framework of the markovian and non-Markovian regimes. The influence of memory effects for an Ohmic reservoir with Lorentz-Drude regularization on the estimation-parameter precision are numerically demonstrated under the following three conditions: ω0 ≪ωc , ω0 ≈ωc or ω0 ≫ωc , where ω0 is the characteristic frequency of the two-level system, and ωc is the cut-off frequency of Ohmic reservoir. We investigate the precision rate in high temperature, intermediate temperature, and low temperature reservoirs for various values of the ratio r =ωc /ω0 considering manifold external fields. We reveal that the enhancement and preservation of the measurement precision, highly depend on the combination of the external control field, reservoir parameters, and non-Markovian effects.

Exact non-Markovian master equations for multiple qubit systems: Quantum-trajectory approach

Science.gov (United States)

Chen, Yusui; You, J. Q.; Yu, Ting

2014-11-01

A wide class of exact master equations for a multiple qubit system can be explicitly constructed by using the corresponding exact non-Markovian quantum-state diffusion equations. These exact master equations arise naturally from the quantum decoherence dynamics of qubit system as a quantum memory coupled to a collective colored noisy source. The exact master equations are also important in optimal quantum control, quantum dissipation, and quantum thermodynamics. In this paper, we show that the exact non-Markovian master equation for a dissipative N -qubit system can be derived explicitly from the statistical average of the corresponding non-Markovian quantum trajectories. We illustrated our general formulation by an explicit construction of a three-qubit system coupled to a non-Markovian bosonic environment. This multiple qubit master equation offers an accurate time evolution of quantum systems in various domains, and paves the way to investigate the memory effect of an open system in a non-Markovian regime without any approximation.

Study on the security of discrete-variable quantum key distribution over non-Markovian channels

International Nuclear Information System (INIS)

Huang Peng; Zhu Jun; He Guangqiang; Zeng Guihua

2012-01-01

The dynamic of the secret key rate of the discrete-variable quantum key distribution (QKD) protocol over the non-Markovian quantum channel is investigated. In particular, we calculate the secret key rate for the six-state protocol over non-Markovian depolarizing channels with coloured noise and Markovian depolarizing channels with Gaussian white noise, respectively. We find that the secure secret key rate for the non-Markovian depolarizing channel will be larger than the Markovian one under the same conditions even when their upper bounds of tolerable quantum bit error rate are equal. This indicates that this coloured noise in the non-Markovian depolarizing channel can enhance the security of communication. Moreover, we show that the secret key rate fluctuates near the secure point when the coupling strength of the system with the environment is high. The results demonstrate that the non-Markovian effects of the transmission channel can have a positive impact on the security of discrete-variable QKD. (paper)

A classical appraisal of quantum definitions of non-Markovian dynamics

International Nuclear Information System (INIS)

Vacchini, Bassano

2012-01-01

We consider the issue of non-Markovianity of a quantum dynamics starting from a comparison with the classical definition of Markovian processes. We point to the fact that two sufficient but not necessary signatures of non-Markovianity of a classical process find their natural quantum counterpart in recently introduced measures of quantum non-Markovianity. This behaviour is analysed in detail for quantum dynamics which can be built taking as input a class of classical processes. (paper)

Controlling quantum memory-assisted entropic uncertainty in non-Markovian environments

Science.gov (United States)

Zhang, Yanliang; Fang, Maofa; Kang, Guodong; Zhou, Qingping

2018-03-01

Quantum memory-assisted entropic uncertainty relation (QMA EUR) addresses that the lower bound of Maassen and Uffink's entropic uncertainty relation (without quantum memory) can be broken. In this paper, we investigated the dynamical features of QMA EUR in the Markovian and non-Markovian dissipative environments. It is found that dynamical process of QMA EUR is oscillation in non-Markovian environment, and the strong interaction is favorable for suppressing the amount of entropic uncertainty. Furthermore, we presented two schemes by means of prior weak measurement and posterior weak measurement reversal to control the amount of entropic uncertainty of Pauli observables in dissipative environments. The numerical results show that the prior weak measurement can effectively reduce the wave peak values of the QMA-EUA dynamic process in non-Markovian environment for long periods of time, but it is ineffectual on the wave minima of dynamic process. However, the posterior weak measurement reversal has an opposite effects on the dynamic process. Moreover, the success probability entirely depends on the quantum measurement strength. We hope that our proposal could be verified experimentally and might possibly have future applications in quantum information processing.

Non-Markovianity Measure Based on Brukner-Zeilinger Invariant Information for Unital Quantum Dynamical Maps

Science.gov (United States)

He, Zhi; Zhu, Lie-Qiang; Li, Li

2017-03-01

A non-Markovianity measure based on Brukner-Zeilinger invariant information to characterize non-Markovian effect of open systems undergoing unital dynamical maps is proposed. The method takes advantage of non-increasing property of the Brukner-Zeilinger invariant information under completely positive and trace-preserving unital maps. The simplicity of computing the Brukner-Zeilinger invariant information is the advantage of the proposed measure because of mainly depending on the purity of quantum state. The measure effectively captures the characteristics of non-Markovianity of unital dynamical maps. As some concrete application, we consider two typical non-Markovian noise channels, i.e., the phase damping channel and the random unitary channel to show the sensitivity of the proposed measure. By investigation, we find that the conditions of detecting the non-Markovianity for the phase damping channel are consistent with the results of existing measures for non-Markovianity, i.e., information flow, divisibility and quantum mutual information. However, for the random unitary channel non-Markovian conditions are same to that of the information flow, but is different from that of the divisibility and quantum mutual information. Supported by the National Natural Science Foundation of China under Grant No. 61505053, the Natural Science Foundation of Hunan Province under Grant No. 2015JJ3092, the Research Foundation of Education Bureau of Hunan Province, China under Grant No. 16B177, the School Foundation from the Hunan University of Arts and Science under Grant No. 14ZD01

Pseudothermalization in driven-dissipative non-Markovian open quantum systems

Science.gov (United States)

Lebreuilly, José; Chiocchetta, Alessio; Carusotto, Iacopo

2018-03-01

We investigate a pseudothermalization effect, where an open quantum system coupled to a nonequilibrated environment consisting of several non-Markovian reservoirs presents an emergent thermal behavior. This thermal behavior is visible at both static and dynamical levels and the system satisfies the fluctuation-dissipation theorem. Our analysis is focused on the exactly solvable model of a weakly interacting driven-dissipative Bose gas in presence of frequency-dependent particle pumping and losses, and is based on a quantum Langevin theory, which we derive starting from a microscopical quantum optics model. For generic non-Markovian reservoirs, we demonstrate that the emergence of thermal properties occurs in the range of frequencies corresponding to low-energy excitations. For the specific case of non-Markovian baths verifying the Kennard-Stepanov relation, we show that pseudothermalization can instead occur at all energy scales. The possible implications regarding the interpretation of thermal laws in low-temperature exciton-polariton experiments are discussed. We finally show that the presence of either a saturable pumping or a dispersive environment leads to a breakdown of the pseudothermalization effect.

Non-Markovian entanglement dynamics of noisy continuous-variable quantum channels

International Nuclear Information System (INIS)

An, J.-H.; Zhang, W.-M.

2007-01-01

We investigate the entanglement dynamics of continuous-variable quantum channels in terms of an entangled squeezed state of two cavity fields in a general non-Markovian environment. Using the Feynman-Vernon influence functional theory in the coherent-state representation, we derive an exact master equation with time-dependent coefficients reflecting the non-Markovian influence of the environment. The influence of environments with different spectral densities, e.g., Ohmic, sub-Ohmic, and super-Ohmic, is numerically studied. The non-Markovian process shows its remarkable influence on the entanglement dynamics due to the sensitive time dependence of the dissipation and noise functions within the typical time scale of the environment. The Ohmic environment shows a weak dissipation-noise effect on the entanglement dynamics, while the sub-Ohmic and super-Ohmic environments induce much more severe noise. In particular, the memory of the system interacting with the environment contributes a strong decoherence effect to the entanglement dynamics in the super-Ohmic case

Colloquium: Non-Markovian dynamics in open quantum systems

Science.gov (United States)

Breuer, Heinz-Peter; Laine, Elsi-Mari; Piilo, Jyrki; Vacchini, Bassano

2016-04-01

The dynamical behavior of open quantum systems plays a key role in many applications of quantum mechanics, examples ranging from fundamental problems, such as the environment-induced decay of quantum coherence and relaxation in many-body systems, to applications in condensed matter theory, quantum transport, quantum chemistry, and quantum information. In close analogy to a classical Markovian stochastic process, the interaction of an open quantum system with a noisy environment is often modeled phenomenologically by means of a dynamical semigroup with a corresponding time-independent generator in Lindblad form, which describes a memoryless dynamics of the open system typically leading to an irreversible loss of characteristic quantum features. However, in many applications open systems exhibit pronounced memory effects and a revival of genuine quantum properties such as quantum coherence, correlations, and entanglement. Here recent theoretical results on the rich non-Markovian quantum dynamics of open systems are discussed, paying particular attention to the rigorous mathematical definition, to the physical interpretation and classification, as well as to the quantification of quantum memory effects. The general theory is illustrated by a series of physical examples. The analysis reveals that memory effects of the open system dynamics reflect characteristic features of the environment which opens a new perspective for applications, namely, to exploit a small open system as a quantum probe signifying nontrivial features of the environment it is interacting with. This Colloquium further explores the various physical sources of non-Markovian quantum dynamics, such as structured environmental spectral densities, nonlocal correlations between environmental degrees of freedom, and correlations in the initial system-environment state, in addition to developing schemes for their local detection. Recent experiments addressing the detection, quantification, and control of

Connecting two jumplike unravelings for non-Markovian open quantum systems

Energy Technology Data Exchange (ETDEWEB)

Luoma, Kimmo; Suominen, Kalle-Antti; Piilo, Jyrki [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turun Yliopisto (Finland)

2011-09-15

The development and use of Monte Carlo algorithms plays a visible role in the study of non-Markovian quantum dynamics due to the provided insight and powerful numerical methods for solving the system dynamics. In the Markovian case, the connections between the various types of methods are fairly well understood while, for the non-Markovian case, there has so far been only a few studies. We focus here on two jumplike unravelings of non-Markovian dynamics: the non-Markovian quantum jump (NMQJ) method and the property state method by Gambetta, Askerud, and Wiseman (GAW). The results for simple quantum optical systems illustrate the connections between the realizations of the two methods and also highlight how the probability currents between the system and environment, or between the property states of the total system, are associated with the decay rates of time-local master equations and, consequently, with the jump rates of the NMQJ method.

Connecting two jumplike unravelings for non-Markovian open quantum systems

International Nuclear Information System (INIS)

Luoma, Kimmo; Suominen, Kalle-Antti; Piilo, Jyrki

2011-01-01

The development and use of Monte Carlo algorithms plays a visible role in the study of non-Markovian quantum dynamics due to the provided insight and powerful numerical methods for solving the system dynamics. In the Markovian case, the connections between the various types of methods are fairly well understood while, for the non-Markovian case, there has so far been only a few studies. We focus here on two jumplike unravelings of non-Markovian dynamics: the non-Markovian quantum jump (NMQJ) method and the property state method by Gambetta, Askerud, and Wiseman (GAW). The results for simple quantum optical systems illustrate the connections between the realizations of the two methods and also highlight how the probability currents between the system and environment, or between the property states of the total system, are associated with the decay rates of time-local master equations and, consequently, with the jump rates of the NMQJ method.

Continuous quantum error correction for non-Markovian decoherence

International Nuclear Information System (INIS)

Oreshkov, Ognyan; Brun, Todd A.

2007-01-01

We study the effect of continuous quantum error correction in the case where each qubit in a codeword is subject to a general Hamiltonian interaction with an independent bath. We first consider the scheme in the case of a trivial single-qubit code, which provides useful insights into the workings of continuous error correction and the difference between Markovian and non-Markovian decoherence. We then study the model of a bit-flip code with each qubit coupled to an independent bath qubit and subject to continuous correction, and find its solution. We show that for sufficiently large error-correction rates, the encoded state approximately follows an evolution of the type of a single decohering qubit, but with an effectively decreased coupling constant. The factor by which the coupling constant is decreased scales quadratically with the error-correction rate. This is compared to the case of Markovian noise, where the decoherence rate is effectively decreased by a factor which scales only linearly with the rate of error correction. The quadratic enhancement depends on the existence of a Zeno regime in the Hamiltonian evolution which is absent in purely Markovian dynamics. We analyze the range of validity of this result and identify two relevant time scales. Finally, we extend the result to more general codes and argue that the performance of continuous error correction will exhibit the same qualitative characteristics

Selected Aspects of Markovian and Non-Markovian Quantum Master Equations

Science.gov (United States)

Lendi, K.

A few particular marked properties of quantum dynamical equations accounting for general relaxation and dissipation are selected and summarized in brief. Most results derive from the universal concept of complete positivity. The considerations mainly regard genuinely irreversible processes as characterized by a unique asymptotically stationary final state for arbitrary initial conditions. From ordinary Markovian master equations and associated quantum dynamical semigroup time-evolution, derivations of higher order Onsager coefficients and related entropy production are discussed. For general processes including non-faithful states a regularized version of quantum relative entropy is introduced. Further considerations extend to time-dependent infinitesimal generators of time-evolution and to a possible description of propagation of initial states entangled between open system and environment. In the coherence-vector representation of the full non-Markovian equations including entangled initial states, first results are outlined towards identifying mathematical properties of a restricted class of trial integral-kernel functions suited to phenomenological applications.

Thermodynamic description of non-Markovian information flux of nonequilibrium open quantum systems

Science.gov (United States)

Chen, Hong-Bin; Chen, Guang-Yin; Chen, Yueh-Nan

2017-12-01

One of the fundamental issues in the field of open quantum systems is the classification and quantification of non-Markovianity. In the contest of quantity-based measures of non-Markovianity, the intuition of non-Markovianity in terms of information backflow is widely discussed. However, it is not easy to characterize the information flux for a given system state and show its connection to non-Markovianity. Here, by using the concepts from thermodynamics and information theory, we discuss a potential definition of information flux of an open quantum system, valid for static environments. We present a simple protocol to show how a system attempts to share information with its environment and how it builds up system-environment correlations. We also show that the information returned from the correlations characterizes the non-Markovianity and a hierarchy of indivisibility of the system dynamics.

Shot-noise at a Fermi-edge singularity: Non-Markovian dynamics

Energy Technology Data Exchange (ETDEWEB)

Ubbelohde, N.; Maire, N.; Haug, R. J. [Institut für Festkörperphysik, Leibniz Universität Hannover, Appelstraße 2, D-30167 Hannover (Germany); Roszak, K. [Institute of Physics, Wrocław University of Technology, PL-50370 Wrocław (Poland); Hohls, F. [Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig (Germany); Novotný, T. [Department of Condensed Matter Physics, Faculty of Mathematics and Physics, Charles University, CZ-12116 Prague (Czech Republic)

2013-12-04

For an InAs quantum dot we study the current shot noise at a Fermi-edge singularity in low temperature cross-correlation measurements. In the regime of the interaction effect the strong suppression of noise observed at zero magnetic field and the sequence of enhancement and suppression in magnetic field go beyond a Markovian master equation model. Qualitative and quantitative agreement can however be achieved by a generalized master equation model taking non-Markovian dynamics into account.

Interpretation of non-Markovian stochastic Schroedinger equations as a hidden-variable theory

International Nuclear Information System (INIS)

Gambetta, Jay; Wiseman, H.M.

2003-01-01

Do diffusive non-Markovian stochastic Schroedinger equations (SSEs) for open quantum systems have a physical interpretation? In a recent paper [Phys. Rev. A 66, 012108 (2002)] we investigated this question using the orthodox interpretation of quantum mechanics. We found that the solution of a non-Markovian SSE represents the state the system would be in at that time if a measurement was performed on the environment at that time, and yielded a particular result. However, the linking of solutions at different times to make a trajectory is, we concluded, a fiction. In this paper we investigate this question using the modal (hidden variable) interpretation of quantum mechanics. We find that the noise function z(t) appearing in the non-Markovian SSE can be interpreted as a hidden variable for the environment. That is, some chosen property (beable) of the environment has a definite value z(t) even in the absence of measurement on the environment. The non-Markovian SSE gives the evolution of the state of the system 'conditioned' on this environment hidden variable. We present the theory for diffusive non-Markovian SSEs that have as their Markovian limit SSEs corresponding to homodyne and heterodyne detection, as well as one which has no Markovian limit

Non-Markovian quantum processes: Complete framework and efficient characterization

Science.gov (United States)

Pollock, Felix A.; Rodríguez-Rosario, César; Frauenheim, Thomas; Paternostro, Mauro; Modi, Kavan

2018-01-01

Currently, there is no systematic way to describe a quantum process with memory solely in terms of experimentally accessible quantities. However, recent technological advances mean we have control over systems at scales where memory effects are non-negligible. The lack of such an operational description has hindered advances in understanding physical, chemical, and biological processes, where often unjustified theoretical assumptions are made to render a dynamical description tractable. This has led to theories plagued with unphysical results and no consensus on what a quantum Markov (memoryless) process is. Here, we develop a universal framework to characterize arbitrary non-Markovian quantum processes. We show how a multitime non-Markovian process can be reconstructed experimentally, and that it has a natural representation as a many-body quantum state, where temporal correlations are mapped to spatial ones. Moreover, this state is expected to have an efficient matrix-product-operator form in many cases. Our framework constitutes a systematic tool for the effective description of memory-bearing open-system evolutions.

Non-Markovian linear response theory for quantum open systems and its applications.

Science.gov (United States)

Shen, H Z; Li, D X; Yi, X X

2017-01-01

The Kubo formula is an equation that expresses the linear response of an observable due to a time-dependent perturbation. It has been extended from closed systems to open systems in recent years under the Markovian approximation, but is barely explored for open systems in non-Markovian regimes. In this paper, we derive a formula for the linear response of an open system to a time-independent external field. This response formula is available for both Markovian and non-Markovian dynamics depending on parameters in the spectral density of the environment. As an illustration of the theory, the Hall conductance of a two-band system subjected to environments is derived and discussed. With the tight-binding model, we point out the Hall conductance changes from Markovian to non-Markovian dynamics by modulating the spectral density of the environment. Our results suggest a way to the controlling of the system response, which has potential applications for quantum statistical mechanics and condensed matter physics.

Non-Markovianity hinders Quantum Darwinism

Science.gov (United States)

Galve, Fernando; Zambrini, Roberta; Maniscalco, Sabrina

2016-01-01

We investigate Quantum Darwinism and the emergence of a classical world from the quantum one in connection with the spectral properties of the environment. We use a microscopic model of quantum environment in which, by changing a simple system parameter, we can modify the information back flow from environment into the system, and therefore its non-Markovian character. We show that the presence of memory effects hinders the emergence of classical objective reality, linking these two apparently unrelated concepts via a unique dynamical feature related to decoherence factors.

Non-Markovian spontaneous emission from a single quantum dot

DEFF Research Database (Denmark)

Madsen, Kristian Høeg; Ates, Serkan; Lund-Hansen, Toke

2011-01-01

We observe non-Markovian dynamics of a single quantum dot when tuned into resonance with a cavity mode. Excellent agreement between experiment and theory is observed providing the first quantitative description of such a system.......We observe non-Markovian dynamics of a single quantum dot when tuned into resonance with a cavity mode. Excellent agreement between experiment and theory is observed providing the first quantitative description of such a system....

Non-Markovian effects on quantum-communication protocols

International Nuclear Information System (INIS)

Yeo, Ye; Oh, C. H.; An, Jun-Hong

2010-01-01

We show how, under the influence of non-Markovian environments, two different maximally entangled Bell states give rise to states that have equal classical correlations and the same capacities to violate the Bell-Clauser-Horne-Shimony-Holt inequality, but intriguingly differing usefulness for teleportation and dense coding. We elucidate how different entanglement measures like negativity and concurrence, and two different measures of quantum discord, could account for these behaviors. In particular, we explicitly show how the Ollivier-Zurek measure of discord directly accounts for one state being a better resource for dense coding compared to another. Our study leads to several important issues about these measures of discord.

The quantum entropic uncertainty relation and entanglement witness in the two-atom system coupling with the non-Markovian environments

International Nuclear Information System (INIS)

Zou, Hong-Mei; Fang, Mao-Fa; Yang, Bai-Yuan; Guo, You-Neng; He, Wei; Zhang, Shi-Yang

2014-01-01

The quantum entropic uncertainty relation and entanglement witness in the two-atom system coupling with the non-Markovian environments are studied using the time-convolutionless master-equation approach. The influence of the non-Markovian effect and detuning on the lower bound of the quantum entropic uncertainty relation and entanglement witness is discussed in detail. The results show that, only if the two non-Markovian reservoirs are identical, increasing detuning and non-Markovian effect can reduce the lower bound of the entropic uncertainty relation, lengthen the time region during which the entanglement can be witnessed, and effectively protect the entanglement region witnessed by the lower bound of the entropic uncertainty relation. The results can be applied in quantum measurement, quantum cryptography tasks and quantum information processing. (paper)

Jump probabilities in the non-Markovian quantum jump method

International Nuclear Information System (INIS)

Haerkoenen, Kari

2010-01-01

The dynamics of a non-Markovian open quantum system described by a general time-local master equation is studied. The propagation of the density operator is constructed in terms of two processes: (i) deterministic evolution and (ii) evolution of a probability density functional in the projective Hilbert space. The analysis provides a derivation for the jump probabilities used in the recently developed non-Markovian quantum jump (NMQJ) method (Piilo et al 2008 Phys. Rev. Lett. 100 180402).

Non-Markovian reservoir-dependent squeezing

International Nuclear Information System (INIS)

Paavola, J

2010-01-01

The squeezing dynamics of a damped harmonic oscillator are studied for different types of environment without making the Markovian approximation. The squeezing dynamics of a coherent state depend on the reservoir spectrum in a unique way that can, in the weak coupling approximation, be analysed analytically. Comparison of squeezing dynamics for ohmic, sub-ohmic and super-ohmic environments is done, showing a clear connection between the squeezing-non-squeezing oscillations and reservoir structure. Understanding the effects occurring due to structured reservoirs is important both from a purely theoretical point of view and in connection with evolving experimental techniques and future quantum computing applications.

Non-Markovian dynamics in the theory of full counting statistics

DEFF Research Database (Denmark)

Flindt, Christian; Braggio, A.; Novotny, Tomas

2007-01-01

generating function corresponding to the resulting non-Markovian rate equation and find that the measured current cumulants behave significantly differently compared to those of a Markovian transport process. Our findings provide a novel interpretation of noise suppression found in a number of systems....

Enhancement of Quantum Correlations in Qubit-Qutrit Systems under the non-Markovian Environment

Institute of Scientific and Technical Information of China (English)

Abdul Basit; Hamad Ali; Fazal Badshah; Guo-Qin Ge

2017-01-01

We investigate the time evolution of quantum correlations of a hybrid qubit-qutrit system under the classical Ornstein-Uhlenbeck (OU) noise.Here we consider two different one-parameter families of qubit-qutrit states which independently interact with the non-Markovian reservoirs.A comparison with the Markovian dynamics reveals that for the same set of initial condition parameters,the non-Markovian behavior of the environment plays an important role in the enhancement of the survival time of quantum correlations.In addition,it is observed that the non-Markovian strength (γ/F) has a positive impact on the correlations time.For the initial separable states it is found that there is a finite time interval in which the geometric quantum discord is frozen despite the presence of a noisy environment and that interval can be further prolonged by using the non-Markovian property.Moreover,its decay can be significantly delayed.

Exact solution for a non-Markovian dissipative quantum dynamics.

Science.gov (United States)

Ferialdi, Luca; Bassi, Angelo

2012-04-27

We provide the exact analytic solution of the stochastic Schrödinger equation describing a harmonic oscillator interacting with a non-Markovian and dissipative environment. This result represents an arrival point in the study of non-Markovian dynamics via stochastic differential equations. It is also one of the few exactly solvable models for infinite-dimensional systems. We compute the Green's function; in the case of a free particle and with an exponentially correlated noise, we discuss the evolution of Gaussian wave functions.

Basic mechanisms in the laser control of non-Markovian dynamics

Science.gov (United States)

Puthumpally-Joseph, R.; Mangaud, E.; Chevet, V.; Desouter-Lecomte, M.; Sugny, D.; Atabek, O.

2018-03-01

Referring to a Fano-type model qualitative analogy we develop a comprehensive basic mechanism for the laser control of the non-Markovian bath response and fully implement it in a realistic control scheme, in strongly coupled open quantum systems. Converged hierarchical equations of motion are worked out to numerically solve the master equation of a spin-boson Hamiltonian to reach the reduced electronic density matrix of a heterojunction in the presence of strong terahertz laser pulses. Robust and efficient control is achieved increasing by a factor of 2 the non-Markovianity measured by the time evolution of the volume of accessible states. The consequences of such fields on the central system populations and coherence are examined, putting the emphasis on the relation between the increase of non-Markovianity and the slowing down of decoherence processes.

Evolution of entropy in different types of non-Markovian three-level ...

Indian Academy of Sciences (India)

ference between Markovian and non-Markovian systems lies in the memory ... In recent years, research on quantum entanglement has attracted a lot of attention, which .... Hamiltonians for three types of atoms in the interaction picture are.

Non-Markovianity and memory of the initial state

Science.gov (United States)

Hinarejos, Margarida; Bañuls, Mari-Carmen; Pérez, Armando; de Vega, Inés

2017-08-01

We explore in a rigorous manner the intuitive connection between the non-Markovianity of the evolution of an open quantum system and the performance of the system as a quantum memory. Using the paradigmatic case of a two-level open quantum system coupled to a bosonic bath, we compute the recovery fidelity, which measures the best possible performance of the system to store a qubit of information. We deduce that this quantity is connected, but not uniquely determined, by the non-Markovianity, for which we adopt the Breuer-Laine-Piilo measure proposed in Breuer et al (2009 Phys. Rev. Lett. 103 210401). We illustrate our findings with explicit calculations for the case of a structured environment.

Dynamics of density fluctuations in a non-Markovian Boltzmann- Langevin model

International Nuclear Information System (INIS)

Ayik, S.

1996-01-01

In the course of the past few years, the nuclear Boltzmann-Langevin (BL)model has emerged as a promising microscopic model for nuclear dynamics at intermediate energies. The BL model goes beyond the much employed Boltzmann-Uehling-Uhlenbeck (BUU) model, and hence it provides a basis for describing dynamics of density fluctuations and addressing processes exhibiting spontaneous symmetry breaking and catastrophic transformations in nuclear collisions, such as induced fission and multifragmentation. In these standard models, the collision term is treated in a Markovian approximation by assuming that two-body collisions are local in both space and time, in accordance with Boltzmann's original treatment. This simplification is usually justified by the fact that the duration of a two-body collision is short on the time scale characteristic of the macroscopic evolution of the system. As a result, transport properties of the collective motion has then a classical character. However, when the system possesses fast collective modes with characteristic energies that are not small in comparision with the temperature, then the quantum-statistical effects are important and the standard Markovian treatment is inadequate. In this case, it is necessary to improve the one-body transport model by including the memory effect due to the finite duration of two-body collisions. First we briefly describe the non-Markovian extension of the BL model by including the finite memory time associated with two-body collisions. Then, using this non-Markovian model in a linear response framework, we investigate the effect of the memory time on the agitation of unstable modes in nuclear matter in the spinodal zone, and calculate the collisional relaxation rates of nuclear collective vibrations

Non-Markovian dynamics, decoherence and entanglement in dissipative quantum systems with applications to quantum information theory of continuous variable systems

International Nuclear Information System (INIS)

Hoerhammer, C.

2007-01-01

In this thesis, non-Markovian dynamics, decoherence and entanglement in dissipative quantum systems are studied. In particular, applications to quantum information theory of continuous variable systems are considered. The non-Markovian dynamics are described by the Hu-Paz-Zhang master equation of quantum Brownian motion. In this context the focus is on non-Markovian effects on decoherence and separability time scales of various single- mode and two-mode continuous variable states. It is verified that moderate non-Markovian influences slow down the decay of interference fringes and quantum correlations, while strong non-Markovian effects resulting from an out-of-resonance bath can even accelerate the loss of coherence, compared to predictions of Markovian approximations. Qualitatively different scenarios including exponential, Gaussian or algebraic decay of the decoherence function are analyzed. It is shown that partial recurrence of coherence can occur in case of non-Lindblad-type dynamics. The time evolution of quantum correlations of entangled two-mode continuous variable states is examined in single-reservoir and two-reservoir models, representing noisy correlated or uncorrelated non-Markovian quantum channels. For this purpose the model of quantum Brownian motion is extended. Various separability criteria for Gaussian and non-Gaussian continuous variable systems are applied. In both types of reservoir models moderate non-Markovian effects prolong the separability time scales. However, in these models the properties of the stationary state may differ. In the two-reservoir model the initial entanglement is completely lost and both modes are finally uncorrelated. In a common reservoir both modes interact indirectly via the coupling to the same bath variables. Therefore, new quantum correlations may emerge between the two modes. Below a critical bath temperature entanglement is preserved even in the steady state. A separability criterion is derived, which depends

Quantum operation for a one-qubit system under a non-Markovian environment

International Nuclear Information System (INIS)

Xue Shibei; Zhang Jing; Wu Rebing; Li Chunwen; Tarn, Tzyh-Jong

2011-01-01

This paper introduces a simple alternating-current (AC) control strategy to perform quantum state manipulations under non-Markovian noise. A genetic algorithm is adopted to optimize the parameters of the AC control, which can be further used to fulfil one-qubit quantum operations at a given final time. Theoretical analysis and simulations show that our method works almost equally well for 1/f noise, ohmic, sub-ohmic and super-ohmic noise, which demonstrates the robustness of our strategy for noise with various spectra. In comparison with the Markovian cases, our method is more suitable to be used to suppress non-Markovian noise.

Non-Markovian Investigation of an Autonomous Quantum Heat Engine

Science.gov (United States)

Goyal, Ketan

A systematic study of a quantum heat engine is presented in this thesis. In particular, we study heat conduction through a two-two level composite system, which is then connected to a photon cavity to extract work, forming an autonomous quantum heat engine. The question as to what extent quantum effects such as quantum coherence and correlations impact thermodynamic properties of such a system is addressed. The investigated heat engine has been previously studied using the popular Born-Markovian quantum master equation under weak internal coupling approximation. However, we show that the used approach is quite limited in addressing such problems as it is incapable of correctly accounting for the quantum effects. By using a non-Markovian approach involving hierarchical equations of motion, we show that quantum coherence and correlations between system and environments play a significant role in energy transfer processes of heat conduction and work.

Femtosecond Non-Markovian Optical Dynamics in Solution

NARCIS (Netherlands)

Nibbering, Erik T.J.; Wiersma, Douwe A.; Duppen, Koos

1991-01-01

Femtosecond photon-echo experiments on sodium resorufin in dimethylsulfoxide at room temperature show that optical dephasing in solution is of non-Markovian character. A single Gauss-Markov stochastic modulation process is used to interpret both the femtosecond light-scattering results and the

Non-Markovianity of Gaussian Channels.

Science.gov (United States)

Torre, G; Roga, W; Illuminati, F

2015-08-14

We introduce a necessary and sufficient criterion for the non-Markovianity of Gaussian quantum dynamical maps based on the violation of divisibility. The criterion is derived by defining a general vectorial representation of the covariance matrix which is then exploited to determine the condition for the complete positivity of partial maps associated with arbitrary time intervals. Such construction does not rely on the Choi-Jamiolkowski representation and does not require optimization over states.

Uhrig dynamical control of a three-level system via non-Markovian quantum state diffusion

International Nuclear Information System (INIS)

Shu, Wenchong; Zhao, Xinyu; Jing, Jun; Yu, Ting; Wu, Lian-Ao

2013-01-01

In this paper, we use the quantum state diffusion (QSD) equation to implement the Uhrig dynamical decoupling to a three-level quantum system coupled to a non-Markovian reservoir comprising of infinite numbers of degrees of freedom. For this purpose, we first reformulate the non-Markovian QSD to incorporate the effect of the external control fields. With this stochastic QSD approach, we demonstrate that an unknown state of the three-level quantum system can be universally protected against both coloured phase and amplitude noises when the control-pulse sequences and control operators are properly designed. The advantage of using non-Markovian QSD equations is that the control dynamics of open quantum systems can be treated exactly without using Trotter product formula and be efficiently simulated even when the environment is comprised of infinite numbers of degrees of freedom. We also show how the control efficacy depends on the environment memory time and the designed time points of applied control pulses. (paper)

Computing the non-Markovian coarse-grained interactions derived from the Mori-Zwanzig formalism in molecular systems: Application to polymer melts

Science.gov (United States)

Li, Zhen; Lee, Hee Sun; Darve, Eric; Karniadakis, George Em

2017-01-01

Memory effects are often introduced during coarse-graining of a complex dynamical system. In particular, a generalized Langevin equation (GLE) for the coarse-grained (CG) system arises in the context of Mori-Zwanzig formalism. Upon a pairwise decomposition, GLE can be reformulated into its pairwise version, i.e., non-Markovian dissipative particle dynamics (DPD). GLE models the dynamics of a single coarse particle, while DPD considers the dynamics of many interacting CG particles, with both CG systems governed by non-Markovian interactions. We compare two different methods for the practical implementation of the non-Markovian interactions in GLE and DPD systems. More specifically, a direct evaluation of the non-Markovian (NM) terms is performed in LE-NM and DPD-NM models, which requires the storage of historical information that significantly increases computational complexity. Alternatively, we use a few auxiliary variables in LE-AUX and DPD-AUX models to replace the non-Markovian dynamics with a Markovian dynamics in a higher dimensional space, leading to a much reduced memory footprint and computational cost. In our numerical benchmarks, the GLE and non-Markovian DPD models are constructed from molecular dynamics (MD) simulations of star-polymer melts. Results show that a Markovian dynamics with auxiliary variables successfully generates equivalent non-Markovian dynamics consistent with the reference MD system, while maintaining a tractable computational cost. Also, transient subdiffusion of the star-polymers observed in the MD system can be reproduced by the coarse-grained models. The non-interacting particle models, LE-NM/AUX, are computationally much cheaper than the interacting particle models, DPD-NM/AUX. However, the pairwise models with momentum conservation are more appropriate for correctly reproducing the long-time hydrodynamics characterised by an algebraic decay in the velocity autocorrelation function.

Solutions for a non-Markovian diffusion equation

International Nuclear Information System (INIS)

Lenzi, E.K.; Evangelista, L.R.; Lenzi, M.K.; Ribeiro, H.V.; Oliveira, E.C. de

2010-01-01

Solutions for a non-Markovian diffusion equation are investigated. For this equation, we consider a spatial and time dependent diffusion coefficient and the presence of an absorbent term. The solutions exhibit an anomalous behavior which may be related to the solutions of fractional diffusion equations and anomalous diffusion.

Entanglement backflow under the composite effect of two non-Markovian reservoirs

International Nuclear Information System (INIS)

Li, Jun-Gang; Zou, Jian; Shao, Bin

2012-01-01

The entanglement backflow of two qubits coupled to two independent reservoirs is investigated. It is found that under the collective effects of the two independent reservoirs, the entanglement backflow of the qubits does not always increase with the increase of the non-Markovianity of one of the reservoirs but demonstrates an intricate behavior. Interestingly, the action of one reservoir can affect the other reservoir's contribution to the entanglement backflow even when the two reservoirs are independent. -- Highlights: ► We study entanglement backflow of two qubits coupled to two independent reservoirs. ► We find that the entanglement backflow demonstrates an intricate behavior. ► The action of one reservoir can affect the contribution of the other reservoir.

Sufficient conditions for positivity of non-Markovian master equations with Hermitian generators

International Nuclear Information System (INIS)

Wilkie, Joshua; Wong Yinmei

2009-01-01

We use basic physical motivations to develop sufficient conditions for positive semidefiniteness of the reduced density matrix for generalized non-Markovian integrodifferential Lindblad-Kossakowski master equations with Hermitian generators. We show that it is sufficient for the memory function to be the Fourier transform of a real positive symmetric frequency density function with certain properties. These requirements are physically motivated, and are more general and more easily checked than previously stated sufficient conditions. We also explore the decoherence dynamics numerically for some simple models using the Hadamard representation of the propagator. We show that the sufficient conditions are not necessary conditions. We also show that models exist in which the long time limit is in part determined by non-Markovian effects

Non-Markovian finite-temperature two-time correlation functions of system operators of a pure-dephasing model

International Nuclear Information System (INIS)

Goan, Hsi-Sheng; Jian, Chung-Chin; Chen, Po-Wen

2010-01-01

We evaluate the non-Markovian finite-temperature two-time correlation functions (CF's) of system operators of a pure-dephasing spin-boson model in two different ways, one by the direct exact operator technique and the other by the recently derived evolution equations, valid to second order in the system-environment interaction Hamiltonian. This pure-dephasing spin-boson model that is exactly solvable has been extensively studied as a simple decoherence model. However, its exact non-Markovian finite-temperature two-time system operator CF's, to our knowledge, have not been presented in the literature. This may be mainly due to the fact, illustrated in this article, that in contrast to the Markovian case, the time evolution of the reduced density matrix of the system (or the reduced quantum master equation) alone is not sufficient to calculate the two-time system operator CF's of non-Markovian open systems. The two-time CF's obtained using the recently derived evolution equations in the weak system-environment coupling case for this non-Markovian pure-dephasing model happen to be the same as those obtained from the exact evaluation. However, these results significantly differ from the non-Markovian two-time CF's obtained by wrongly directly applying the quantum regression theorem (QRT), a useful procedure to calculate the two-time CF's for weak-coupling Markovian open systems. This demonstrates clearly that the recently derived evolution equations generalize correctly the QRT to non-Markovian finite-temperature cases. It is believed that these evolution equations will have applications in many different branches of physics.

Bilayer graphene lattice-layer entanglement in the presence of non-Markovian phase noise

Science.gov (United States)

Bittencourt, Victor A. S. V.; Blasone, Massimo; Bernardini, Alex E.

2018-03-01

The evolution of single particle excitations of bilayer graphene under effects of non-Markovian noise is described with focus on the decoherence process of lattice-layer (LL) maximally entangled states. Once the noiseless dynamics of an arbitrary initial state is identified by the correspondence between the tight-binding Hamiltonian for the AB-stacked bilayer graphene and the Dirac equation—which includes pseudovectorlike and tensorlike field interactions—the noisy environment is described as random fluctuations on bias voltage and mass terms. The inclusion of noisy dynamics reproduces the Ornstein-Uhlenbeck processes: A non-Markovian noise model with a well-defined Markovian limit. Considering that an initial amount of entanglement shall be dissipated by the noise, two profiles of dissipation are identified. On one hand, for eigenstates of the noiseless Hamiltonian, deaths and revivals of entanglement are identified along the oscillation pattern for long interaction periods. On the other hand, for departing LL Werner and Cat states, the entanglement is suppressed although, for both cases, some identified memory effects compete with the pure noise-induced decoherence in order to preserve the the overall profile of a given initial state.

The simulation of the non-Markovian behaviour of a two-level system

Science.gov (United States)

Semina, I.; Petruccione, F.

2016-05-01

Non-Markovian relaxation dynamics of a two-level system is studied with the help of the non-linear stochastic Schrödinger equation with coloured Ornstein-Uhlenbeck noise. This stochastic Schrödinger equation is investigated numerically with an adapted Platen scheme. It is shown, that the memory effects have a significant impact to the dynamics of the system.

Counting statistics of non-markovian quantum stochastic processes

DEFF Research Database (Denmark)

Flindt, Christian; Novotny, T.; Braggio, A.

2008-01-01

We derive a general expression for the cumulant generating function (CGF) of non-Markovian quantum stochastic transport processes. The long-time limit of the CGF is determined by a single dominating pole of the resolvent of the memory kernel from which we extract the zero-frequency cumulants...

Simple non-Markovian microscopic models for the depolarizing channel of a single qubit

International Nuclear Information System (INIS)

Fonseca Romero, K M; Lo Franco, R

2012-01-01

The archetypal one-qubit noisy channels - depolarizing, phase-damping and amplitude-damping channels - describe both Markovian and non-Markovian evolution. Simple microscopic models for the depolarizing channel, both classical and quantum, are considered. Microscopic models that describe phase-damping and amplitude-damping channels are briefly reviewed.

Joint probability distributions for a class of non-Markovian processes.

Science.gov (United States)

Baule, A; Friedrich, R

2005-02-01

We consider joint probability distributions for the class of coupled Langevin equations introduced by Fogedby [H. C. Fogedby, Phys. Rev. E 50, 1657 (1994)]. We generalize well-known results for the single-time probability distributions to the case of N -time joint probability distributions. It is shown that these probability distribution functions can be obtained by an integral transform from distributions of a Markovian process. The integral kernel obeys a partial differential equation with fractional time derivatives reflecting the non-Markovian character of the process.

Dynamics of interacting qubits coupled to a common bath: Non-Markovian quantum-state-diffusion approach

International Nuclear Information System (INIS)

Zhao Xinyu; Jing Jun; Corn, Brittany; Yu Ting

2011-01-01

Non-Markovian dynamics is studied for two interacting qubits strongly coupled to a dissipative bosonic environment. We derive a non-Markovian quantum-state-diffusion (QSD) equation for the coupled two-qubit system without any approximations, and in particular, without the Markov approximation. As an application and illustration of our derived time-local QSD equation, we investigate the temporal behavior of quantum coherence dynamics. In particular, we find a strongly non-Markovian regime where entanglement generation is significantly modulated by the environmental memory. Additionally, we study residual entanglement in the steady state by analyzing the steady-state solution of the QSD equation. Finally, we discuss an approximate QSD equation.

A framework for the direct evaluation of large deviations in non-Markovian processes

International Nuclear Information System (INIS)

Cavallaro, Massimo; Harris, Rosemary J

2016-01-01

We propose a general framework to simulate stochastic trajectories with arbitrarily long memory dependence and efficiently evaluate large deviation functions associated to time-extensive observables. This extends the ‘cloning’ procedure of Giardiná et al (2006 Phys. Rev. Lett. 96 120603) to non-Markovian systems. We demonstrate the validity of this method by testing non-Markovian variants of an ion-channel model and the totally asymmetric exclusion process, recovering results obtainable by other means. (letter)

Population dynamics of excited atoms in non-Markovian environments at zero and finite temperature

International Nuclear Information System (INIS)

Zou Hong-Mei; Fang Mao-Fa

2015-01-01

The population dynamics of a two-atom system, which is in two independent Lorentzian reservoirs or in two independent Ohmic reservoirs respectively, where the reservoirs are at zero temperature or finite temperature, is studied by using the time-convolutionless master-equation method. The influences of the characteristics and temperature of a non-Markovian environment on the population of the excited atoms are analyzed. We find that the population trapping of the excited atoms is related to the characteristics and the temperature of the non-Markovian environment. The results show that, at zero temperature, the two atoms can be effectively trapped in the excited state both in the Lorentzian reservoirs and in the Ohmic reservoirs. At finite temperature, the population of the excited atoms will quickly decay to a nonzero value. (paper)

Bulk-mediated surface diffusion: non-Markovian desorption and biased behaviour in an infinite system

International Nuclear Information System (INIS)

Revelli, Jorge A; Budde, Carlos E; Wio, Horacio S

2005-01-01

We analyse the dynamics of adsorbed molecules within the bulk-mediated surface diffusion framework. We consider that the particle's desorption mechanism is characterized by a non-Markovian process, while the particle's adsorption and its motion in the bulk are governed by Markovian dynamics, and include the effect of an external field in the form of a bias in the normal motion to the surface. We study this system for the diffusion of particles in a semi-infinite lattice, analysing the conditional probability to find the system on the reference absorptive plane as well as the surface dispersion as functions of time. The agreement between numerical and analytical asymptotic results is discussed

Dynamics of non-Markovian exclusion processes

International Nuclear Information System (INIS)

Khoromskaia, Diana; Grosskinsky, Stefan; Harris, Rosemary J

2014-01-01

Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems. (paper)

Dynamics of non-Markovian exclusion processes

Science.gov (United States)

Khoromskaia, Diana; Harris, Rosemary J.; Grosskinsky, Stefan

2014-12-01

Driven diffusive systems are often used as simple discrete models of collective transport phenomena in physics, biology or social sciences. Restricting attention to one-dimensional geometries, the asymmetric simple exclusion process (ASEP) plays a paradigmatic role to describe noise-activated driven motion of entities subject to an excluded volume interaction and many variants have been studied in recent years. While in the standard ASEP the noise is Poissonian and the process is therefore Markovian, in many applications the statistics of the activating noise has a non-standard distribution with possible memory effects resulting from internal degrees of freedom or external sources. This leads to temporal correlations and can significantly affect the shape of the current-density relation as has been studied recently for a number of scenarios. In this paper we report a general framework to derive the fundamental diagram of ASEPs driven by non-Poissonian noise by using effectively only two simple quantities, viz., the mean residual lifetime of the jump distribution and a suitably defined temporal correlation length. We corroborate our results by detailed numerical studies for various noise statistics under periodic boundary conditions and discuss how our approach can be applied to more general driven diffusive systems.

Burst of virus infection and a possibly largest epidemic threshold of non-Markovian susceptible-infected-susceptible processes on networks

Science.gov (United States)

Liu, Qiang; Van Mieghem, Piet

2018-02-01

Since a real epidemic process is not necessarily Markovian, the epidemic threshold obtained under the Markovian assumption may be not realistic. To understand general non-Markovian epidemic processes on networks, we study the Weibullian susceptible-infected-susceptible (SIS) process in which the infection process is a renewal process with a Weibull time distribution. We find that, if the infection rate exceeds 1 /ln(λ1+1 ) , where λ1 is the largest eigenvalue of the network's adjacency matrix, then the infection will persist on the network under the mean-field approximation. Thus, 1 /ln(λ1+1 ) is possibly the largest epidemic threshold for a general non-Markovian SIS process with a Poisson curing process under the mean-field approximation. Furthermore, non-Markovian SIS processes may result in a multimodal prevalence. As a byproduct, we show that a limiting Weibullian SIS process has the potential to model bursts of a synchronized infection.

THE HALO MASS FUNCTION FROM EXCURSION SET THEORY. I. GAUSSIAN FLUCTUATIONS WITH NON-MARKOVIAN DEPENDENCE ON THE SMOOTHING SCALE

International Nuclear Information System (INIS)

Maggiore, Michele; Riotto, Antonio

2010-01-01

A classic method for computing the mass function of dark matter halos is provided by excursion set theory, where density perturbations evolve stochastically with the smoothing scale, and the problem of computing the probability of halo formation is mapped into the so-called first-passage time problem in the presence of a barrier. While the full dynamical complexity of halo formation can only be revealed through N-body simulations, excursion set theory provides a simple analytic framework for understanding various aspects of this complex process. In this series of papers we propose improvements of both technical and conceptual aspects of excursion set theory, and we explore up to which point the method can reproduce quantitatively the data from N-body simulations. In Paper I of the series, we show how to derive excursion set theory from a path integral formulation. This allows us both to derive rigorously the absorbing barrier boundary condition, that in the usual formulation is just postulated, and to deal analytically with the non-Markovian nature of the random walk. Such a non-Markovian dynamics inevitably enters when either the density is smoothed with filters such as the top-hat filter in coordinate space (which is the only filter associated with a well-defined halo mass) or when one considers non-Gaussian fluctuations. In these cases, beside 'Markovian' terms, we find 'memory' terms that reflect the non-Markovianity of the evolution with the smoothing scale. We develop a general formalism for evaluating perturbatively these non-Markovian corrections, and in this paper we perform explicitly the computation of the halo mass function for Gaussian fluctuations, to first order in the non-Markovian corrections due to the use of a top-hat filter in coordinate space. In Paper II of this series we propose to extend excursion set theory by treating the critical threshold for collapse as a stochastic variable, which better captures some of the dynamical complexity of the

Fault-tolerant quantum computation for local non-Markovian noise

International Nuclear Information System (INIS)

Terhal, Barbara M.; Burkard, Guido

2005-01-01

We derive a threshold result for fault-tolerant quantum computation for local non-Markovian noise models. The role of error amplitude in our analysis is played by the product of the elementary gate time t 0 and the spectral width of the interaction Hamiltonian between system and bath. We discuss extensions of our model and the applicability of our analysis

Optical signatures of non-Markovian behavior in open quantum systems

DEFF Research Database (Denmark)

McCutcheon, Dara

2016-01-01

for the correlation functions, making only a second-order expansion in the system-environment coupling strength and invoking the Born approximation at a fixed initial time. The results are used to investigate a driven semiconductor quantum dot coupled to an acoustic phonon bath, where we find the non-Markovian nature...

From BBGKY hierarchy to non-Markovian evolution equations

International Nuclear Information System (INIS)

Gerasimenko, V.I.; Shtyk, V.O.; Zagorodny, A.G.

2009-01-01

The problem of description of the evolution of the microscopic phase density and its generalizations is discussed. With this purpose, the sequence of marginal microscopic phase densities is introduced, and the appropriate BBGKY hierarchy for these microscopic distributions and their average values is formulated. The microscopic derivation of the generalized evolution equation for the average value of the microscopic phase density is given, and the non-Markovian generalization of the Fokker-Planck collision integral is proposed

An improved non-Markovian degradation model with long-term dependency and item-to-item uncertainty

Science.gov (United States)

Xi, Xiaopeng; Chen, Maoyin; Zhang, Hanwen; Zhou, Donghua

2018-05-01

It is widely noted in the literature that the degradation should be simplified into a memoryless Markovian process for the purpose of predicting the remaining useful life (RUL). However, there actually exists the long-term dependency in the degradation processes of some industrial systems, including electromechanical equipments, oil tankers, and large blast furnaces. This implies the new degradation state depends not only on the current state, but also on the historical states. Such dynamic systems cannot be accurately described by traditional Markovian models. Here we present an improved non-Markovian degradation model with both the long-term dependency and the item-to-item uncertainty. As a typical non-stationary process with dependent increments, fractional Brownian motion (FBM) is utilized to simulate the fractal diffusion of practical degradations. The uncertainty among multiple items can be represented by a random variable of the drift. Based on this model, the unknown parameters are estimated through the maximum likelihood (ML) algorithm, while a closed-form solution to the RUL distribution is further derived using a weak convergence theorem. The practicability of the proposed model is fully verified by two real-world examples. The results demonstrate that the proposed method can effectively reduce the prediction error.

Non-Markovian electron dynamics in nanostructures coupled to dissipative contacts

Science.gov (United States)

Novakovic, B.; Knezevic, I.

2013-02-01

In quasiballistic semiconductor nanostructures, carrier exchange between the active region and dissipative contacts is the mechanism that governs relaxation. In this paper, we present a theoretical treatment of transient quantum transport in quasiballistic semiconductor nanostructures, which is based on the open system theory and valid on timescales much longer than the characteristic relaxation time in the contacts. The approach relies on a model interaction between the current-limiting active region and the contacts, given in the scattering-state basis. We derive a non-Markovian master equation for the irreversible evolution of the active region's many-body statistical operator by coarse-graining the exact dynamical map over the contact relaxation time. In order to obtain the response quantities of a nanostructure under bias, such as the potential and the charge and current densities, the non-Markovian master equation must be solved numerically together with the Schr\\"{o}dinger, Poisson, and continuity equations. We discuss how to numerically solve this coupled system of equations and illustrate the approach on the example of a silicon nin diode.

System–environment correlations and non-Markovian dynamics

International Nuclear Information System (INIS)

Pernice, A; Helm, J; Strunz, W T

2012-01-01

We determine the total state dynamics of a dephasing open quantum system using the standard environment of harmonic oscillators. Of particular interest are random unitary approaches to the same reduced dynamics and system–environment correlations in the full model. Concentrating on a model with an at times negative dephasing rate, the issue of ‘non-Markovianity’ will also be addressed. Crucially, given the quantum environment, the appearance of non-Markovian dynamics turns out to be accompanied by a loss of system–environment correlations. Depending on the initial purity of the qubit state, these system–environment correlations may be purely classical over the whole relevant time scale, or there may be intervals of genuine system–environment entanglement. In the latter case, we see no obvious relation between the build-up or decay of these quantum correlations and ‘non-Markovianity’. (paper)

Large deviation estimates for a Non-Markovian Lévy generator of big order

International Nuclear Information System (INIS)

Léandre, Rémi

2015-01-01

We give large deviation estimates for a non-markovian convolution semi-group with a non-local generator of Lévy type of big order and with the standard normalisation of semi-classical analysis. No stochastic process is associated to this semi-group. (paper)

Evolution of entropy in different types of non-Markovian three-level ...

Indian Academy of Sciences (India)

Home; Journals; Pramana – Journal of Physics; Volume 86; Issue 5. Evolution of entropy in different types of non-Markovian three-level systems: Single reservoir vs. two independent reservoirs. JAGHOURI HAKIMEH SARBISHAEI MOHSEN JAVIDAN KUROSH. Regular Volume 86 Issue 5 May 2016 pp 997-1008 ...

Non-Markovian dynamics of a qubit due to single-photon scattering in a waveguide

Science.gov (United States)

Fang, Yao-Lung L.; Ciccarello, Francesco; Baranger, Harold U.

2018-04-01

We investigate the open dynamics of a qubit due to scattering of a single photon in an infinite or semi-infinite waveguide. Through an exact solution of the time-dependent multi-photon scattering problem, we find the qubit's dynamical map. Tools of open quantum systems theory allow us then to show the general features of this map, find the corresponding non-Linbladian master equation, and assess in a rigorous way its non-Markovian nature. The qubit dynamics has distinctive features that, in particular, do not occur in emission processes. Two fundamental sources of non-Markovianity are present: the finite width of the photon wavepacket and the time delay for propagation between the qubit and the end of the semi-infinite waveguide.

Evolution of entropy in different types of non-Markovian three-level ...

Indian Academy of Sciences (India)

We solve the Nakajima–Zwanzig (NZ) non-Markovian master equation to study the dynamics of different types of three-level atomic systems interacting with bosonic Lorentzian reservoirs at zero temperature. Von Neumann entropy (S) is used to show the evolution of the degree of entanglement of the subsystems.

Non-Markovian stochastic Schroedinger equations: Generalization to real-valued noise using quantum-measurement theory

International Nuclear Information System (INIS)

Gambetta, Jay; Wiseman, H.M.

2002-01-01

Do stochastic Schroedinger equations, also known as unravelings, have a physical interpretation? In the Markovian limit, where the system on average obeys a master equation, the answer is yes. Markovian stochastic Schroedinger equations generate quantum trajectories for the system state conditioned on continuously monitoring the bath. For a given master equation, there are many different unravelings, corresponding to different sorts of measurement on the bath. In this paper we address the non-Markovian case, and in particular the sort of stochastic Schroedinger equation introduced by Strunz, Diosi, and Gisin [Phys. Rev. Lett. 82, 1801 (1999)]. Using a quantum-measurement theory approach, we rederive their unraveling that involves complex-valued Gaussian noise. We also derive an unraveling involving real-valued Gaussian noise. We show that in the Markovian limit, these two unravelings correspond to heterodyne and homodyne detection, respectively. Although we use quantum-measurement theory to define these unravelings, we conclude that the stochastic evolution of the system state is not a true quantum trajectory, as the identity of the state through time is a fiction

Non-Markovian dynamics of quantum systems: formalism, transport coefficients

International Nuclear Information System (INIS)

Kanokov, Z.; Palchikov, Yu.V.; Antonenko, N.V.; Adamian, G.G.; Kanokov, Z.; Adamian, G.G.; Scheid, W.

2004-01-01

Full text: The generalized Linbland equations with non-stationary transport coefficients are derived from the Langevin equations for the case of nonlinear non-Markovian noise [1]. The equations of motion for the collective coordinates are consistent with the generalized quantum fluctuation dissipation relations. The microscopic justification of the Linbland axiomatic approach is performed. Explicit expressions for the time-dependent transport coefficients are presented for the case of FC- and RWA-oscillators and a general linear coupling in coordinate and in momentum between the collective subsystem and heat bath. The explicit equations for the correlation functions show that the Onsanger's regression hypothesis does not hold exactly for the non-Markovian equations of motion. However, under some conditions the regression of fluctuations goes to zero in the same manner as the average values. In the low and high temperature regimes we found that the dissipation leads to long-time tails in correlation functions in the RWA-oscillator. In the case of the FC-oscillator a non-exponential power-like decay of the correlation function in coordinate is only obtained only at the low temperature limit. The calculated results depend rather weakly on the memory time in many applications. The found transient times for diffusion coefficients D pp (t), D qp (t) and D qq (t) are quite short. The value of classical diffusion coefficients in momentum underestimates the asymptotic value of quantum one D pp (t), but the asymptotic values of classical σ qq c and quantum σ qq second moments are close due to the negativity of quantum mixed diffusion coefficient D qp (t)

Perturbative approach to non-Markovian stochastic Schroedinger equations

International Nuclear Information System (INIS)

Gambetta, Jay; Wiseman, H.M.

2002-01-01

In this paper we present a perturbative procedure that allows one to numerically solve diffusive non-Markovian stochastic Schroedinger equations, for a wide range of memory functions. To illustrate this procedure numerical results are presented for a classically driven two-level atom immersed in an environment with a simple memory function. It is observed that as the order of the perturbation is increased the numerical results for the ensemble average state ρ red (t) approach the exact reduced state found via Imamog-barlu ' s enlarged system method [Phys. Rev. A 50, 3650 (1994)

Quantum Non-Markovian Langevin Equations and Transport Coefficients

International Nuclear Information System (INIS)

Sargsyan, V.V.; Antonenko, N.V.; Kanokov, Z.; Adamian, G.G.

2005-01-01

Quantum diffusion equations featuring explicitly time-dependent transport coefficients are derived from generalized non-Markovian Langevin equations. Generalized fluctuation-dissipation relations and analytic expressions for calculating the friction and diffusion coefficients in nuclear processes are obtained. The asymptotic behavior of the transport coefficients and correlation functions for a damped harmonic oscillator that is linearly coupled in momentum to a heat bath is studied. The coupling to a heat bath in momentum is responsible for the appearance of the diffusion coefficient in coordinate. The problem of regression of correlations in quantum dissipative systems is analyzed

Quench of non-Markovian coherence in the deep sub-Ohmic spin–boson model: A unitary equilibration scheme

International Nuclear Information System (INIS)

Yao, Yao

2015-01-01

The deep sub-Ohmic spin–boson model shows a longstanding non-Markovian coherence at low temperature. Motivating to quench this robust coherence, the thermal effect is unitarily incorporated into the time evolution of the model, which is calculated by the adaptive time-dependent density matrix renormalization group algorithm combined with the orthogonal polynomials theory. Via introducing a unitary heating operator to the bosonic bath, the bath is heated up so that a majority portion of the bosonic excited states is occupied. It is found in this situation the coherence of the spin is quickly quenched even in the coherent regime, in which the non-Markovian feature dominates. With this finding we come up with a novel way to implement the unitary equilibration, the essential term of the eigenstate-thermalization hypothesis, through a short-time evolution of the model

Decoherence suppression of tripartite entanglement in non-Markovian environments by using weak measurements

Energy Technology Data Exchange (ETDEWEB)

Ding, Zhi-yong [School of Physics & Material Science, Anhui University, Hefei 230039 (China); School of Physics & Electronic Engineering, Fuyang Normal University, Fuyang 236037 (China); He, Juan, E-mail: juanhe78@163.com [School of Physics & Electronic Engineering, Fuyang Normal University, Fuyang 236037 (China); Ye, Liu, E-mail: yeliu@ahu.edu.cn [School of Physics & Material Science, Anhui University, Hefei 230039 (China)

2017-02-15

A feasible scheme for protecting the Greenberger–Horne–Zeilinger (GHZ) entanglement state in non-Markovian environments is proposed. It consists of prior weak measurement on each qubit before the interaction with decoherence environments followed by post quantum measurement reversals. It is shown that both the fidelity and concurrence of the GHZ state can be effectively improved. Meanwhile, we also verified that our scenario can enhance tripartite nonlocality remarkably. In addition, the result indicates that the larger the weak measurement strength, the better the effectiveness of the scheme with the lower success probability.

Counting statistics of transport through Coulomb blockade nanostructures: High-order cumulants and non-Markovian effects

DEFF Research Database (Denmark)

Flindt, Christian; Novotny, Tomás; Braggio, Alessandro

2010-01-01

Recent experimental progress has made it possible to detect in real-time single electrons tunneling through Coulomb blockade nanostructures, thereby allowing for precise measurements of the statistical distribution of the number of transferred charges, the so-called full counting statistics...... interactions. Our recursive method can treat systems with many states as well as non-Markovian dynamics. We illustrate our approach with three examples of current experimental relevance: bunching transport through a two-level quantum dot, transport through a nanoelectromechanical system with dynamical Franck...

Landau-Zener evolution under weak measurement: manifestation of the Zeno effect under diabatic and adiabatic measurement protocols

Science.gov (United States)

Novelli, Anna; Belzig, Wolfgang; Nitzan, Abraham

2015-01-01

The time evolution and the asymptotic outcome of a Landau-Zener-Stueckelberg-Majorana (LZ) process under continuous weak non-selective measurement is analyzed. We compare two measurement protocols in which the populations of either the adiabatic or the non-adiabatic levels are (continuously and weakly) monitored. The weak measurement formalism, described using a Gaussian Kraus operator, leads to a time evolution characterized by a Markovian dephasing process, which, in the non-adiabatic measurement protocol is similar to earlier studies of LZ dynamics in a dephasing environment. Casting the problem in the language of measurement theory makes it possible for us to compare diabatic and adiabatic measurement scenarios, to consider engineered dephasing as a control device and to examine the manifestation of the Zeno effect under the different measurement protocols. In particular, under measurement of the non-adiabatic populations, the Zeno effect is manifested not as a freezing of the measured system in its initial state, but rather as an approach to equal asymptotic populations of the two diabatic states. This behavior can be traced to the way by which the weak measurement formalism behaves in the strong measurement limit, with a built-in relationship between measurement time and strength.

Non-Markovian near-infrared Q branch of HCl diluted in liquid Ar.

Science.gov (United States)

Padilla, Antonio; Pérez, Justo

2013-08-28

By using a non-Markovian spectral theory based in the Kubo cumulant expansion technique, we have qualitatively studied the infrared Q branch observed in the fundamental absorption band of HCl diluted in liquid Ar. The statistical parameters of the anisotropic interaction present in this spectral theory were calculated by means of molecular dynamics techniques, and found that the values of the anisotropic correlation times are significantly greater (by a factor of two) than those previously obtained by fitting procedures or microscopic cell models. This fact is decisive for the observation in the theoretical spectral band of a central Q resonance which is absent in the abundant previous researches carried out with the usual theories based in Kubo cumulant expansion techniques. Although the theory used in this work only allows a qualitative study of the Q branch, we can employ it to study the unknown characteristics of the Q resonance which are difficult to obtain with the quantum simulation techniques recently developed. For example, in this study we have found that the Q branch is basically a non-Markovian (or memory) effect produced by the spectral line interferences, where the PR interferential profile basically determines the Q branch spectral shape. Furthermore, we have found that the Q resonance is principally generated by the first rotational states of the first two vibrational levels, those more affected by the action of the dissolvent.

Non-Markovianity in the optimal control of an open quantum system described by hierarchical equations of motion

Science.gov (United States)

Mangaud, E.; Puthumpally-Joseph, R.; Sugny, D.; Meier, C.; Atabek, O.; Desouter-Lecomte, M.

2018-04-01

Optimal control theory is implemented with fully converged hierarchical equations of motion (HEOM) describing the time evolution of an open system density matrix strongly coupled to the bath in a spin-boson model. The populations of the two-level sub-system are taken as control objectives; namely, their revivals or exchange when switching off the field. We, in parallel, analyze how the optimal electric field consequently modifies the information back flow from the environment through different non-Markovian witnesses. Although the control field has a dipole interaction with the central sub-system only, its indirect influence on the bath collective mode dynamics is probed through HEOM auxiliary matrices, revealing a strong correlation between control and dissipation during a non-Markovian process. A heterojunction is taken as an illustrative example for modeling in a realistic way the two-level sub-system parameters and its spectral density function leading to a non-perturbative strong coupling regime with the bath. Although, due to strong system-bath couplings, control performances remain rather modest, the most important result is a noticeable increase of the non-Markovian bath response induced by the optimally driven processes.

Non-Markovian dynamics of dust charge fluctuations in dusty plasmas

Science.gov (United States)

Asgari, H.; Muniandy, S. V.; Ghalee, Amir; Ghalee

2014-06-01

Dust charge fluctuates even in steady-state uniform plasma due to the discrete nature of the charge carriers and can be described using standard Langevin equation. In this work, two possible approaches in order to introduce the memory effect in dust charging dynamics are proposed. The first part of the paper provides the generalization form of the fluctuation-dissipation relation for non-Markovian systems based on generalized Langevin equations to determine the amplitudes of the dust charge fluctuations for two different kinds of colored noises under the assumption that the fluctuation-dissipation relation is valid. In the second part of the paper, aiming for dusty plasma system out of equilibrium, the fractionalized Langevin equation is used to derive the temporal two-point correlation function of grain charge fluctuations which is shown to be non-stationary due to the dependence on both times and not the time difference. The correlation function is used to derive the amplitude of fluctuations for early transient time.

Exploiting Non-Markovianity for Quantum Control.

Science.gov (United States)

Reich, Daniel M; Katz, Nadav; Koch, Christiane P

2015-07-22

Quantum technology, exploiting entanglement and the wave nature of matter, relies on the ability to accurately control quantum systems. Quantum control is often compromised by the interaction of the system with its environment since this causes loss of amplitude and phase. However, when the dynamics of the open quantum system is non-Markovian, amplitude and phase flow not only from the system into the environment but also back. Interaction with the environment is then not necessarily detrimental. We show that the back-flow of amplitude and phase can be exploited to carry out quantum control tasks that could not be realized if the system was isolated. The control is facilitated by a few strongly coupled, sufficiently isolated environmental modes. Our paradigmatic example considers a weakly anharmonic ladder with resonant amplitude control only, restricting realizable operations to SO(N). The coupling to the environment, when harnessed with optimization techniques, allows for full SU(N) controllability.

Landau–Zener evolution under weak measurement: manifestation of the Zeno effect under diabatic and adiabatic measurement protocols

International Nuclear Information System (INIS)

Novelli, Anna; Belzig, Wolfgang; Nitzan, Abraham

2015-01-01

The time evolution and the asymptotic outcome of a Landau–Zener–Stueckelberg–Majorana (LZ) process under continuous weak non-selective measurement is analyzed. We compare two measurement protocols in which the populations of either the adiabatic or the non-adiabatic levels are (continuously and weakly) monitored. The weak measurement formalism, described using a Gaussian Kraus operator, leads to a time evolution characterized by a Markovian dephasing process, which, in the non-adiabatic measurement protocol is similar to earlier studies of LZ dynamics in a dephasing environment. Casting the problem in the language of measurement theory makes it possible for us to compare diabatic and adiabatic measurement scenarios, to consider engineered dephasing as a control device and to examine the manifestation of the Zeno effect under the different measurement protocols. In particular, under measurement of the non-adiabatic populations, the Zeno effect is manifested not as a freezing of the measured system in its initial state, but rather as an approach to equal asymptotic populations of the two diabatic states. This behavior can be traced to the way by which the weak measurement formalism behaves in the strong measurement limit, with a built-in relationship between measurement time and strength. (paper)

Non-Markovian dynamics, decoherence and entanglement in dissipative quantum systems with applications to quantum information theory of continuous variable systems; Nicht-Markovsche Dynamik, Dekohaerenz und Verschraenkung in dissipativen Quantensystemen mit Anwendung in der Quanteninformationstheorie von Systemen kontinuierlicher Variablen

Energy Technology Data Exchange (ETDEWEB)

Hoerhammer, C.

2007-11-26

In this thesis, non-Markovian dynamics, decoherence and entanglement in dissipative quantum systems are studied. In particular, applications to quantum information theory of continuous variable systems are considered. The non-Markovian dynamics are described by the Hu-Paz-Zhang master equation of quantum Brownian motion. In this context the focus is on non-Markovian effects on decoherence and separability time scales of various single- mode and two-mode continuous variable states. It is verified that moderate non-Markovian influences slow down the decay of interference fringes and quantum correlations, while strong non-Markovian effects resulting from an out-of-resonance bath can even accelerate the loss of coherence, compared to predictions of Markovian approximations. Qualitatively different scenarios including exponential, Gaussian or algebraic decay of the decoherence function are analyzed. It is shown that partial recurrence of coherence can occur in case of non-Lindblad-type dynamics. The time evolution of quantum correlations of entangled two-mode continuous variable states is examined in single-reservoir and two-reservoir models, representing noisy correlated or uncorrelated non-Markovian quantum channels. For this purpose the model of quantum Brownian motion is extended. Various separability criteria for Gaussian and non-Gaussian continuous variable systems are applied. In both types of reservoir models moderate non-Markovian effects prolong the separability time scales. However, in these models the properties of the stationary state may differ. In the two-reservoir model the initial entanglement is completely lost and both modes are finally uncorrelated. In a common reservoir both modes interact indirectly via the coupling to the same bath variables. Therefore, new quantum correlations may emerge between the two modes. Below a critical bath temperature entanglement is preserved even in the steady state. A separability criterion is derived, which depends

Noninvasive Quantum Measurement of Arbitrary Operator Order by Engineered Non-Markovian Detectors

Science.gov (United States)

Bülte, Johannes; Bednorz, Adam; Bruder, Christoph; Belzig, Wolfgang

2018-04-01

The development of solid-state quantum technologies requires the understanding of quantum measurements in interacting, nonisolated quantum systems. In general, a permanent coupling of detectors to a quantum system leads to memory effects that have to be taken into account in interpreting the measurement results. We analyze a generic setup of two detectors coupled to a quantum system and derive a compact formula in the weak-measurement limit that interpolates between an instantaneous (text-book type) and almost continuous—detector dynamics-dependent—measurement. A quantum memory effect that we term "system-mediated detector-detector interaction" is crucial to observe noncommuting observables simultaneously. Finally, we propose a mesoscopic double-dot detector setup in which the memory effect is tunable and that can be used to explore the transition to non-Markovian quantum measurements experimentally.

Non-Markovian reduced dynamics of ultrafast charge transfer at an oligothiophene–fullerene heterojunction

Energy Technology Data Exchange (ETDEWEB)

Hughes, Keith H., E-mail: keith.hughes@bangor.ac.uk [School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom); Cahier, Benjamin [School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom); Martinazzo, Rocco [Dipartimento di Chimica Università degli Studi di Milano, v. Golgi 19, 20133 Milano (Italy); Tamura, Hiroyuki [WPI-Advanced Institute for Material Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Burghardt, Irene [Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt/Main (Germany)

2014-10-17

Highlights: • Quantum dynamical study of exciton dissociation at a heterojunction interface. • The non-Markovian quantum dynamics involves a highly structured spectral density. • Spectral density is reconstructed from an effective mode transformation of the Hamiltonian. • The dynamics is studied using the hierarchical equations of motion approach. • It was found that the temperature has little effect on the charge transfer. - Abstract: We extend our recent quantum dynamical study of the exciton dissociation and charge transfer at an oligothiophene–fullerene heterojunction interface (Tamura et al., 2012) [6] by investigating the process using the non-perturbative hierarchical equations of motion (HEOM) approach. Based upon an effective mode reconstruction of the spectral density the effect of temperature on the charge transfer is studied using reduced density matrices. It was found that the temperature had little effect on the charge transfer and a coherent dynamics persists over the first few tens of femtoseconds, indicating that the primary charge transfer step proceeds by an activationless pathway.

Stochastic wave-function simulation of irreversible emission processes for open quantum systems in a non-Markovian environment

Science.gov (United States)

Polyakov, Evgeny A.; Rubtsov, Alexey N.

2018-02-01

When conducting the numerical simulation of quantum transport, the main obstacle is a rapid growth of the dimension of entangled Hilbert subspace. The Quantum Monte Carlo simulation techniques, while being capable of treating the problems of high dimension, are hindered by the so-called "sign problem". In the quantum transport, we have fundamental asymmetry between the processes of emission and absorption of environment excitations: the emitted excitations are rapidly and irreversibly scattered away. Whereas only a small part of these excitations is absorbed back by the open subsystem, thus exercising the non-Markovian self-action of the subsystem onto itself. We were able to devise a method for the exact simulation of the dominant quantum emission processes, while taking into account the small backaction effects in an approximate self-consistent way. Such an approach allows us to efficiently conduct simulations of real-time dynamics of small quantum subsystems immersed in non-Markovian bath for large times, reaching the quasistationary regime. As an example we calculate the spatial quench dynamics of Kondo cloud for a bozonized Kodno impurity model.

Non-Markovian dynamics of charge carriers in quantum dots

International Nuclear Information System (INIS)

Vaz, E; Kyriakidis, J

2008-01-01

We have investigated the dynamics of bound particles in multilevel current-carrying quantum dots. We look specifically in the regime of resonant tunnelling transport, where several channels are available for transport. Through a non-Markovian formalism under the Born approximation, we investigate the real-time evolution of the confined particles including transport-induced decoherence and relaxation. In the case of a coherent superposition between states with different particle number, we find that a Fock-space coherence may be preserved even in the presence of tunneling into and out of the dot. Real-time results are presented for various asymmetries of tunneling rates into different orbitals

Non-Markovian dissipative quantum mechanics with stochastic trajectories

International Nuclear Information System (INIS)

Koch, Werner

2010-01-01

All fields of physics - be it nuclear, atomic and molecular, solid state, or optical - offer examples of systems which are strongly influenced by the environment of the actual system under investigation. The scope of what is called ''the environment'' may vary, i.e., how far from the system of interest an interaction between the two does persist. Typically, however, it is much larger than the open system itself. Hence, a fully quantum mechanical treatment of the combined system without approximations and without limitations of the type of system is currently out of reach. With the single assumption of the environment to consist of an internally thermalized set of infinitely many harmonic oscillators, the seminal work of Stockburger and Grabert [Chem. Phys., 268:249-256, 2001] introduced an open system description that captures the environmental influence by means of a stochastic driving of the reduced system. The resulting stochastic Liouville-von Neumann equation describes the full non-Markovian dynamics without explicit memory but instead accounts for it implicitly through the correlations of the complex-valued noise forces. The present thesis provides a first application of the Stockburger-Grabert stochastic Liouville-von Neumann equation to the computation of the dynamics of anharmonic, continuous open systems. In particular, it is demonstrated that trajectory based propagators allow for the construction of a numerically stable propagation scheme. With this approach it becomes possible to achieve the tremendous increase of the noise sample count necessary to stochastically converge the results when investigating such systems with continuous variables. After a test against available analytic results for the dissipative harmonic oscillator, the approach is subsequently applied to the analysis of two different realistic, physical systems. As a first example, the dynamics of a dissipative molecular oscillator is investigated. Long time propagation - until

Stochastic representation of a class of non-Markovian completely positive evolutions

International Nuclear Information System (INIS)

Budini, Adrian A.

2004-01-01

By modeling the interaction of an open quantum system with its environment through a natural generalization of the classical concept of continuous time random walk, we derive and characterize a class of non-Markovian master equations whose solution is a completely positive map. The structure of these master equations is associated with a random renewal process where each event consist in the application of a superoperator over a density matrix. Strong nonexponential decay arise by choosing different statistics of the renewal process. As examples we analyze the stochastic and averaged dynamics of simple systems that admit an analytical solution. The problem of positivity in quantum master equations induced by memory effects [S. M. Barnett and S. Stenholm, Phys. Rev. A 64, 033808 (2001)] is clarified in this context

Zero-crossing statistics for non-Markovian time series.

Science.gov (United States)

Nyberg, Markus; Lizana, Ludvig; Ambjörnsson, Tobias

2018-03-01

In applications spanning from image analysis and speech recognition to energy dissipation in turbulence and time-to failure of fatigued materials, researchers and engineers want to calculate how often a stochastic observable crosses a specific level, such as zero. At first glance this problem looks simple, but it is in fact theoretically very challenging, and therefore few exact results exist. One exception is the celebrated Rice formula that gives the mean number of zero crossings in a fixed time interval of a zero-mean Gaussian stationary process. In this study we use the so-called independent interval approximation to go beyond Rice's result and derive analytic expressions for all higher-order zero-crossing cumulants and moments. Our results agree well with simulations for the non-Markovian autoregressive model.

Zero-crossing statistics for non-Markovian time series

Science.gov (United States)

Nyberg, Markus; Lizana, Ludvig; Ambjörnsson, Tobias

2018-03-01

In applications spanning from image analysis and speech recognition to energy dissipation in turbulence and time-to failure of fatigued materials, researchers and engineers want to calculate how often a stochastic observable crosses a specific level, such as zero. At first glance this problem looks simple, but it is in fact theoretically very challenging, and therefore few exact results exist. One exception is the celebrated Rice formula that gives the mean number of zero crossings in a fixed time interval of a zero-mean Gaussian stationary process. In this study we use the so-called independent interval approximation to go beyond Rice's result and derive analytic expressions for all higher-order zero-crossing cumulants and moments. Our results agree well with simulations for the non-Markovian autoregressive model.

Generalized formalism for information backflow in assessing Markovianity and its equivalence to divisibility

Science.gov (United States)

Chakraborty, Sagnik

2018-03-01

We present a general framework for the information backflow (IB) approach of Markovianity that not only includes a large number, if not all, of IB prescriptions proposed so far but also is equivalent to completely positive divisibility for invertible evolutions. Following the common approach of IB, where monotonic decay of some physical property or some information quantifier is seen as the definition of Markovianity, we propose in our framework a general description of what should be called a proper "physicality quantifier" to define Markovianity. We elucidate different properties of our framework and use them to argue that an infinite family of non-Markovianity measures can be constructed, which would capture varied strengths of non-Markovianity in the dynamics. Moreover, we show that generalized trace-distance measure in two dimensions serve as a sufficient criteria for IB Markovianity for a number of prescriptions suggested earlier in the literature.

Non-Markovian dissipative quantum mechanics with stochastic trajectories

Energy Technology Data Exchange (ETDEWEB)

Koch, Werner

2010-09-09

All fields of physics - be it nuclear, atomic and molecular, solid state, or optical - offer examples of systems which are strongly influenced by the environment of the actual system under investigation. The scope of what is called ''the environment'' may vary, i.e., how far from the system of interest an interaction between the two does persist. Typically, however, it is much larger than the open system itself. Hence, a fully quantum mechanical treatment of the combined system without approximations and without limitations of the type of system is currently out of reach. With the single assumption of the environment to consist of an internally thermalized set of infinitely many harmonic oscillators, the seminal work of Stockburger and Grabert [Chem. Phys., 268:249-256, 2001] introduced an open system description that captures the environmental influence by means of a stochastic driving of the reduced system. The resulting stochastic Liouville-von Neumann equation describes the full non-Markovian dynamics without explicit memory but instead accounts for it implicitly through the correlations of the complex-valued noise forces. The present thesis provides a first application of the Stockburger-Grabert stochastic Liouville-von Neumann equation to the computation of the dynamics of anharmonic, continuous open systems. In particular, it is demonstrated that trajectory based propagators allow for the construction of a numerically stable propagation scheme. With this approach it becomes possible to achieve the tremendous increase of the noise sample count necessary to stochastically converge the results when investigating such systems with continuous variables. After a test against available analytic results for the dissipative harmonic oscillator, the approach is subsequently applied to the analysis of two different realistic, physical systems. As a first example, the dynamics of a dissipative molecular oscillator is investigated. Long time

Noise suppression via generalized-Markovian processes

Science.gov (United States)

Marshall, Jeffrey; Campos Venuti, Lorenzo; Zanardi, Paolo

2017-11-01

It is by now well established that noise itself can be useful for performing quantum information processing tasks. We present results which show how one can effectively reduce the error rate associated with a noisy quantum channel by counteracting its detrimental effects with another form of noise. In particular, we consider the effect of adding on top of a purely Markovian (Lindblad) dynamics, a more general form of dissipation, which we refer to as generalized-Markovian noise. This noise has an associated memory kernel and the resulting dynamics are described by an integrodifferential equation. The overall dynamics are characterized by decay rates which depend not only on the original dissipative time scales but also on the new integral kernel. We find that one can engineer this kernel such that the overall rate of decay is lowered by the addition of this noise term. We illustrate this technique for the case where the bare noise is described by a dephasing Pauli channel. We analytically solve this model and show that one can effectively double (or even triple) the length of the channel, while achieving the same fidelity, entanglement, and error threshold. We numerically verify this scheme can also be used to protect against thermal Markovian noise (at nonzero temperature), which models spontaneous emission and excitation processes. A physical interpretation of this scheme is discussed, whereby the added generalized-Markovian noise causes the system to become periodically decoupled from the background Markovian noise.

Survival probability of a local excitation in a non-Markovian environment: Survival collapse, Zeno and anti-Zeno effects

International Nuclear Information System (INIS)

Rufeil-Fiori, E.; Pastawski, H.M.

2009-01-01

The decay dynamics of a local excitation interacting with a non-Markovian environment, modeled by a semi-infinite tight-binding chain, is exactly evaluated. We identify distinctive regimes for the dynamics. Sequentially: (i) early quadratic decay of the initial-state survival probability, up to a spreading time t S , (ii) exponential decay described by a self-consistent Fermi Golden Rule, and (iii) asymptotic behavior governed by quantum diffusion through the return processes, leading to an inverse power law decay. At this last cross-over time t R a survival collapse becomes possible. This could reduce the survival probability by several orders of magnitude. The cross-over times t S and t R allow to assess the range of applicability of the Fermi Golden Rule and give the conditions for the observation of the Zeno and anti-Zeno effect.

Recursive approach for non-Markovian time-convolutionless master equations

Science.gov (United States)

Gasbarri, G.; Ferialdi, L.

2018-02-01

We consider a general open system dynamics and we provide a recursive method to derive the associated non-Markovian master equation in a perturbative series. The approach relies on a momenta expansion of the open system evolution. Unlike previous perturbative approaches of this kind, the method presented in this paper provides a recursive definition of each perturbative term. Furthermore, we give an intuitive diagrammatic description of each term of the series, which provides a useful analytical tool to build them and to derive their structure in terms of commutators and anticommutators. We eventually apply our formalism to the evolution of the observables of the reduced system, by showing how the method can be applied to the adjoint master equation, and by developing a diagrammatic description of the associated series.

Ultrafast dynamics of laser-pulse excited semiconductors: non-Markovian quantum kinetic equations with nonequilibrium correlations

Directory of Open Access Journals (Sweden)

V.V.Ignatyuk

2004-01-01

Full Text Available Non-Markovian kinetic equations in the second Born approximation are derived for a two-zone semiconductor excited by a short laser pulse. Both collision dynamics and running nonequilibrium correlations are taken into consideration. The energy balance and relaxation of the system to equilibrium are discussed. Results of numerical solution of the kinetic equations for carriers and phonons are presented.

Superdiffusion in a non-Markovian random walk model with a Gaussian memory profile

Science.gov (United States)

Borges, G. M.; Ferreira, A. S.; da Silva, M. A. A.; Cressoni, J. C.; Viswanathan, G. M.; Mariz, A. M.

2012-09-01

Most superdiffusive Non-Markovian random walk models assume that correlations are maintained at all time scales, e.g., fractional Brownian motion, Lévy walks, the Elephant walk and Alzheimer walk models. In the latter two models the random walker can always "remember" the initial times near t = 0. Assuming jump size distributions with finite variance, the question naturally arises: is superdiffusion possible if the walker is unable to recall the initial times? We give a conclusive answer to this general question, by studying a non-Markovian model in which the walker's memory of the past is weighted by a Gaussian centered at time t/2, at which time the walker had one half the present age, and with a standard deviation σt which grows linearly as the walker ages. For large widths we find that the model behaves similarly to the Elephant model, but for small widths this Gaussian memory profile model behaves like the Alzheimer walk model. We also report that the phenomenon of amnestically induced persistence, known to occur in the Alzheimer walk model, arises in the Gaussian memory profile model. We conclude that memory of the initial times is not a necessary condition for generating (log-periodic) superdiffusion. We show that the phenomenon of amnestically induced persistence extends to the case of a Gaussian memory profile.

Exact master equations for the non-Markovian decay of a qubit

International Nuclear Information System (INIS)

Vacchini, Bassano; Breuer, Heinz-Peter

2010-01-01

Exact master equations describing the decay of a two-state system into a structured reservoir are constructed. By employing the exact solution for the model, analytical expressions are determined for the memory kernel of the Nakajima-Zwanzig master equation and for the generator of the corresponding time-convolutionless master equation. This approach allows an explicit comparison of the convergence behavior of the corresponding perturbation expansions. Moreover, the structure of widely used phenomenological master equations with a memory kernel may be incompatible with a nonperturbative treatment of the underlying microscopic model. Several physical implications of the results on the microscopic analysis and the phenomenological modeling of non-Markovian quantum dynamics of open systems are discussed.

Non-Markovian modification of the golden rule rate expression

International Nuclear Information System (INIS)

Basilevsky, M. V.; Davidovich, G. V.; Titov, S. V.; Voronin, A. I.

2006-01-01

The reformulation of the standard golden rule approach considered in this paper for treating reactive tunneling reduces the computation of the reaction rate to a derivation of band shapes for energy levels of reactant and product states. This treatment is based on the assumption that the medium environment is actively involved as a partner in the energy exchange with the reactive subsystem but its reorganization effect is negligible. Starting from the quantum relaxation equation for the density matrix, the required band shapes are represented in terms of the spectral density function, exhibiting the continuum spectrum inherent to the interaction between the reactants and the medium in the total reactive system. The simplest Lorentzian spectral bands, obtained under Redfield approximation, proved to be unsatisfactory because they produced a divergent rate expression at low temperature. The problem is resolved by invoking a refined spectral band shape, which behaves as Lorentzian one at the band center but decays exponentially at its tails. The corresponding closed non-Markovian rate expression is derived and investigated taking as an example the photochemical H-transfer reaction between fluorene and acridine proceeding in the fluorene molecular crystal. The kinetics in this reactive system was thoroughly studied experimentally in a wide temperature range [B. Prass et al., Ber. Bunsenges. Phys. Chem. 102, 498 (1998)

Manifestations and mechanisms of non-targeted effects of ionizing radiation

International Nuclear Information System (INIS)

Wright, Eric G.

2010-01-01

A well-established radiobiological paradigm is that the biological effects of ionizing radiation occur in irradiated cells as a consequence of the DNA damage they incur. However, many observations of, so-called, non-targeted effects indicate that genetic alterations are not restricted to directly irradiated cells. Non-targeted effects are responses exhibited by non-irradiated cells that are the descendants of irradiated cells (radiation-induced genomic instability) or by cells that have communicated with irradiated cells (radiation-induced bystander effects). Radiation-induced genomic instability is characterized by chromosomal abnormalities, gene mutations and cell death. Similar effects, as well as responses that may be regarded as protective, have been attributed to bystander mechanisms. The majority of studies to date have used in vitro systems but some non-targeted effects have been demonstrated in vivo and there is also evidence for radiation-induced instability in the mammalian germ line. However, there may be situations where radiation-induced genomic instability in vivo may not necessarily identify genomically unstable somatic cells but the manifestation of responses to ongoing production of damaging signals generated by genotype-dependent mechanisms having properties in common with inflammatory processes. Non-targeted mechanisms have significant implications for understanding mechanisms of radiation action but the current state of knowledge does not permit definitive statements about whether these phenomena have implications for assessing radiation risk.

Spherical particle Brownian motion in viscous medium as non-Markovian random process

International Nuclear Information System (INIS)

Morozov, Andrey N.; Skripkin, Alexey V.

2011-01-01

The Brownian motion of a spherical particle in an infinite medium is described by the conventional methods and integral transforms considering the entrainment of surrounding particles of the medium by the Brownian particle. It is demonstrated that fluctuations of the Brownian particle velocity represent a non-Markovian random process. The features of Brownian motion in short time intervals and in small displacements are considered. -- Highlights: → Description of Brownian motion considering the entrainment of medium is developed. → We find the equations for statistical characteristics of impulse fluctuations. → Brownian motion at small time intervals is considered. → Theoretical results and experimental data are compared.

Fitting Markovian binary trees using global and individual demographic data

OpenAIRE

Hautphenne, Sophie; Massaro, Melanie; Turner, Katharine

2017-01-01

We consider a class of branching processes called Markovian binary trees, in which the individuals lifetime and reproduction epochs are modeled using a transient Markovian arrival process (TMAP). We estimate the parameters of the TMAP based on population data containing information on age-specific fertility and mortality rates. Depending on the degree of detail of the available data, a weighted non-linear regression method or a maximum likelihood method is applied. We discuss the optimal choi...

Phonon-induced dissipation and decoherence in solid-state quantum devices: Markovian versus non-Markovian treatments

Science.gov (United States)

Iotti, Rita Claudia; Rossi, Fausto

2017-12-01

Microscopic modeling of electronic phase coherence versus energy dissipation plays a crucial role in the design and optimization of new-generation electronic quantum nanodevices, like quantum-cascade light sources and quantum logic gates; in this context, non-Markovian density-matrix approaches are widely used simulation strategies. Here we show that such methods, along with valuable virtues, in some circumstances may exhibit potential limitations that need to be taken into account for a reliable description of quantum materials and related devices. More specifically, extending the analysis recently proposed in [EPL 112, 67005 (2015)] to high temperatures and degenerate conditions, we show that the usual mean-field treatment - employed to derive quantum-kinetic equations - in some cases may lead to anomalous results, characterized by decoherence suppression and positivity violations. By means of a simple two-level model, we show that such unexpected behaviors may affect zero-dimensional electronic systems coupled to dispersionless phonon modes, while such anomalies are expected to play a negligible role in nanosystems with higher dimensionality; these limitations are found to be significant in the low-density and low-temperature limit, while in the degenerate and/or finite-temperature regime - typical of many state-of-the-art quantum devices - their impact is strongly reduced.

Quantum Darwinism and non-Markovian dissipative dynamics from quantum phases of the spin-1/2 X X model

Science.gov (United States)

Giorgi, Gian Luca; Galve, Fernando; Zambrini, Roberta

2015-08-01

Quantum Darwinism explains the emergence of a classical description of objects in terms of the creation of many redundant registers in an environment containing their classical information. This amplification phenomenon, where only classical information reaches the macroscopic observer and through which different observers can agree on the objective existence of such object, has been revived lately for several types of situations, successfully explaining classicality. We explore quantum Darwinism in the setting of an environment made of two level systems which are initially prepared in the ground state of the XX model, which exhibits different phases; we find that the different phases have different abilities to redundantly acquire classical information about the system, the "ferromagnetic phase" being the only one able to complete quantum Darwinism. At the same time we relate this ability to how non-Markovian the system dynamics is, based on the interpretation that non-Markovian dynamics is associated with backflow of information from environment to system, thus spoiling the information transfer needed for Darwinism. Finally, we explore mixing of bath registers by allowing a small interaction among them, finding that this spoils the stored information as previously found in the literature.

Non-Markovian decay of a three-level cascade atom in a structured reservoir

International Nuclear Information System (INIS)

Dalton, B.J.; Garraway, B.M.

2003-01-01

The dynamics of a three-level atom in a cascade (or ladder) configuration with both transitions coupled to a single structured reservoir of quantized electromagnetic field modes is treated using Laplace transform methods applied to the coupled amplitude equations. In this system two-photon excitation of the reservoir occurs, and both sequences for emitting the two photons are allowed and included in the theory. An integral equation is found to govern the complex amplitudes of interest. It is shown that the dynamics of the atomic system is completely determined in terms of reservoir structure functions, which are products of the mode density with the coupling constant squared. This dependence on reservoir structure functions rather than on the mode density or coupling constants alone, shows that it may be possible to extend pseudomode theory to treat multiphoton excitation of a structured reservoir--pseudomodes being introduced in one-one correspondence with the poles of reservoir structure functions in the complex frequency plane. A general numerical method for solving the integral equations based on discretizing frequency space, and applicable to different structured reservoirs such as high-Q cavities and photonic band-gap systems, is presented. An application to a high-Q-cavity case with identical Lorentzian reservoir structure functions is made, and the non-Markovian decay of the excited state shown. A formal solution to the integral equations in terms of right and left eigenfunctions of a non-Hermitian kernel is also given. The dynamics of the cascade atom, with the two transitions coupled to two separate structured reservoirs of quantized electromagnetic field modes, is treated similarly to the single structured reservoir situation. Again the dynamics only depends on reservoir structure functions. As only one sequence of emitting the two photons now occurs, the integral equation for the amplitudes can be solved analytically. The non-Markovian decay of the

Condition-based maintenance effectiveness for series–parallel power generation system—A combined Markovian simulation model

International Nuclear Information System (INIS)

Azadeh, A.; Asadzadeh, S.M.; Salehi, N.; Firoozi, M.

2015-01-01

Condition-based maintenance (CBM) is an increasingly applicable policy in the competitive marketplace as a means of improving equipment reliability and efficiency. Not only has maintenance a close relationship with safety but its costs also make it even more attractive issue for researchers. This study proposes a model to evaluate the effectiveness of CBM policy compared to two other maintenance policies: Corrective Maintenance (CM) and Preventive Maintenance (PM). Maintenance policies are compared through two system performance indicators: reliability and cost. To estimate the reliability and costs of the system, the proposed Markovian discrete-event simulation model is developed under each of these policies. The applicability and usefulness of the proposed Markovian simulation model is illustrated for a series–parallel power generation system. The simulated characteristics of CBM system include its prognostics efficiency to estimate remaining useful life of the equipment. Results show that with an efficient prognostics, CBM policy is an effective strategy compared to other maintenance strategies. - Highlights: • A model is developed to evaluate the effectiveness of CBM policy. • Maintenance policies are compared through reliability and cost. • A Markovian simulation model is developed. • A series–parallel power generation system is considered. • CBM is an effective strategy compared to others

Some performance measures for vacation models with a batch Markovian arrival process

Directory of Open Access Journals (Sweden)

Sadrac K. Matendo

1994-01-01

Full Text Available We consider a single server infinite capacity queueing system, where the arrival process is a batch Markovian arrival process (BMAP. Particular BMAPs are the batch Poisson arrival process, the Markovian arrival process (MAP, many batch arrival processes with correlated interarrival times and batch sizes, and superpositions of these processes. We note that the MAP includes phase-type (PH renewal processes and non-renewal processes such as the Markov modulated Poisson process (MMPP.

Optimized auxiliary representation of non-Markovian impurity problems by a Lindblad equation

International Nuclear Information System (INIS)

Dorda, A; Sorantin, M; Linden, W von der; Arrigoni, E

2017-01-01

We present a general scheme to address correlated nonequilibrium quantum impurity problems based on a mapping onto an auxiliary open quantum system of small size. The infinite fermionic reservoirs of the original system are thereby replaced by a small number N B of noninteracting auxiliary bath sites whose dynamics are described by a Lindblad equation, which can then be exactly solved by numerical methods such as Lanczos or matrix-product states. The mapping becomes exponentially exact with increasing N B , and is already quite accurate for small N B . Due to the presence of the intermediate bath sites, the overall dynamics acting on the impurity site is non-Markovian. While in previous work we put the focus on the manybody solution of the associated Lindblad problem, here we discuss the mapping scheme itself, which is an essential part of the overall approach. On the one hand, we provide technical details together with an in-depth discussion of the employed algorithms, and on the other hand, we present a detailed convergence study. The latter clearly demonstrates the above-mentioned exponential convergence of the procedure with increasing N B . Furthermore, the influence of temperature and an external bias voltage on the reservoirs is investigated. The knowledge of the particular convergence behavior is of great value to assess the applicability of the scheme to certain physical situations. Moreover, we study different geometries for the auxiliary system. On the one hand, this is of importance for advanced manybody solution techniques such as matrix product states which work well for short-ranged couplings, and on the other hand, it allows us to gain more insights into the underlying mechanisms when mapping non-Markovian reservoirs onto Lindblad-type impurity problems. Finally, we present results for the spectral function of the Anderson impurity model in and out of equilibrium and discuss the accuracy obtained with the different geometries of the auxiliary system

Stochastic parameterizing manifolds and non-Markovian reduced equations stochastic manifolds for nonlinear SPDEs II

CERN Document Server

Chekroun, Mickaël D; Wang, Shouhong

2015-01-01

In this second volume, a general approach is developed to provide approximate parameterizations of the "small" scales by the "large" ones for a broad class of stochastic partial differential equations (SPDEs). This is accomplished via the concept of parameterizing manifolds (PMs), which are stochastic manifolds that improve, for a given realization of the noise, in mean square error the partial knowledge of the full SPDE solution when compared to its projection onto some resolved modes. Backward-forward systems are designed to give access to such PMs in practice. The key idea consists of representing the modes with high wave numbers as a pullback limit depending on the time-history of the modes with low wave numbers. Non-Markovian stochastic reduced systems are then derived based on such a PM approach. The reduced systems take the form of stochastic differential equations involving random coefficients that convey memory effects. The theory is illustrated on a stochastic Burgers-type equation.

Power-law tails and non-Markovian dynamics in open quantum systems: An exact solution from Keldysh field theory

Science.gov (United States)

Chakraborty, Ahana; Sensarma, Rajdeep

2018-03-01

The Born-Markov approximation is widely used to study the dynamics of open quantum systems coupled to external baths. Using Keldysh formalism, we show that the dynamics of a system of bosons (fermions) linearly coupled to a noninteracting bosonic (fermionic) bath falls outside this paradigm if the bath spectral function has nonanalyticities as a function of frequency. In this case, we show that the dissipative and noise kernels governing the dynamics have distinct power-law tails. The Green's functions show a short-time "quasi"-Markovian exponential decay before crossing over to a power-law tail governed by the nonanalyticity of the spectral function. We study a system of bosons (fermions) hopping on a one-dimensional lattice, where each site is coupled linearly to an independent bath of noninteracting bosons (fermions). We obtain exact expressions for the Green's functions of this system, which show power-law decay ˜|t - t'|-3 /2 . We use these to calculate the density and current profile, as well as unequal-time current-current correlators. While the density and current profiles show interesting quantitative deviations from Markovian results, the current-current correlators show qualitatively distinct long-time power-law tails |t - t'|-3 characteristic of non-Markovian dynamics. We show that the power-law decays survive in the presence of interparticle interaction in the system, but the crossover time scale is shifted to larger values with increasing interaction strength.

Non-Markovian response of ultrafast coherent electronic ring currents in chiral aromatic molecules in a condensed phase

International Nuclear Information System (INIS)

Mineo, H.; Lin, S. H.; Fujimura, Y.; Xu, J.; Xu, R. X.; Yan, Y. J.

2013-01-01

Results of a theoretical study on non-Markov response for femtosecond laser-driven coherent ring currents in chiral aromatic molecules embedded in a condensed phase are presented. Coherent ring currents are generated by coherent excitation of a pair of quasi-degenerated π-electronic excited states. The coherent electronic dynamical behaviors are strongly influenced by interactions between the electronic system and phonon bath in a condensed phase. Here, the bath correlation time is not instantaneous but should be taken to be a finite time in ultrashort time-resolved experiments. In such a case, Markov approximation breaks down. A hierarchical master equation approach for an improved semiclassical Drude dissipation model was adopted to examine the non-Markov effects on ultrafast coherent electronic ring currents of (P)-2,2 ′ -biphenol in a condensed phase. Time evolution of the coherent ring current derived in the hierarchical master equation approach was calculated and compared with those in the Drude model in the Markov approximation and in the static limit. The results show how non-Markovian behaviors in quantum beat signals of ring currents depend on the Drude bath damping constant. Effects of temperatures on ultrafast coherent electronic ring currents are also clarified

A Dynamical Theory of Markovian Diffusion

OpenAIRE

Davidson, Mark

2001-01-01

A dynamical treatment of Markovian diffusion is presented and several applications discussed. The stochastic interpretation of quantum mechanics is considered within this framework. A model for Brownian movement which includes second order quantum effects is derived.

On the validity of non-Markovian master equation approaches for the entanglement dynamics of two-qubit systems

Energy Technology Data Exchange (ETDEWEB)

Ferraro, E; Scala, M; Napoli, A [CNISM and Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo, via Archirafi 36, 90123 Palermo (Italy); Migliore, R, E-mail: ferraro@fisica.unipa.i, E-mail: matteo.scala@fisica.unipa.i [CNR-INFM, Research Unit CNISM of Palermo, via Archirafi 36, 90123 Palermo (Italy)

2010-09-01

In the framework of the dissipative dynamics of coupled qubits interacting with independent reservoirs, a comparison between non-Markovian master equation techniques and an exact solution is presented here. We study various regimes in order to find the limits of validity of the Nakajima-Zwanzig and the time-convolutionless master equations in the description of the entanglement dynamics. A comparison between the performances of the concurrence and the negativity as entanglement measures for the system under study is also presented.

Joint Probability Distributions for a Class of Non-Markovian Processes

OpenAIRE

Baule, A.; Friedrich, R.

2004-01-01

We consider joint probability distributions for the class of coupled Langevin equations introduced by Fogedby [H.C. Fogedby, Phys. Rev. E 50, 1657 (1994)]. We generalize well-known results for the single time probability distributions to the case of N-time joint probability distributions. It is shown that these probability distribution functions can be obtained by an integral transform from distributions of a Markovian process. The integral kernel obeys a partial differential equation with fr...

Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations (II): thrombocytopenia and skin manifestations.

Science.gov (United States)

Cervera, R; Tektonidou, M G; Espinosa, G; Cabral, A R; González, E B; Erkan, D; Vadya, S; Adrogué, H E; Solomon, M; Zandman-Goddard, G; Shoenfeld, Y

2011-02-01

The objectives of the 'Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations' were to assess the clinical utility of the international consensus statement on classification criteria and treatment guidelines for the catastrophic APS, to identify and grade the studies that analyze the relationship between the antiphospholipid antibodies and the non-criteria APS manifestations, and to present the current evidence regarding the accuracy of these non-criteria APS manifestations for the detection of patients with APS. This article summarizes the studies analyzed on thrombocytopenia and skin manifestations, and presents the recommendations elaborated by the Task Force after this analysis.

The Synthesis of a Hardware Scheduler for Non-Manifest Loops

NARCIS (Netherlands)

Mansour, O.; Molenkamp, Egbert; Krol, Th.

This paper addresses the hardware implementation of a dynamic scheduler for non-manifest data dependent periodic loops. Static scheduling techniques which are known to give near optimal scheduling-solutions for manifest loops, fail at scheduling non-manifest loops, since they lack the run time

Asymptotic propagators and trajectories in plasma turbulence theory. The importance of irreversibility, asymptoticity and non-Markovian terms

International Nuclear Information System (INIS)

Misguich, J.H.

1978-09-01

The physical meaning of perturbed trajectories in turbulent fields is analysed. Special care is devoted to the asymptotic description of average trajectories for long time intervals, as occuring in many recent plasma turbulence theories. Equivalence is proved between asymptotic average trajectories described as well (i) by the propagators V(t,t-tau) for retrodiction and Wsub(J)(t,t+tau) for prediction, and (ii) by the long time secular behavior of the solution of the equations of motion. This confirms the equivalence between perturbed orbit theories and renormalized theories, including non-Markovian contributions

Data-based Non-Markovian Model Inference

Science.gov (United States)

Ghil, Michael

2015-04-01

This talk concentrates on obtaining stable and efficient data-based models for simulation and prediction in the geosciences and life sciences. The proposed model derivation relies on using a multivariate time series of partial observations from a large-dimensional system, and the resulting low-order models are compared with the optimal closures predicted by the non-Markovian Mori-Zwanzig formalism of statistical physics. Multilayer stochastic models (MSMs) are introduced as both a very broad generalization and a time-continuous limit of existing multilevel, regression-based approaches to data-based closure, in particular of empirical model reduction (EMR). We show that the multilayer structure of MSMs can provide a natural Markov approximation to the generalized Langevin equation (GLE) of the Mori-Zwanzig formalism. A simple correlation-based stopping criterion for an EMR-MSM model is derived to assess how well it approximates the GLE solution. Sufficient conditions are given for the nonlinear cross-interactions between the constitutive layers of a given MSM to guarantee the existence of a global random attractor. This existence ensures that no blow-up can occur for a very broad class of MSM applications. The EMR-MSM methodology is first applied to a conceptual, nonlinear, stochastic climate model of coupled slow and fast variables, in which only slow variables are observed. The resulting reduced model with energy-conserving nonlinearities captures the main statistical features of the slow variables, even when there is no formal scale separation and the fast variables are quite energetic. Second, an MSM is shown to successfully reproduce the statistics of a partially observed, generalized Lokta-Volterra model of population dynamics in its chaotic regime. The positivity constraint on the solutions' components replaces here the quadratic-energy-preserving constraint of fluid-flow problems and it successfully prevents blow-up. This work is based on a close

Protecting entanglement by adjusting the velocities of moving qubits inside non-Markovian environments

Science.gov (United States)

Mortezapour, Ali; Ahmadi Borji, Mahdi; Lo Franco, Rosario

2017-05-01

Efficient entanglement preservation in open quantum systems is a crucial scope towards a reliable exploitation of quantum resources. We address this issue by studying how two-qubit entanglement dynamically behaves when two atom qubits move inside two separated identical cavities. The moving qubits independently interact with their respective cavity. As a main general result, we find that under resonant qubit-cavity interaction the initial entanglement between two moving qubits remains closer to its initial value as time passes compared to the case of stationary qubits. In particular, we show that the initial entanglement can be strongly protected from decay by suitably adjusting the velocities of the qubits according to the non-Markovian features of the cavities. Our results supply a further way of preserving quantum correlations against noise with a natural implementation in cavity-QED scenarios and are straightforwardly extendable to many qubits for scalability.

Generation of long-living entanglement between two distant three-level atoms in non-Markovian environments.

Science.gov (United States)

Li, Chuang; Yang, Sen; Song, Jie; Xia, Yan; Ding, Weiqiang

2017-05-15

In this paper, a scheme for the generation of long-living entanglement between two distant Λ-type three-level atoms separately trapped in two dissipative cavities is proposed. In this scheme, two dissipative cavities are coupled to their own non-Markovian environments and two three-level atoms are driven by the classical fields. The entangled state between the two atoms is produced by performing Bell state measurement (BSM) on photons leaving the dissipative cavities. Using the time-dependent Schördinger equation, we obtain the analytical results for the evolution of the entanglement. It is revealed that, by manipulating the detunings of classical field, the long-living stationary entanglement between two atoms can be generated in the presence of dissipation.

Properties of quantum Markovian master equations

International Nuclear Information System (INIS)

Gorini, V.; Frigerio, A.; Verri, M.; Kossakowski, A.; Sudarshan, E.C.G.

1976-11-01

An essentially self-contained account is given of some general structural properties of the dynamics of quantum open Markovian systems. Some recent results regarding the problem of the classification of quantum Markovian master equations and the limiting conditions under which the dynamical evolution of a quantum open system obeys an exact semigroup law (weak coupling limit and singular coupling limit are reviewed). A general form of quantum detailed balance and its relation to thermal relaxation and to microreversibility is discussed

Mean square stabilization and mean square exponential stabilization of stochastic BAM neural networks with Markovian jumping parameters

International Nuclear Information System (INIS)

Ye, Zhiyong; Zhang, He; Zhang, Hongyu; Zhang, Hua; Lu, Guichen

2015-01-01

Highlights: •This paper introduces a non-conservative Lyapunov functional. •The achieved results impose non-conservative and can be widely used. •The conditions are easily checked by the Matlab LMI Tool Box. The desired state feedback controller can be well represented by the conditions. -- Abstract: This paper addresses the mean square exponential stabilization problem of stochastic bidirectional associative memory (BAM) neural networks with Markovian jumping parameters and time-varying delays. By establishing a proper Lyapunov–Krasovskii functional and combining with LMIs technique, several sufficient conditions are derived for ensuring exponential stabilization in the mean square sense of such stochastic BAM neural networks. In addition, the achieved results are not difficult to verify for determining the mean square exponential stabilization of delayed BAM neural networks with Markovian jumping parameters and impose less restrictive and less conservative than the ones in previous papers. Finally, numerical results are given to show the effectiveness and applicability of the achieved results

Deterministic quantum controlled-PHASE gates based on non-Markovian environments

Science.gov (United States)

Zhang, Rui; Chen, Tian; Wang, Xiang-Bin

2017-12-01

We study the realization of the quantum controlled-PHASE gate in an atom-cavity system beyond the Markovian approximation. The general description of the dynamics for the atom-cavity system without any approximation is presented. When the spectral density of the reservoir has the Lorentz form, by making use of the memory backflow from the reservoir, we can always construct the deterministic quantum controlled-PHASE gate between a photon and an atom, no matter the atom-cavity coupling strength is weak or strong. While, the phase shift in the output pulse hinders the implementation of quantum controlled-PHASE gates in the sub-Ohmic, Ohmic or super-Ohmic reservoirs.

Continued-fraction representation of the Kraus map for non-Markovian reservoir damping

Science.gov (United States)

van Wonderen, A. J.; Suttorp, L. G.

2018-04-01

Quantum dissipation is studied for a discrete system that linearly interacts with a reservoir of harmonic oscillators at thermal equilibrium. Initial correlations between system and reservoir are assumed to be absent. The dissipative dynamics as determined by the unitary evolution of system and reservoir is described by a Kraus map consisting of an infinite number of matrices. For all Laplace-transformed Kraus matrices exact solutions are constructed in terms of continued fractions that depend on the pair correlation functions of the reservoir. By performing factorizations in the Kraus map a perturbation theory is set up that conserves in arbitrary perturbative order both positivity and probability of the density matrix. The latter is determined by an integral equation for a bitemporal matrix and a finite hierarchy for Kraus matrices. In the lowest perturbative order this hierarchy reduces to one equation for one Kraus matrix. Its solution is given by a continued fraction of a much simpler structure as compared to the non-perturbative case. In the lowest perturbative order our non-Markovian evolution equations are applied to the damped Jaynes–Cummings model. From the solution for the atomic density matrix it is found that the atom may remain in the state of maximum entropy for a significant time span that depends on the initial energy of the radiation field.

Markovian approach: From Ising model to stochastic radiative transfer

International Nuclear Information System (INIS)

Kassianov, E.; Veron, D.

2009-01-01

The origin of the Markovian approach can be traced back to 1906; however, it gained explicit recognition in the last few decades. This overview outlines some important applications of the Markovian approach, which illustrate its immense prestige, respect, and success. These applications include examples in the statistical physics, astronomy, mathematics, computational science and the stochastic transport problem. In particular, the overview highlights important contributions made by Pomraning and Titov to the neutron and radiation transport theory in a stochastic medium with homogeneous statistics. Using simple probabilistic assumptions (Markovian approximation), they have introduced a simplified, but quite realistic, representation of the neutron/radiation transfer through a two-component discrete stochastic mixture. New concepts and methodologies introduced by these two distinguished scientists allow us to generalize the Markovian treatment to the stochastic medium with inhomogeneous statistics and demonstrate its improved predictive performance for the down-welling shortwave fluxes. (authors)

Adaptive resummation of Markovian quantum dynamics

International Nuclear Information System (INIS)

Lucas, Felix

2014-01-01

In this thesis we derive a highly convergent, nonperturbative expansion of Markovian open quantum dynamics. It is based on a splitting of the incoherent dynamics into periods of continuous evolution and abrupt jumps and attains its favorable convergence properties from an adaptive resummation of this so-called jump expansion. By means of the long-standing problems of spatial particle detection and Landau-Zener tunneling in the presence of dephasing, we show that this adaptive resummation technique facilitates new highly accurate analytic approximations of Markovian open systems. The open Landau-Zener model leads us to propose an efficient and robust incoherent control technique for the isomerization reaction of the visual pigment protein rhodopsin. Besides leading to approximate analytic descriptions of Markovian open quantum dynamics, the adaptive resummation of the jump expansion implies an efficient numerical simulation method. We spell out the corresponding numerical algorithm by means of Monte Carlo integration of the relevant terms in the jump expansion and demonstrate it in a set of paradigmatic open quantum systems.

Robust extended Kalman filter of discrete-time Markovian jump nonlinear system under uncertain noise

International Nuclear Information System (INIS)

Zhu, Jin; Park, Jun Hong; Lee, Kwan Soo; Spiryagin, Maksym

2008-01-01

This paper examines the problem of robust extended Kalman filter design for discrete -time Markovian jump nonlinear systems with noise uncertainty. Because of the existence of stochastic Markovian switching, the state and measurement equations of underlying system are subject to uncertain noise whose covariance matrices are time-varying or un-measurable instead of stationary. First, based on the expression of filtering performance deviation, admissible uncertainty of noise covariance matrix is given. Secondly, two forms of noise uncertainty are taken into account: Non- Structural and Structural. It is proved by applying game theory that this filter design is a robust mini-max filter. A numerical example shows the validity of the method

Cutaneous manifestations of non-Hodgkin's lymphoma.

Science.gov (United States)

Kumar, S S; Kuruvilla, M; Pai, G S; Dinesh, M

2003-01-01

Thirty-two confirmed cases of non -Hodgkin's lymphoma (NHL) were examined for cutaneous manifestations for a period of 2 years from November 1998 in KMC Hospital Attavar, Mangalore. Cutaneous manifestations in the study group were compared to a control group of 32 patients. Specific infiltrates were present in all (5/5) CTCL patients and one out of twenty-seven patients with low grade NHL. Morphologically they presented as papules, plaques, nodules and erythroderma. Infective conditions seen in the study group were superficial fungal (7/32) and viral infections (2/ 32). Non-infective conditions were acquired ichthyosis (10/32), generalised pruritus (5/32), insect bite reaction (1/32) and drug eruption (1/32). When compared to control patients only acquired ichthyosis and generalised pruritus were found to be statistically significant. The study group also showed changes due to chemotherapy like diffuse alopecia (24/29), bluish pigmentation of proximal part of nail (4/29), localised pigmentation of palms and soles (1 /29), diffuse pigmentation at injection site (1 /29), pigmentation at scar site (1 /29) and stomatitis (4/29).

Antiphospholipid antibodies and non-thrombotic manifestations of systemic lupus erythematosus.

Science.gov (United States)

İlgen, U; Yayla, M E; Ateş, A; Okatan, İ E; Yurteri, E U; Torgutalp, M; Keleşoğlu, A B D; Turgay, T M; Kınıklı, G

2018-04-01

Objectives The aim of this study was to investigate the association between antiphospholipid antibodies and non-thrombotic and non-gestational manifestations of systemic lupus erythematosus. Methods Systemic lupus erythematosus patients with persistently positive antiphospholipid antibodies or lupus anticoagulant were identified and grouped as systemic lupus erythematosus with antiphospholipid syndrome (SLE-APS), systemic lupus erythematosus with positive antiphospholipid antibodies/lupus anticoagulant without antiphospholipid syndrome (SLE-aPL), and systemic lupus erythematosus with negative aPLs (SLE-No aPL). Groups were compared in terms of non-thrombotic systemic lupus erythematosus manifestations and laboratory features retrospectively. Results A total of 150 systemic lupus erythematosus patients, 26 with SLE-APS, 25 with SLE-aPL, and 99 with SLE-No aPL, were identified. Livedo reticularis, neurologic involvement, and thrombocytopenia were more common in antiphospholipid antibody positive systemic lupus erythematosus cases. Malar rash, arthritis, and pleuritis were more common in the SLE-No aPL, SLE-APS, and SLE-aPL groups, respectively. Positivity rates and titers of specific antiphospholipid antibodies did not differ between the SLE-APS and SLE-aPL groups. Conclusions Presence of antiphospholipid syndrome or persistent antiphospholipid antibodies may be related to non-thrombotic and non-gestational systemic lupus erythematosus manifestations. Patients with systemic lupus erythematosus plus antiphospholipid syndrome and persistent antiphospholipid antibodies without antiphospholipid syndrome also differ in terms of systemic lupus erythematosus manifestations.

Semiclassical evolution of dissipative Markovian systems

International Nuclear Information System (INIS)

Ozorio de Almeida, A M; Rios, P de M; Brodier, O

2009-01-01

A semiclassical approximation for an evolving density operator, driven by a 'closed' Hamiltonian operator and 'open' Markovian Lindblad operators, is obtained. The theory is based on the chord function, i.e. the Fourier transform of the Wigner function. It reduces to an exact solution of the Lindblad master equation if the Hamiltonian operator is a quadratic function and the Lindblad operators are linear functions of positions and momenta. Initially, the semiclassical formulae for the case of Hermitian Lindblad operators are reinterpreted in terms of a (real) double phase space, generated by an appropriate classical double Hamiltonian. An extra 'open' term is added to the double Hamiltonian by the non-Hermitian part of the Lindblad operators in the general case of dissipative Markovian evolution. The particular case of generic Hamiltonian operators, but linear dissipative Lindblad operators, is studied in more detail. A Liouville-type equivariance still holds for the corresponding classical evolution in double phase space, but the centre subspace, which supports the Wigner function, is compressed, along with expansion of its conjugate subspace, which supports the chord function. Decoherence narrows the relevant region of double phase space to the neighbourhood of a caustic for both the Wigner function and the chord function. This difficulty is avoided by a propagator in a mixed representation, so that a further 'small-chord' approximation leads to a simple generalization of the quadratic theory for evolving Wigner functions

Markovian dynamics on complex reaction networks

Energy Technology Data Exchange (ETDEWEB)

Goutsias, J., E-mail: goutsias@jhu.edu; Jenkinson, G., E-mail: jenkinson@jhu.edu

2013-08-10

Complex networks, comprised of individual elements that interact with each other through reaction channels, are ubiquitous across many scientific and engineering disciplines. Examples include biochemical, pharmacokinetic, epidemiological, ecological, social, neural, and multi-agent networks. A common approach to modeling such networks is by a master equation that governs the dynamic evolution of the joint probability mass function of the underlying population process and naturally leads to Markovian dynamics for such process. Due however to the nonlinear nature of most reactions and the large size of the underlying state-spaces, computation and analysis of the resulting stochastic population dynamics is a difficult task. This review article provides a coherent and comprehensive coverage of recently developed approaches and methods to tackle this problem. After reviewing a general framework for modeling Markovian reaction networks and giving specific examples, the authors present numerical and computational techniques capable of evaluating or approximating the solution of the master equation, discuss a recently developed approach for studying the stationary behavior of Markovian reaction networks using a potential energy landscape perspective, and provide an introduction to the emerging theory of thermodynamic analysis of such networks. Three representative problems of opinion formation, transcription regulation, and neural network dynamics are used as illustrative examples.

Markovian dynamics on complex reaction networks

International Nuclear Information System (INIS)

Goutsias, J.; Jenkinson, G.

2013-01-01

Complex networks, comprised of individual elements that interact with each other through reaction channels, are ubiquitous across many scientific and engineering disciplines. Examples include biochemical, pharmacokinetic, epidemiological, ecological, social, neural, and multi-agent networks. A common approach to modeling such networks is by a master equation that governs the dynamic evolution of the joint probability mass function of the underlying population process and naturally leads to Markovian dynamics for such process. Due however to the nonlinear nature of most reactions and the large size of the underlying state-spaces, computation and analysis of the resulting stochastic population dynamics is a difficult task. This review article provides a coherent and comprehensive coverage of recently developed approaches and methods to tackle this problem. After reviewing a general framework for modeling Markovian reaction networks and giving specific examples, the authors present numerical and computational techniques capable of evaluating or approximating the solution of the master equation, discuss a recently developed approach for studying the stationary behavior of Markovian reaction networks using a potential energy landscape perspective, and provide an introduction to the emerging theory of thermodynamic analysis of such networks. Three representative problems of opinion formation, transcription regulation, and neural network dynamics are used as illustrative examples

The gentilionic theory for quarks: Manifestly confining for quarks and manifestly non-coalescent for hadrons

International Nuclear Information System (INIS)

Cattani, M.S.D.

1987-01-01

It's shown that the gentilionic theory for quarks is manifestly confining for quarks and manifestly non-coalescent for hadrons, and that these properties are rigorously deduced only from first principles. To prove them no arguments involving the intrinsic nature of gentileons or dynamical hypothesis are necessary to be adopted. It's also shown that, in the context of the quantum field theory, gentileous can be taken approximately as fermions and that the usual quantum chromodynamics can be used to calculate the properties of gentilionic hadrons. (Author) [pt

Non-Markovian closure models for large eddy simulations using the Mori-Zwanzig formalism

Science.gov (United States)

Parish, Eric J.; Duraisamy, Karthik

2017-01-01

This work uses the Mori-Zwanzig (M-Z) formalism, a concept originating from nonequilibrium statistical mechanics, as a basis for the development of coarse-grained models of turbulence. The mechanics of the generalized Langevin equation (GLE) are considered, and insight gained from the orthogonal dynamics equation is used as a starting point for model development. A class of subgrid models is considered which represent nonlocal behavior via a finite memory approximation [Stinis, arXiv:1211.4285 (2012)], the length of which is determined using a heuristic that is related to the spectral radius of the Jacobian of the resolved variables. The resulting models are intimately tied to the underlying numerical resolution and are capable of approximating non-Markovian effects. Numerical experiments on the Burgers equation demonstrate that the M-Z-based models can accurately predict the temporal evolution of the total kinetic energy and the total dissipation rate at varying mesh resolutions. The trajectory of each resolved mode in phase space is accurately predicted for cases where the coarse graining is moderate. Large eddy simulations (LESs) of homogeneous isotropic turbulence and the Taylor-Green Vortex show that the M-Z-based models are able to provide excellent predictions, accurately capturing the subgrid contribution to energy transfer. Last, LESs of fully developed channel flow demonstrate the applicability of M-Z-based models to nondecaying problems. It is notable that the form of the closure is not imposed by the modeler, but is rather derived from the mathematics of the coarse graining, highlighting the potential of M-Z-based techniques to define LES closures.

Stochastic stability analysis for delayed neural networks of neutral type with Markovian jump parameters

International Nuclear Information System (INIS)

Lou Xuyang; Cui Baotong

2009-01-01

In this paper, the problem of stochastic stability for a class of delayed neural networks of neutral type with Markovian jump parameters is investigated. The jumping parameters are modelled as a continuous-time, discrete-state Markov process. A sufficient condition guaranteeing the stochastic stability of the equilibrium point is derived for the Markovian jumping delayed neural networks (MJDNNs) with neutral type. The stability criterion not only eliminates the differences between excitatory and inhibitory effects on the neural networks, but also can be conveniently checked. The sufficient condition obtained can be essentially solved in terms of linear matrix inequality. A numerical example is given to show the effectiveness of the obtained results.

Sensitivity Analysis Based on Markovian Integration by Parts Formula

Directory of Open Access Journals (Sweden)

Yongsheng Hang

2017-10-01

Full Text Available Sensitivity analysis is widely applied in financial risk management and engineering; it describes the variations brought by the changes of parameters. Since the integration by parts technique for Markov chains is well developed in recent years, in this paper we apply it for computation of sensitivity and show the closed-form expressions for two commonly-used time-continuous Markovian models. By comparison, we conclude that our approach outperforms the existing technique of computing sensitivity on Markovian models.

Monte Carlo simulation of fully Markovian stochastic geometries

International Nuclear Information System (INIS)

Lepage, Thibaut; Delaby, Lucie; Malvagi, Fausto; Mazzolo, Alain

2010-01-01

The interest in resolving the equation of transport in stochastic media has continued to increase these last years. For binary stochastic media it is often assumed that the geometry is Markovian, which is never the case in usual environments. In the present paper, based on rigorous mathematical theorems, we construct fully two-dimensional Markovian stochastic geometries and we study their main properties. In particular, we determine a percolation threshold p c , equal to 0.586 ± 0.0015 for such geometries. Finally, Monte Carlo simulations are performed through these geometries and the results compared to homogeneous geometries. (author)

On the application of semi-Markovian processes to the unavailability analysis of majority voting protective systems

International Nuclear Information System (INIS)

Frutuoso e Melo, Paulo Fernando Ferreira

1992-01-01

In this work the application of semi-Markovian processes to the unavailability analysis of majority voting protective systems is discussed aiming at: modeling two problems that, possess practical relevance: explicit consideration of test intervals and possibility of including nonexponential repair times. Initially, protective systems up to 5 channels are modeled considering intervals between tests by means of a Markovian model in or.der to take into account the possibility of high demand rates. This model is a new extension of previous ones already published in the literature. The above mentioned Markovian model allows for considering either that the failure of a single channel is re by a real system demand or, alternatively, the failure is revealed only when k channels are found failed. Practical implications of this policies are important as they allow for different system actuation policies to be discussed and evaluated. A computer co de named RAMPSMM has been written in order to perform the aforementioned analysis. Results for different system configurations are shown and compared to published results concerning one and two channels. Those results agree adequately and the effect of higher demand rates on the systems is acknowledged. Next, a new semi-Markovian model for the the intervals between tests is discussed. The reason for employing it is that it describes a time interval that is constant, so that its describing process is not Markovian anymore. The model takes into account the influence of different parameters and repair policies as, for example, demand rate (considering the possibility of test overrides), staggered and sequential test policies and so on. l' Another consideration is made concerning the possibility of nonexponential ,- repair times. These kind of repair times are modeled by means of negative binomial distributions which correspond to discretized gamma densities assumed for the repair times. A second computer code named RAMPSSM has been

Comparison of Oral Manifestations of Diabetic and Non-Diabetic Uremic Patients Undergoing Hemodialysis

Directory of Open Access Journals (Sweden)

Seyed Javad Kia

2014-06-01

Full Text Available Background & Objectives: Chronic renal failure (CRF, also known as chronic kidney disease, caused by devastated nephron mass of the kidney results in uremia. Hypertension, diabetes mellitus and glomerulonephritis are common etiologic factors of CRF. This condition causes miscellaneous oral manifestations especially in diabetic patients. The aim of this study was to comparison oral manifestations of diabetic and non-diabetic uremic patients undergoing hemodialysis.   Methods: A total of 95 patients who undergoing hemodialysis in Razi hospital in Rasht city participated in this descriptive analytical study. Patients were divided into two diabetic and non- diabetic groups. Oral cavity examinations were done by latex gloves and single use mirror. Objective and subjective oral manifestations such as xerostomia, bad taste, mucosal pain, uremic odor, coating tongue, petechial, purpura, pale oral mucosa, ulcer, dental erosion and candida infection were recorded in questionnaire. After gathering of information, the data were analyzed by SPSS 15 software using t-test and chi square statistical test.   Results: About 60% of patients (57 person were men and 40 % (38 person were women. The mean age of patients was 48 years (range of 20 -76 years. Common subjective oral manifestation in both groups was xerostomia and most common objective oral manifestations were pale oral mucosa, uremic odor and coating tongue respectively. The DMFT index in diabetic group was significantly higher (17.3±7.63 than non-diabetic patients (12.4±8.26. There was no significant statistical correlation between the time of dialysis, number of dialysis appointment during the week and objective and subjective oral manifestations in two groups.   Conclusion: Although, the present study has shown an increase in oral manifestations in diabetic patients undergoing hemodialysis relative to non-diabetic group, but this increase was not statistically significant. On the other hand

Signaling pathways underpinning the manifestations of ionizing radiation-induced bystander effects.

Science.gov (United States)

Hamada, Nobuyuki; Maeda, Munetoshi; Otsuka, Kensuke; Tomita, Masanori

2011-06-01

For nearly a century, ionizing radiation has been indispensable to medical diagnosis. Furthermore, various types of electromagnetic and particulate radiation have also been used in cancer therapy. However, the biological mechanism of radiation action remains incompletely understood. In this regard, a rapidly growing body of experimental evidence indicates that radiation exposure induces biological effects in cells whose nucleus has not been irradiated. This phenomenon termed the 'non-targeted effects' challenges the long-held tenet that radiation traversal through the cell nucleus is a prerequisite to elicit genetic damage and biological responses. The non-targeted effects include biological effects in cytoplasm-irradiated cells, bystander effects that arise in non-irradiated cells having received signals from irradiated cells, and genomic instability occurring in the progeny of irradiated cells. Such non-targeted responses are interrelated, and the bystander effect is further related with an adaptive response that manifests itself as the attenuated stressful biological effects of acute high-dose irradiation in cells that have been pre-exposed to low-dose or low-dose-rate radiation. This paper reviews the current body of knowledge about the bystander effect with emphasis on experimental approaches, in vitro and in vivo manifestations, radiation quality dependence, temporal and spatial dependence, proposed mechanisms, and clinical implications. Relations of bystander responses with the effects in cytoplasm-irradiated cells, genomic instability and adaptive response will also be briefly discussed.

Memory loss process and non-Gibbsian equilibrium solutions of master equations

International Nuclear Information System (INIS)

Cataldo, H.M.; Hernandez, E.S.

1988-01-01

The phonon dynamics of a harmonic oscillator coupled to a steady reservoir is studied. In the Markovian limit, the equilibrium is reached through a progressive loss of memory process which involves the moments of the initial distribution. The relationship to the non-Markovian equations of motion and its resolvent poles is settled. As a particular model of the coupling mechanism is adopted, the possibility of non-Gibbsian equilibrium distribution arises, which is analyzed focusing upon the dependence of various parameters of the system on an effective equilibrium temperature

Coarse-grained representation of the quasi adiabatic propagator path integral for the treatment of non-Markovian long-time bath memory

Science.gov (United States)

Richter, Martin; Fingerhut, Benjamin P.

2017-06-01

The description of non-Markovian effects imposed by low frequency bath modes poses a persistent challenge for path integral based approaches like the iterative quasi-adiabatic propagator path integral (iQUAPI) method. We present a novel approximate method, termed mask assisted coarse graining of influence coefficients (MACGIC)-iQUAPI, that offers appealing computational savings due to substantial reduction of considered path segments for propagation. The method relies on an efficient path segment merging procedure via an intermediate coarse grained representation of Feynman-Vernon influence coefficients that exploits physical properties of system decoherence. The MACGIC-iQUAPI method allows us to access the regime of biological significant long-time bath memory on the order of hundred propagation time steps while retaining convergence to iQUAPI results. Numerical performance is demonstrated for a set of benchmark problems that cover bath assisted long range electron transfer, the transition from coherent to incoherent dynamics in a prototypical molecular dimer and excitation energy transfer in a 24-state model of the Fenna-Matthews-Olson trimer complex where in all cases excellent agreement with numerically exact reference data is obtained.

Exact decoherence dynamics of a single-mode optical field

International Nuclear Information System (INIS)

An, J.-H.; Yeo Ye; Oh, C.H.

2009-01-01

We apply the influence-functional method of Feynman and Vernon to the study of a single-mode optical field that interacts with an environment at zero temperature. Using the coherent-state formalism of the path integral, we derive a generalized master equation for the single-mode optical field. Our analysis explicitly shows how non-Markovian effects manifest in the exact decoherence dynamics for different environmental correlation time scales. Remarkably, when these are equal to or greater than the time scale for significant change in the system, the interplay between the backaction-induced coherent oscillation and the dissipative effect of the environment causes the non-Markovian effect to have a significant impact not only on the short-time behavior but also on the long-time steady-state behavior of the system.

Markovian Building Blocks for Individual-Based Modelling

DEFF Research Database (Denmark)

Nilsson, Lars Anders Fredrik

2007-01-01

previous exposure to Markov chains in continuous time (see e.g. Grimmett and Stirzaker, 2001)). Markovian arrival processes are very general point processes that are relatively easy to analyse. They have, so far, been largely unknown to the ecological modelling community. The article C deals...

Control and filtering for semi-Markovian jump systems

CERN Document Server

Li, Fanbiao; Wu, Ligang

2017-01-01

This book presents up-to-date research developments and novel methodologies on semi-Markovian jump systems (S-MJS). It presents solutions to a series of problems with new approaches for the control and filtering of S-MJS, including stability analysis, sliding mode control, dynamic output feedback control, robust filter design, and fault detection. A set of newly developed techniques such as piecewise analysis method, positively invariant set approach, event-triggered method, and cone complementary linearization approaches are presented. Control and Filtering for Semi-Markovian Jump Systems is a comprehensive reference for researcher and practitioners working in control engineering, system sciences and applied mathematics, and is also a useful source of information for senior undergraduates and graduates in these areas. The readers will benefit from some new concepts, new models and new methodologies with practical significance in control engineering and signal processing.

Non-Markovian dynamics of quantum systems: decay rate, capture and pure states

International Nuclear Information System (INIS)

Kanokov, Z.; Palchikov, Yu.V.; Antonenko, N.V.; Adamian, G.G.; Kanokov, Z.; Adamian, G.G.; Scheid, W.

2004-01-01

Full text: With the exact numerical solution of the equation for the reduced density matrix we found a minor role of the time dependence of the friction and diffusion coefficients in the escape rate from a potential well [1]. Since the used friction and diffusion coefficients were self- consistently under certain approximations derived, they preserve the positivity of the density matrix at any time. The mixed diffusion coefficient leads to a decrease of the escape rate. Since the used value of quantum diffusion coefficient in momentum is larger than the one following from a 'classic' treatment, the obtained escape rate is close to the rate calculated with the 'classic' set of diffusion coefficients. If the regime of motion is close to the under damped case or the temperature is small, the quasi-stationary escape rate can increase with friction. This is explained by the larger role of the increasing diffusion in the decay process. The agreement of the escape rate obtained with the analytical expressions in comparison to numerically calculated data depends on the characteristics of the considered system. The agreement is better in the overdamped regime. However, for any regime the deviations are not larger than in the case of the classical Kramers formula. Therefore, the analytical expressions can be applied in a large range of parameters for the potential and diffusion coefficients. We demonstrated that the uncertainty function is related to the linear entropy. The diffusion coefficients supplying the purity of states were elaborated for the non-Markovian dynamics. The obtained dependences of the capture probability on the friction proves that the quantum nature of this process should be taken into consideration when one calculates the capture cross section in nucleus-nucleus collisions

Application of Markovian model to school enrolment projection ...

African Journals Online (AJOL)

Application of Markovian model to school enrolment projection process. VU Ekhosuehi, AA Osagiede. Abstract. No Abstract. Global Journal of Mathematical Sciences Vol. 5(1) 2006: 9-16. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

Cutaneous Manifestations of Non-Celiac Gluten Sensitivity: Clinical Histological and Immunopathological Features

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Veronica Bonciolini

2015-09-01

Full Text Available Background: The dermatological manifestations associated with intestinal diseases are becoming more frequent, especially now when new clinical entities, such as Non-Celiac Gluten Sensitivity (NCGS, are identified. The existence of this new entity is still debated. However, many patients with diagnosed NCGS that present intestinal manifestations have skin lesions that need appropriate characterization. Methods: We involved 17 patients affected by NCGS with non-specific cutaneous manifestations who got much better after a gluten free diet. For a histopathological and immunopathological evaluation, two skin samples from each patient and their clinical data were collected. Results: The median age of the 17 enrolled patients affected by NCGS was 36 years and 76% of them were females. On the extensor surfaces of upper and lower limbs in particular, they all presented very itchy dermatological manifestations morphologically similar to eczema, psoriasis or dermatitis herpetiformis. This similarity was also confirmed histologically, but the immunopathological analysis showed the prevalence of deposits of C3 along the dermo-epidermal junction with a microgranular/granular pattern (82%. Conclusions: The exact characterization of new clinical entities such as Cutaneous Gluten Sensitivity and NCGS is an important objective both for diagnostic and therapeutic purposes, since these are patients who actually benefit from a GFD (Gluten Free Diet and who do not adopt it only for fashion.

Theory of and effects from elastoplasticity in nucleus-nucleus collisions

International Nuclear Information System (INIS)

Noerenberg, W.; Technische Hochschule Darmstadt

1985-02-01

Elastoplasticity of finite Fermi systems results from a coherent coupling between collective and intrinsic degrees of freedom and subsequent equilibration essentially due to two-body collisions. Within a non-markovian transport-theoretical approach referred to as dissipative diabatic dynamics (DDD), elastoplastical forms the link between giant vibrations and overdamped motion of nuclear. Obersvable effects resulting from this non-markovian behaviour in nucleus-nucleus collisions are discussed. (orig.)

Continuous Markovian Logics

DEFF Research Database (Denmark)

Mardare, Radu Iulian; Cardelli, Luca; Larsen, Kim Guldstrand

2012-01-01

Continuous Markovian Logic (CML) is a multimodal logic that expresses quantitative and qualitative properties of continuous-time labelled Markov processes with arbitrary (analytic) state-spaces, henceforth called continuous Markov processes (CMPs). The modalities of CML evaluate the rates...... of the exponentially distributed random variables that characterize the duration of the labeled transitions of a CMP. In this paper we present weak and strong complete axiomatizations for CML and prove a series of metaproperties, including the finite model property and the construction of canonical models. CML...... characterizes stochastic bisimilarity and it supports the definition of a quantified extension of the satisfiability relation that measures the "compatibility" between a model and a property. In this context, the metaproperties allows us to prove two robustness theorems for the logic stating that one can...

TIPPtool: Compositional Specification and Analysis of Markovian Performance Models

NARCIS (Netherlands)

Hermanns, H.; Halbwachs, N.; Peled, D.; Mertsiotakis, V.; Siegle, M.

1999-01-01

In this short paper we briefly describe a tool which is based on a Markovian stochastic process algebra. The tool offers both model specification and quantitative model analysis in a compositional fashion, wrapped in a userfriendly graphical front-end.

Imaging of supradiaphragmatic manifestations of extranodal nonHodgkin's lymphoma

International Nuclear Information System (INIS)

Cohnen, M.; Saleh, A.; Engelbrecht, V.; Moedder, U.; Germing, U.

2002-01-01

Malignant lymphomas are differentiated into Hodgkin's and non-Hodgkin's-lymphoma (NHL). The following article discusses the imaging of extranodal NHL in supradiaphragmatic localizations. Lymphoma can affect nearly all tissues, and represent a rare entity as primary extranodal NHL. A secondary involvement of non-nodal tissue as consequence of a generalized lymphoproliferative disease is more common,and may be seen as well in HIV-positive patients defining AIDS. As extranodal lymphoma mimick the radiologic appearance of other malignant tumors, direct diagnosis without histologic analysis is often impossible. The article describes typical manifestations of lymphoma of the lungs, the head and neck area including the large glands, and rare localizations as the heart or the breast. (orig.) [de

a markovian study of manpow an study of manpower planning

African Journals Online (AJOL)

eobe

The Markovian method of manpower planning foretell the future. ... ive years from a soft drink manufacturing company based in Lagos, Nigeria company based ... ces management approach. ... handbook have also used Markov processes for.

Multilevel Approximations of Markovian Jump Processes with Applications in Communication Networks

KAUST Repository

Vilanova, Pedro

2015-05-04

This thesis focuses on the development and analysis of efficient simulation and inference techniques for Markovian pure jump processes with a view towards applications in dense communication networks. These techniques are especially relevant for modeling networks of smart devices —tiny, abundant microprocessors with integrated sensors and wireless communication abilities— that form highly complex and diverse communication networks. During 2010, the number of devices connected to the Internet exceeded the number of people on Earth: over 12.5 billion devices. By 2015, Cisco’s Internet Business Solutions Group predicts that this number will exceed 25 billion. The first part of this work proposes novel numerical methods to estimate, in an efficient and accurate way, observables from realizations of Markovian jump processes. In particular, hybrid Monte Carlo type methods are developed that combine the exact and approximate simulation algorithms to exploit their respective advantages. These methods are tailored to keep a global computational error below a prescribed global error tolerance and within a given statistical confidence level. Indeed, the computational work of these methods is similar to the one of an exact method, but with a smaller constant. Finally, the methods are extended to systems with a disparity of time scales. The second part develops novel inference methods to estimate the parameters of Markovian pure jump process. First, an indirect inference approach is presented, which is based on upscaled representations and does not require sampling. This method is simpler than dealing directly with the likelihood of the process, which, in general, cannot be expressed in closed form and whose maximization requires computationally intensive sampling techniques. Second, a forward-reverse Monte Carlo Expectation-Maximization algorithm is provided to approximate a local maximum or saddle point of the likelihood function of the parameters given a set of

Stability and Linear Quadratic Differential Games of Discrete-Time Markovian Jump Linear Systems with State-Dependent Noise

Directory of Open Access Journals (Sweden)

Huiying Sun

2014-01-01

Full Text Available We mainly consider the stability of discrete-time Markovian jump linear systems with state-dependent noise as well as its linear quadratic (LQ differential games. A necessary and sufficient condition involved with the connection between stochastic Tn-stability of Markovian jump linear systems with state-dependent noise and Lyapunov equation is proposed. And using the theory of stochastic Tn-stability, we give the optimal strategies and the optimal cost values for infinite horizon LQ stochastic differential games. It is demonstrated that the solutions of infinite horizon LQ stochastic differential games are concerned with four coupled generalized algebraic Riccati equations (GAREs. Finally, an iterative algorithm is presented to solve the four coupled GAREs and a simulation example is given to illustrate the effectiveness of it.

Bayesian feedback versus Markovian feedback in a two-level atom

International Nuclear Information System (INIS)

Wiseman, H.M.; Mancini, Stefano; Wang Jin

2002-01-01

We compare two different approaches to the control of the dynamics of a continuously monitored open quantum system. The first is Markovian feedback, as introduced in quantum optics by Wiseman and Milburn [Phys. Rev. Lett. 70, 548 (1993)]. The second is feedback based on an estimate of the system state, developed recently by Doherty and Jacobs [Phys. Rev. A 60, 2700 (1999)]. Here we choose to call it, for brevity, Bayesian feedback. For systems with nonlinear dynamics, we expect these two methods of feedback control to give markedly different results. The simplest possible nonlinear system is a driven and damped two-level atom, so we choose this as our model system. The monitoring is taken to be homodyne detection of the atomic fluorescence, and the control is by modulating the driving. The aim of the feedback in both cases is to stabilize the internal state of the atom as close as possible to an arbitrarily chosen pure state, in the presence of inefficient detection and other forms of decoherence. Our results (obtained without recourse to stochastic simulations) prove that Bayesian feedback is never inferior, and is usually superior, to Markovian feedback. However, it would be far more difficult to implement than Markovian feedback and it loses its superiority when obvious simplifying approximations are made. It is thus not clear which form of feedback would be better in the face of inevitable experimental imperfections

Markovian Processes for Quantitative Information Leakage

DEFF Research Database (Denmark)

Biondi, Fabrizio

Quantification of information leakage is a successful approach for evaluating the security of a system. It models the system to be analyzed as a channel with the secret as the input and an output as observable by the attacker as the output, and applies information theory to quantify the amount...... and randomized processes with Markovian models and to compute their information leakage for a very general model of attacker. We present the QUAIL tool that automates such analysis and is able to compute the information leakage of an imperative WHILE language. Finally, we show how to use QUAIL to analyze some...... of information transmitted through such channel, thus effectively quantifying how many bits of the secret can be inferred by the attacker by analyzing the system’s output. Channels are usually encoded as matrices of conditional probabilities, known as channel matrices. Such matrices grow exponentially...

Deviation from the kinetic law of mass action for reactions induced by binary encounters in liquid solutions

International Nuclear Information System (INIS)

Doktorov, Alexander B; Kipriyanov, Alexey A

2007-01-01

In considering the irreversible chemical reaction A+B→ C+B in liquid solutions two many-particle approaches to the derivation of binary non-Markovian kinetic equations are compared: simple superposition decoupling and a method of extracting 'pair' channels from three-particle correlation evolution. It is shown that both methods provide an almost identical description of this reaction. However, in studies of reversible reactions in liquid solutions only the channel extraction method gives a correct physically clear description of the reaction though it consists of a sequence of steps: the development of integral encounter theory (IET), effective pairs approximation (EPA), modified encounter theory (MET), and the final regular form (RF) of kinetic equations. It is shown that the rate equations often encountered in the literature correspond to the independence of transient channels of 'scattering' in the bimolecular reversible reaction (A+B -B), while the independent transient channel of 'decay' in the reversible reactionA+B -C is defined solely by time integral convolution. In the general case transient channels in non-Markovian theory are not independent, and their interference manifests itself as a non-Markovian inhomogeneous source in binary non-Markovian kinetic equations in regular form. Based on the derived equations new universal kinetics (independent of models) of chemical equilibrium attainment have been obtained. It is shown that these kinetics can differ essentially from the kinetics corresponding to the kinetic law of mass action of formal chemical kinetics

Solving QCD evolution equations in rapidity space with Markovian Monte Carlo

CERN Document Server

Golec-Biernat, K; Placzek, W; Skrzypek, M

2009-01-01

This work covers methodology of solving QCD evolution equation of the parton distribution using Markovian Monte Carlo (MMC) algorithms in a class of models ranging from DGLAP to CCFM. One of the purposes of the above MMCs is to test the other more sophisticated Monte Carlo programs, the so-called Constrained Monte Carlo (CMC) programs, which will be used as a building block in the parton shower MC. This is why the mapping of the evolution variables (eikonal variable and evolution time) into four-momenta is also defined and tested. The evolution time is identified with the rapidity variable of the emitted parton. The presented MMCs are tested independently, with ~0.1% precision, against the non-MC program APCheb especially devised for this purpose.

Sojourn time distributions in a Markovian G-queue with batch arrival and batch removal

Directory of Open Access Journals (Sweden)

Yang Woo Shin

1999-01-01

Full Text Available We consider a single server Markovian queue with two types of customers; positive and negative, where positive customers arrive in batches and arrivals of negative customers remove positive customers in batches. Only positive customers form a queue and negative customers just reduce the system congestion by removing positive ones upon their arrivals. We derive the LSTs of sojourn time distributions for a single server Markovian queue with positive customers and negative customers by using the first passage time arguments for Markov chains.

Exponential Synchronization for Stochastic Neural Networks with Mixed Time Delays and Markovian Jump Parameters via Sampled Data

Directory of Open Access Journals (Sweden)

Yingwei Li

2014-01-01

Full Text Available The exponential synchronization issue for stochastic neural networks (SNNs with mixed time delays and Markovian jump parameters using sampled-data controller is investigated. Based on a novel Lyapunov-Krasovskii functional, stochastic analysis theory, and linear matrix inequality (LMI approach, we derived some novel sufficient conditions that guarantee that the master systems exponentially synchronize with the slave systems. The design method of the desired sampled-data controller is also proposed. To reflect the most dynamical behaviors of the system, both Markovian jump parameters and stochastic disturbance are considered, where stochastic disturbances are given in the form of a Brownian motion. The results obtained in this paper are a little conservative comparing the previous results in the literature. Finally, two numerical examples are given to illustrate the effectiveness of the proposed methods.

Manifestly non-Gaussian fluctuations in superconductor-normal metal tunnel nanostructures

Energy Technology Data Exchange (ETDEWEB)

Laakso, Matti [Institut fuer Theorie der Statistischen Physik, RWTH Aachen University, Aachen (Germany); Low Temperature Laboratory, Aalto University, Espoo (Finland); Heikkilae, Tero [Low Temperature Laboratory, Aalto University, Espoo (Finland); Nazarov, Yuli [Kavli Institute of Nanoscience, Delft University of Technology, Delft (Netherlands)

2013-07-01

Recently, temperature fluctuation statistics has been studied in non-interacting islands and overheated single-electron transistors. We propose a mesoscopic setup which exhibits strong and manifestly non-Gaussian fluctuations of energy and temperature when suitably driven out of equilibrium. The setup consists of a normal metal island (N) coupled by tunnel junctions (I) to two superconducting leads (S), forming a SINIS structure, and is biased near the threshold voltage for quasiparticle tunneling, eV ∼ 2Δ. The fluctuations can be measured by monitoring the time-dependent electric current through the system, which makes the setup suitable for the realization of feedback schemes which allow to stabilize the temperature to the desired value.

Markovian Dynamics of Josephson Parametric Amplification

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W. Kaiser

2017-09-01

Full Text Available In this work, we derive the dynamics of the lossy DC pumped non-degenerate Josephson parametric amplifier (DCPJPA. The main element in a DCPJPA is the superconducting Josephson junction. The DC bias generates the AC Josephson current varying the nonlinear inductance of the junction. By this way the Josephson junction acts as the pump oscillator as well as the time varying reactance of the parametric amplifier. In quantum-limited amplification, losses and noise have an increased impact on the characteristics of an amplifier. We outline the classical model of the lossy DCPJPA and derive the available noise power spectral densities. A classical treatment is not capable of including properties like spontaneous emission which is mandatory in case of amplification at the quantum limit. Thus, we derive a quantum mechanical model of the lossy DCPJPA. Thermal losses are modeled by the quantum Langevin approach, by coupling the quantized system to a photon heat bath in thermodynamic equilibrium. The mode occupation in the bath follows the Bose-Einstein statistics. Based on the second quantization formalism, we derive the Heisenberg equations of motion of both resonator modes. We assume the dynamics of the system to follow the Markovian approximation, i.e. the system only depends on its actual state and is memory-free. We explicitly compute the time evolution of the contributions to the signal mode energy and give numeric examples based on different damping and coupling constants. Our analytic results show, that this model is capable of including thermal noise into the description of the DC pumped non-degenerate Josephson parametric amplifier.

Markovian Dynamics of Josephson Parametric Amplification

Science.gov (United States)

Kaiser, Waldemar; Haider, Michael; Russer, Johannes A.; Russer, Peter; Jirauschek, Christian

2017-09-01

In this work, we derive the dynamics of the lossy DC pumped non-degenerate Josephson parametric amplifier (DCPJPA). The main element in a DCPJPA is the superconducting Josephson junction. The DC bias generates the AC Josephson current varying the nonlinear inductance of the junction. By this way the Josephson junction acts as the pump oscillator as well as the time varying reactance of the parametric amplifier. In quantum-limited amplification, losses and noise have an increased impact on the characteristics of an amplifier. We outline the classical model of the lossy DCPJPA and derive the available noise power spectral densities. A classical treatment is not capable of including properties like spontaneous emission which is mandatory in case of amplification at the quantum limit. Thus, we derive a quantum mechanical model of the lossy DCPJPA. Thermal losses are modeled by the quantum Langevin approach, by coupling the quantized system to a photon heat bath in thermodynamic equilibrium. The mode occupation in the bath follows the Bose-Einstein statistics. Based on the second quantization formalism, we derive the Heisenberg equations of motion of both resonator modes. We assume the dynamics of the system to follow the Markovian approximation, i.e. the system only depends on its actual state and is memory-free. We explicitly compute the time evolution of the contributions to the signal mode energy and give numeric examples based on different damping and coupling constants. Our analytic results show, that this model is capable of including thermal noise into the description of the DC pumped non-degenerate Josephson parametric amplifier.

Robust stability analysis for Markovian jumping interval neural networks with discrete and distributed time-varying delays

International Nuclear Information System (INIS)

Balasubramaniam, P.; Lakshmanan, S.; Manivannan, A.

2012-01-01

Highlights: ► Robust stability analysis for Markovian jumping interval neural networks is considered. ► Both linear fractional and interval uncertainties are considered. ► A new LKF is constructed with triple integral terms. ► MATLAB LMI control toolbox is used to validate theoretical results. ► Numerical examples are given to illustrate the effectiveness of the proposed method. - Abstract: This paper investigates robust stability analysis for Markovian jumping interval neural networks with discrete and distributed time-varying delays. The parameter uncertainties are assumed to be bounded in given compact sets. The delay is assumed to be time-varying and belong to a given interval, which means that the lower and upper bounds of interval time-varying delays are available. Based on the new Lyapunov–Krasovskii functional (LKF), some inequality techniques and stochastic stability theory, new delay-dependent stability criteria have been obtained in terms of linear matrix inequalities (LMIs). Finally, two numerical examples are given to illustrate the less conservative and effectiveness of our theoretical results.

Mixed H2/H∞ Pitch Control of Wind Turbine with a Markovian Jump Model

DEFF Research Database (Denmark)

Lin, Zhongwei; Liu, Jizhen; Wu, Qiuwei

2016-01-01

This paper proposes a Markovian jump model and the corresponding H2 /H∞ control strategy for the wind turbine driven by the stochastic switching wind speed, which can be used to regulate the generator speed in order to harvest the rated power while reducing the fatigue loads on the mechanical side...... operating points of wind turbine can be divided into separate subregions correspondingly, where the model parameters and the control mode can be fixed in each mode. Then, the mixed H2 /H∞ control problem is discussed for such a class of Markovian jump wind turbine working above the rated wind speed...

A hybrid stochastic hierarchy equations of motion approach to treat the low temperature dynamics of non-Markovian open quantum systems

Science.gov (United States)

Moix, Jeremy M.; Cao, Jianshu

2013-10-01

The hierarchical equations of motion technique has found widespread success as a tool to generate the numerically exact dynamics of non-Markovian open quantum systems. However, its application to low temperature environments remains a serious challenge due to the need for a deep hierarchy that arises from the Matsubara expansion of the bath correlation function. Here we present a hybrid stochastic hierarchical equation of motion (sHEOM) approach that alleviates this bottleneck and leads to a numerical cost that is nearly independent of temperature. Additionally, the sHEOM method generally converges with fewer hierarchy tiers allowing for the treatment of larger systems. Benchmark calculations are presented on the dynamics of two level systems at both high and low temperatures to demonstrate the efficacy of the approach. Then the hybrid method is used to generate the exact dynamics of systems that are nearly impossible to treat by the standard hierarchy. First, exact energy transfer rates are calculated across a broad range of temperatures revealing the deviations from the Förster rates. This is followed by computations of the entanglement dynamics in a system of two qubits at low temperature spanning the weak to strong system-bath coupling regimes.

Adaptive Asymptotical Synchronization for Stochastic Complex Networks with Time-Delay and Markovian Switching

Directory of Open Access Journals (Sweden)

Xueling Jiang

2014-01-01

Full Text Available The problem of adaptive asymptotical synchronization is discussed for the stochastic complex dynamical networks with time-delay and Markovian switching. By applying the stochastic analysis approach and the M-matrix method for stochastic complex networks, several sufficient conditions to ensure adaptive asymptotical synchronization for stochastic complex networks are derived. Through the adaptive feedback control techniques, some suitable parameters update laws are obtained. Simulation result is provided to substantiate the effectiveness and characteristics of the proposed approach.

Nodal infection in Markovian susceptible-infected-susceptible and susceptible-infected-removed epidemics on networks are non-negatively correlated.

Science.gov (United States)

Cator, E; Van Mieghem, P

2014-05-01

By invoking the famous Fortuin, Kasteleyn, and Ginibre (FKG) inequality, we prove the conjecture that the correlation of infection at the same time between any pair of nodes in a network cannot be negative for (exact) Markovian susceptible-infected-susceptible (SIS) and susceptible-infected-removed (SIR) epidemics on networks. The truth of the conjecture establishes that the N-intertwined mean-field approximation (NIMFA) upper bounds the infection probability in any graph so that network design based on NIMFA always leads to safe protections against malware spread. However, when the infection or/and curing are not Poisson processes, the infection correlation between two nodes can be negative.

Nodal infection in Markovian susceptible-infected-susceptible and susceptible-infected-removed epidemics on networks are non-negatively correlated

Science.gov (United States)

Cator, E.; Van Mieghem, P.

2014-05-01

By invoking the famous Fortuin, Kasteleyn, and Ginibre (FKG) inequality, we prove the conjecture that the correlation of infection at the same time between any pair of nodes in a network cannot be negative for (exact) Markovian susceptible-infected-susceptible (SIS) and susceptible-infected-removed (SIR) epidemics on networks. The truth of the conjecture establishes that the N-intertwined mean-field approximation (NIMFA) upper bounds the infection probability in any graph so that network design based on NIMFA always leads to safe protections against malware spread. However, when the infection or/and curing are not Poisson processes, the infection correlation between two nodes can be negative.

19 CFR 122.75b - Electronic manifest requirement for crew members and non-crew members onboard commercial aircraft...

Science.gov (United States)

2010-04-01

... 19 Customs Duties 1 2010-04-01 2010-04-01 false Electronic manifest requirement for crew members... THE TREASURY AIR COMMERCE REGULATIONS Documents Required for Clearance and Permission To Depart; Electronic Manifest Requirements for Passengers, Crew Members, and Non-Crew Members Onboard Commercial...

Markovian agents models for wireless sensor networks deployed in environmental protection

International Nuclear Information System (INIS)

Cerotti, Davide; Gribaudo, Marco; Bobbio, Andrea

2014-01-01

Wireless sensor networks (WSNs) are gaining popularity as distributed monitoring systems in safety critical applications, when the location to be controlled may be dangerous for a human operator or difficult to access. Fire is one of the major thread in urban as well as in open environments, and WSNs are receiving increasing attention as a mean to build effective and timely fire protection systems. The present paper presents a novel analytical technique for the study of the propagation of a fire in a wide open area and the interaction with a WSN deployed to monitor the outbreak of the fire and to send a warning signal to a base station. For the complex scenario under study, an analytical modeling and analysis technique based on Markovian agents (MAs) is discussed. It is shown that, even if the overall state space of the models is huge, nevertheless an analytical solution is feasible, by exploiting the locality of the interactions among MAs, based on a message passing mechanism combined with a perception function. - Highlights: • We present a revised theory of Markovian agent models, detailing the analysis techniques and its complexity • We a target a complex application of a wireless sensor network (WSN) that monitors forest fire. • The model captures the propagation of fire, heat, and the detection by the WSN. • We compute key performance indices such us the fire propagation front, and message travel time. • We perform an extensive set of experiments to study the effectiveness of the WSN in detecting forest fire

A note on Markovian manpower models | Osagiede | Journal of the ...

African Journals Online (AJOL)

In modelling manpower systems, most authors rely on Markov-based theoretic methodology as an analytic tool to unify the states of the system with the axiomatic foundation that there is a one-stage dependence of events. In this study, Markovian manpower models are surveyed. Specific areas are highlighted as future ...

Transport benchmarks for one-dimensional binary Markovian mixtures revisited

International Nuclear Information System (INIS)

Malvagi, F.

2013-01-01

The classic benchmarks for transport through a binary Markovian mixture are revisited to look at the probability distribution function of the chosen 'results': reflection, transmission and scalar flux. We argue that the knowledge of the ensemble averaged results is not sufficient for reliable predictions: a measure of the dispersion must also be obtained. An algorithm to estimate this dispersion is tested. (author)

Markovian Limit of a Spatio-Temporal Correlated Open Systems

Science.gov (United States)

Monnai, T.

Large fluctuation of Brownian particles is affected by the finiteness of the correlation length of the background noise field. Indeed a Fokker—Planck equation is derived in a Markovian limit of a spatio-temporal short correlated noise. Corresponding kinetic quantities are renormalized due to the spatio-temporal memory. We also investigate the case of open system by connecting a thermostat to the system.

Intact working memory in non-manifesting LRRK2 carriers--an fMRI study

NARCIS (Netherlands)

Thaler, A.; Helmich, R.C.G.; Or-Borichev, A.; Nuenen, B.F. van; Shapira-Lichter, I.; Gurevich, T.; Orr-Urtreger, A.; Marder, K.; Bressman, S.; Bloem, B.R.; Giladi, N.; Hendler, T.; Mirelman, A.

2016-01-01

Cognitive impairments are prevalent in patients with Parkinson's disease. Mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause of genetic Parkinsonism. Non-manifesting carriers of the G2019S mutation in the LRRK2 gene were found to have lower executive functions as

A cognitive fMRI study in non-manifesting LRRK2 and GBA carriers

NARCIS (Netherlands)

Bregman, N.; Thaler, A.; Mirelman, A.; Helmich, R.C.G.; Gurevich, T.; Orr-Urtreger, A.; Marder, K.; Bressman, S.; Bloem, B.R.; Giladi, N.

2017-01-01

Mutations in the GBA and LRRK2 genes account for one-third of the prevalence of Parkinson's disease (PD) in Ashkenazi Jews. Non-manifesting carriers (NMC) of these mutations represent a population at risk for future development of PD. PD patient who carry mutations in the GBA gene demonstrates more

Perturbative approach to Markovian open quantum systems.

Science.gov (United States)

Li, Andy C Y; Petruccione, F; Koch, Jens

2014-05-08

The exact treatment of Markovian open quantum systems, when based on numerical diagonalization of the Liouville super-operator or averaging over quantum trajectories, is severely limited by Hilbert space size. Perturbation theory, standard in the investigation of closed quantum systems, has remained much less developed for open quantum systems where a direct application to the Lindblad master equation is desirable. We present such a perturbative treatment which will be useful for an analytical understanding of open quantum systems and for numerical calculation of system observables which would otherwise be impractical.

Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations (I): catastrophic APS, APS nephropathy and heart valve lesions.

Science.gov (United States)

Cervera, R; Tektonidou, M G; Espinosa, G; Cabral, A R; González, E B; Erkan, D; Vadya, S; Adrogué, H E; Solomon, M; Zandman-Goddard, G; Shoenfeld, Y

2011-02-01

The objectives of the 'Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations' were to assess the clinical utility of the international consensus statement on classification criteria and treatment guidelines for the catastrophic APS, to identify and grade the studies that analyse the relationship between the antiphospholipid antibodies and the non-criteria APS manifestations and to present the current evidence regarding the accuracy of these non-criteria APS manifestations for the detection of patients with APS. This article summarizes the studies analysed on the catastrophic APS, APS nephropathy and heart valve lesions, and presents the recommendations elaborated by the Task Force after this analysis.

Dynamics of Quantum Entanglement in Reservoir with Memory Effects

International Nuclear Information System (INIS)

Hao Xiang; Sha Jinqiao; Sun Jian; Zhu Shiqun

2012-01-01

The non-Markovian dynamics of quantum entanglement is studied by the Shabani-Lidar master equation when one of entangled quantum systems is coupled to a local reservoir with memory effects. The completely positive reduced dynamical map can be constructed in the Kraus representation. Quantum entanglement decays more slowly in the non-Markovian environment. The decoherence time for quantum entanglement can be markedly increased with the change of the memory kernel. It is found out that the entanglement sudden death between quantum systems and entanglement sudden birth between the system and reservoir occur at different instants. (general)

H2 Control for the Continuous-Time Markovian Jump Linear Uncertain Systems with Partly Known Transition Rates and Input Quantization

Directory of Open Access Journals (Sweden)

Xin-Gang Zhao

2013-01-01

Full Text Available For a class of continuous-time Markovian jump linear uncertain systems with partly known transition rates and input quantization, the H2 state-feedback control design is considered. The elements in the transition rates matrix include completely known, boundary known, and completely unknown ones. First, an H2 cost index for Markovian jump linear uncertain systems is introduced; then by introducing a new matrix inequality condition, sufficient conditions are formulated in terms of linear matrix inequalities (LMIs for the H2 control of the Markovian jump linear uncertain systems. Less conservativeness is achieved than the result obtained with the existing technique. Finally, a numerical example is given to verify the validity of the theoretical results.

Impulsive synchronization of Markovian jumping randomly coupled neural networks with partly unknown transition probabilities via multiple integral approach.

Science.gov (United States)

Chandrasekar, A; Rakkiyappan, R; Cao, Jinde

2015-10-01

This paper studies the impulsive synchronization of Markovian jumping randomly coupled neural networks with partly unknown transition probabilities via multiple integral approach. The array of neural networks are coupled in a random fashion which is governed by Bernoulli random variable. The aim of this paper is to obtain the synchronization criteria, which is suitable for both exactly known and partly unknown transition probabilities such that the coupled neural network is synchronized with mixed time-delay. The considered impulsive effects can be synchronized at partly unknown transition probabilities. Besides, a multiple integral approach is also proposed to strengthen the Markovian jumping randomly coupled neural networks with partly unknown transition probabilities. By making use of Kronecker product and some useful integral inequalities, a novel Lyapunov-Krasovskii functional was designed for handling the coupled neural network with mixed delay and then impulsive synchronization criteria are solvable in a set of linear matrix inequalities. Finally, numerical examples are presented to illustrate the effectiveness and advantages of the theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

Non-markovian boltzmann equation

International Nuclear Information System (INIS)

Kremp, D.; Bonitz, M.; Kraeft, W.D.; Schlanges, M.

1997-01-01

A quantum kinetic equation for strongly interacting particles (generalized binary collision approximation, ladder or T-matrix approximation) is derived in the framework of the density operator technique. In contrast to conventional kinetic theory, which is valid on large time scales as compared to the collision (correlation) time only, our approach retains the full time dependencies, especially also on short time scales. This means retardation and memory effects resulting from the dynamics of binary correlations and initial correlations are included. Furthermore, the resulting kinetic equation conserves total energy (the sum of kinetic and potential energy). The second aspect of generalization is the inclusion of many-body effects, such as self-energy, i.e., renormalization of single-particle energies and damping. To this end we introduce an improved closure relation to the Bogolyubov endash Born endash Green endash Kirkwood endash Yvon hierarchy. Furthermore, in order to express the collision integrals in terms of familiar scattering quantities (Mo/ller operator, T-matrix), we generalize the methods of quantum scattering theory by the inclusion of medium effects. To illustrate the effects of memory and damping, the results of numerical simulations are presented. copyright 1997 Academic Press, Inc

A Markovian Entropy Measure for the Analysis of Calcium Activity Time Series.

Science.gov (United States)

Marken, John P; Halleran, Andrew D; Rahman, Atiqur; Odorizzi, Laura; LeFew, Michael C; Golino, Caroline A; Kemper, Peter; Saha, Margaret S

2016-01-01

Methods to analyze the dynamics of calcium activity often rely on visually distinguishable features in time series data such as spikes, waves, or oscillations. However, systems such as the developing nervous system display a complex, irregular type of calcium activity which makes the use of such methods less appropriate. Instead, for such systems there exists a class of methods (including information theoretic, power spectral, and fractal analysis approaches) which use more fundamental properties of the time series to analyze the observed calcium dynamics. We present a new analysis method in this class, the Markovian Entropy measure, which is an easily implementable calcium time series analysis method which represents the observed calcium activity as a realization of a Markov Process and describes its dynamics in terms of the level of predictability underlying the transitions between the states of the process. We applied our and other commonly used calcium analysis methods on a dataset from Xenopus laevis neural progenitors which displays irregular calcium activity and a dataset from murine synaptic neurons which displays activity time series that are well-described by visually-distinguishable features. We find that the Markovian Entropy measure is able to distinguish between biologically distinct populations in both datasets, and that it can separate biologically distinct populations to a greater extent than other methods in the dataset exhibiting irregular calcium activity. These results support the benefit of using the Markovian Entropy measure to analyze calcium dynamics, particularly for studies using time series data which do not exhibit easily distinguishable features.

A Markovian Entropy Measure for the Analysis of Calcium Activity Time Series.

Directory of Open Access Journals (Sweden)

John P Marken

Full Text Available Methods to analyze the dynamics of calcium activity often rely on visually distinguishable features in time series data such as spikes, waves, or oscillations. However, systems such as the developing nervous system display a complex, irregular type of calcium activity which makes the use of such methods less appropriate. Instead, for such systems there exists a class of methods (including information theoretic, power spectral, and fractal analysis approaches which use more fundamental properties of the time series to analyze the observed calcium dynamics. We present a new analysis method in this class, the Markovian Entropy measure, which is an easily implementable calcium time series analysis method which represents the observed calcium activity as a realization of a Markov Process and describes its dynamics in terms of the level of predictability underlying the transitions between the states of the process. We applied our and other commonly used calcium analysis methods on a dataset from Xenopus laevis neural progenitors which displays irregular calcium activity and a dataset from murine synaptic neurons which displays activity time series that are well-described by visually-distinguishable features. We find that the Markovian Entropy measure is able to distinguish between biologically distinct populations in both datasets, and that it can separate biologically distinct populations to a greater extent than other methods in the dataset exhibiting irregular calcium activity. These results support the benefit of using the Markovian Entropy measure to analyze calcium dynamics, particularly for studies using time series data which do not exhibit easily distinguishable features.

Analysis and design of singular Markovian jump systems

CERN Document Server

Wang, Guoliang; Yan, Xinggang

2014-01-01

This monograph is an up-to-date presentation of the analysis and design of singular Markovian jump systems (SMJSs) in which the transition rate matrix of the underlying systems is generally uncertain, partially unknown and designed. The problems addressed include stability, stabilization, H∞ control and filtering, observer design, and adaptive control. applications of Markov process are investigated by using Lyapunov theory, linear matrix inequalities (LMIs), S-procedure and the stochastic Barbalat's Lemma, among other techniques.Features of the book include:·???????? study of the stability pr

Memory-keeping effects and forgetfulness in the dynamics of a qubit coupled to a spin chain

International Nuclear Information System (INIS)

Apollaro, Tony J. G.; Di Franco, Carlo; Plastina, Francesco; Paternostro, Mauro

2011-01-01

Using recently proposed measures for non-Markovianity [H.-P. Breuer, E. M. Laine, and J. Piilo, Phys. Rev. Lett. 103, 210401 (2009)], we study the dynamics of a qubit coupled to a spin environment via an energy-exchange mechanism. We show the existence of a point, in the parameter space of the system, where the qubit dynamics is effectively Markovian and that such a point separates two regions with completely different dynamical behaviors. Indeed, our study demonstrates that the qubit evolution can in principle be tuned from a perfectly forgetful one to a deep non-Markovian regime where the qubit is strongly affected by the dynamical backaction of the environmental spins. By means of a theoretical quantum process tomography analysis, we provide a complete and intuitive characterization of the qubit channel.

Stability of the Markov operator and synchronization of Markovian random products

Science.gov (United States)

Díaz, Lorenzo J.; Matias, Edgar

2018-05-01

We study Markovian random products on a large class of ‘m-dimensional’ connected compact metric spaces (including products of closed intervals and trees). We introduce a splitting condition, generalizing the classical one by Dubins and Freedman, and prove that this condition implies the asymptotic stability of the corresponding Markov operator and (exponentially fast) synchronization.

Counter-rotating effects and entanglement dynamics in strongly coupled quantum-emitter-metallic-nanoparticle structures

Science.gov (United States)

Iliopoulos, Nikos; Thanopulos, Ioannis; Yannopapas, Vassilios; Paspalakis, Emmanuel

2018-03-01

We study the spontaneous emission of a two-level quantum emitter next to a plasmonic nanoparticle beyond the Markovian approximation and the rotating-wave approximation (RWA) by combining quantum dynamics and classical electromagnetic calculations. For emitters with decay times in the picosecond to nanosecond time regime, as well as located at distances from the nanoparticle up to its radius, the dynamics with and without the RWA and the transition from the non-Markovian to the Markovian regime are investigated. For emitters with longer decay times, the Markov approximation proves to be adequate for distances larger than half the nanoparticle radius. However, the RWA is correct for all distances of the emitter from the nanoparticle. For short decay time emitters, the Markov approximation and RWA are both inadequate, with only the RWA becoming valid again at a distance larger than half the nanoparticle radius. We also show that the entanglement dynamics of two initially entangled qubits interacting independently with the nanoparticle may have a strong non-Markovian character when counter-rotating effects are included. Interesting effects such as entanglement sudden death, periodic entanglement revival, entanglement oscillations, and entanglement trapping are further observed when different initial two-qubit states and different distances between the qubit and the nanoparticle are considered.

Computing Rates of Small Molecule Diffusion Through Protein Channels Using Markovian Milestoning

Science.gov (United States)

Abrams, Cameron

2014-03-01

Measuring diffusion rates of ligands plays a key role in understanding the kinetic processes inside proteins. For example, although many molecular simulation studies have reported free energy barriers to infer rates for CO diffusion in myoglobin (Mb), they typically do not include direct calculation of diffusion rates because of the long simulation times needed to infer these rates with statistical accuracy. We show in this talk how to apply Markovian milestoning along minimum free-energy pathways to calculate diffusion rates of CO inside Mb. In Markovian milestoning, one partitions a suitable reaction coordinate space into regions and performs restrained molecular dynamics in each region to accumulate kinetic statistics that, when assembled across regions, provides an estimate of the mean first-passage time between states. The mean escape time for CO directly from the so-called distal pocket (DP) through the histidine gate (HG) is estimated at about 24 ns, confirming the importance of this portal for CO. But Mb is known to contain several internal cavities, and cavity-to-cavity diffusion rates are also computed and used to build a complete kinetic network as a Markov state model. Within this framework, the effective mean time of escape to the solvent through HG increases to 30 ns. Our results suggest that carrier protein structure may have evolved under pressure to modulate dissolved gas release rates using a network of ligand-accessible cavities. Support: NIH R01GM100472.

Robust stability of uncertain Markovian jumping Cohen-Grossberg neural networks with mixed time-varying delays

International Nuclear Information System (INIS)

Sheng Li; Yang Huizhong

2009-01-01

This paper considers the robust stability of a class of uncertain Markovian jumping Cohen-Grossberg neural networks (UMJCGNNs) with mixed time-varying delays. The parameter uncertainties are norm-bounded and the mixed time-varying delays comprise discrete and distributed time delays. Based on the Lyapunov stability theory and linear matrix inequality (LMI) technique, some robust stability conditions guaranteeing the global robust convergence of the equilibrium point are derived. An example is given to show the effectiveness of the proposed results.

Weight loss and skin manifestations in obese patients with psoriasis

DEFF Research Database (Denmark)

Geiker, Nina Rica Wium; Jensen, Peter; Kirchner Larsson, Lena

Objective To examine if psoriatic patients can achieve a weight loss to the same extent as non-psoriatic patients To describe the effect of weight loss on the cutaneous manifestations. Conclusion Patients with psoriasis achieved a weight loss, similar to non-psoriatic patients, of 12...... % of their body weight following calorie restriction for 12 weeks. Taken together with recent literature the findings suggest that weight loss has a potential to reduce skin manifestations. Weight loss might also attenuate the increased cardiovascular and diabetes risks posed by obese psoriatric patients....

Beyond the CRAB symptoms: a study of presenting clinical manifestations of multiple myeloma.

Science.gov (United States)

Talamo, Giampaolo; Farooq, Umar; Zangari, Maurizio; Liao, Jason; Dolloff, Nathan G; Loughran, Thomas P; Epner, Elliot

2010-12-01

Although the typical clinical manifestations of multiple myeloma (MM) are summarized by the CRAB symptoms (hypercalcemia, renal insufficiency, anemia, and bone lesions), a significant proportion of patients with MM present with a variety of other clinical manifestations. We conducted a study evaluating the presenting symptoms that led to the diagnosis of MM. We conducted a retrospective review of 170 consecutive patients with MM seen at the Penn State Hershey Cancer Institute. Among patients with symptomatic MM, 74% presented with CRAB symptoms, 20% presented with non-CRAB manifestations, and 6% had both clinical features. Ten categories of non-CRAB manifestations were found, in order of decreasing frequency: neuropathy (because of spinal cord compression, nerve root compression, or peripheral neuropathy), extramedullary involvement, hyperviscosity syndrome, concomitant amyloidosis (eg, nephrotic syndrome or cardiopathy), hemorrhage/coagulopathy, systemic symptoms (eg, fever or weight loss), primary plasma cell leukemia, infections, cryoglobulinemia, and secondary gout. Kaplan-Meier estimates of survival in patients with non-CRAB manifestations did not show a significant difference from the survival of patients presenting with CRAB symptoms. Presenting symptoms of MM may be grouped in a total of 14 categories, 4 for the CRAB and 10 for the less common non-CRAB features. Grouped together, non-CRAB manifestations do not appear to confer a negative effect on the prognosis of patients with MM.

Synchronization of Markovian jumping stochastic complex networks with distributed time delays and probabilistic interval discrete time-varying delays

International Nuclear Information System (INIS)

Li Hongjie; Yue Dong

2010-01-01

The paper investigates the synchronization stability problem for a class of complex dynamical networks with Markovian jumping parameters and mixed time delays. The complex networks consist of m modes and the networks switch from one mode to another according to a Markovian chain with known transition probability. The mixed time delays are composed of discrete and distributed delays, the discrete time delay is assumed to be random and its probability distribution is known a priori. In terms of the probability distribution of the delays, the new type of system model with probability-distribution-dependent parameter matrices is proposed. Based on the stochastic analysis techniques and the properties of the Kronecker product, delay-dependent synchronization stability criteria in the mean square are derived in the form of linear matrix inequalities which can be readily solved by using the LMI toolbox in MATLAB, the solvability of derived conditions depends on not only the size of the delay, but also the probability of the delay-taking values in some intervals. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.

Intramuscular manifestation of non-Hodgkin lymphoma and myeloma: Prevalence, clinical signs, and computed tomography features

Energy Technology Data Exchange (ETDEWEB)

Surov, Alexey; Spielmann, Rolf-Peter; Behrmann, Curd (Dept. of Radiology, Martin Luther Univ., Halle-Wittenberg (Germany)), e-mail: alex.surow@medizin.uni-halle.de; Holzhausen, Hans-Juergen (Dept. of Hematology/Oncology, Martin Luther Univ., Halle-Wittenberg (Germany)); Arnold, Dirk (Dept. of Pathology, Martin Luther Univ., Halle-Wittenberg (Germany)); Schmidt, Joerg (Dept. of Medical Statistics and Controlling, Martin Luther Univ., Halle-Wittenberg (Germany))

2010-01-15

Background: Intramuscular manifestations of malignant immuno proliferative diseases (IMMID) are very rare. Purpose: To determine the prevalence and the clinical features of IMMID in a large series of patients, and to analyze their radiological appearances. Material and Methods: Between 1997 and 2007, 20 patients with IMMID (non-Hodgkin lymphoma [NHL], n=14, and myeloma, n=6) were identified. All patients underwent computed tomography (CT). In five cases, magnetic resonance imaging (MRI) was additionally performed. Results: Clinically, 16 patients presented with local pain and soft-tissue swelling. In four patients, IMMID was found incidentally. The most common site was the erector spinae muscle, followed by the iliopsoas and pelvic muscles. In 13 cases of IMMID, diffuse mass-forming muscle infiltration was found. Focal intramuscular masses were identified in seven cases. Conclusion: NHL mostly manifests as diffuse muscle enlargement, whereas myelomas form focal intramuscular masses. Nevertheless, CT and MR appearances are nonspecific and can be misinterpreted as muscle sarcoma or inflammatory disease. Although rare, muscle involvement should be considered in the differential diagnosis of muscle disorders in patients with non-Hodgkin lymphoma and myeloma

Metabolic and hormonal signatures in pre-manifest and manifest Huntington’s disease patients

Directory of Open Access Journals (Sweden)

Rui eWang

2014-06-01

Full Text Available Huntington's disease (HD is an inherited neurodegenerative disorder typified by involuntary body movements, and psychiatric and cognitive abnormalities. Many HD patients also exhibit metabolic changes including progressive weight loss and appetite dysfunction. Here we have investigated metabolic function in pre-manifest and manifest HD subjects to establish an HD subject metabolic hormonal plasma signature. Individuals at risk for HD who have had predictive genetic testing showing the cytosine-adenine-guanine (CAG expansion causative of HD, but who do not yet present signs and symptoms sufficient for the diagnosis of manifest HD are said to be pre-manifest. Pre-manifest and manifest HD patients, as well as both familial and non-familial controls, were evaluated for multiple peripheral metabolism signals including circulating levels of hormones, growth factors, lipids and cytokines. Both pre-manifest and manifest HD subjects exhibited significantly reduced levels of circulating growth factors, including growth hormone and prolactin. HD-related changes in the levels of metabolic hormones such as ghrelin, glucagon and amylin were also observed. Total cholesterol, HDL-C and LDL-C were significantly decreased in HD subjects. C-reactive protein was significantly elevated in pre-manifest HD subjects. The observation of metabolic alterations, even in subjects considered to be in the pre-manifest stage of HD, suggests that in addition, and prior, to overt neuronal damage, HD affects metabolic hormone secretion and energy regulation, which may shed light on pathogenesis, and provide opportunities for biomarker development.

Inhomogeneous electrochemiluminescence. II Markovian encounter theory of the phenomenon

International Nuclear Information System (INIS)

Gladkikh, V.; Burshtein, A.I.

2005-01-01

The free energy dependence of the electro-chemiluminescence quantum yield is specified, with the Markovian encounter theory accounting for the reversibility of triplet production competing with the irreversible recombination to the ground state. It is shown that diffusional ion recombination is highly inhomogeneous in space. It proceeds at either large positive ionization free energy (mainly to the triplet product) or at large negative free energy when recombination to the ground state dominates. On the contrary at medium free energies, the quasi-resonant generation of triplets is under kinetic control and therefore much more homogeneous. In this case, both recombination products are generated in comparable amounts. The multiple reversible ionization is shown to act as an independent quenching mechanism previously unknown. The role of the triplet quenching at the electrode is also specified. These effects reduce noticeably the luminescence quantum yield but only at larger triplet life times and in different free energy regions

A Markovian event-based framework for stochastic spiking neural networks.

Science.gov (United States)

Touboul, Jonathan D; Faugeras, Olivier D

2011-11-01

In spiking neural networks, the information is conveyed by the spike times, that depend on the intrinsic dynamics of each neuron, the input they receive and on the connections between neurons. In this article we study the Markovian nature of the sequence of spike times in stochastic neural networks, and in particular the ability to deduce from a spike train the next spike time, and therefore produce a description of the network activity only based on the spike times regardless of the membrane potential process. To study this question in a rigorous manner, we introduce and study an event-based description of networks of noisy integrate-and-fire neurons, i.e. that is based on the computation of the spike times. We show that the firing times of the neurons in the networks constitute a Markov chain, whose transition probability is related to the probability distribution of the interspike interval of the neurons in the network. In the cases where the Markovian model can be developed, the transition probability is explicitly derived in such classical cases of neural networks as the linear integrate-and-fire neuron models with excitatory and inhibitory interactions, for different types of synapses, possibly featuring noisy synaptic integration, transmission delays and absolute and relative refractory period. This covers most of the cases that have been investigated in the event-based description of spiking deterministic neural networks.

Quantum trajectories: Memory and continuous observation

Science.gov (United States)

Barchielli, Alberto; Pellegrini, Clément; Petruccione, Francesco

2012-12-01

Starting from a generalization of the quantum trajectory theory [based on the stochastic Schrödinger equation (SSE)], non-Markovian models of quantum dynamics are derived. In order to describe non-Markovian effects, the approach used in this article is based on the introduction of random coefficients in the usual linear SSE. A major interest is that this allows a consistent theory of quantum measurement in continuous time to be developed for these non-Markovian quantum trajectory models. In this context, the notions of “instrument,” “a priori,” and “a posteriori” states can be introduced. The key point is that by starting from a stochastic equation on the Hilbert space of the system, we are able to respect the complete positivity of the mean dynamics for the statistical operator and the requirements of the axioms of quantum measurement theory. The flexibility of the theory is next illustrated by a concrete physical model of a noisy oscillator where non-Markovian effects come from the random environment, colored noises, randomness in the stimulating light, and delay effects. The statistics of the emitted photons and the heterodyne and homodyne spectra are studied, and we show how these quantities are sensitive to the non-Markovian features of the system dynamics, so that, in principle, the observation and analysis of the fluorescent light could reveal the presence of non-Markovian effects and allow for a measure of the spectra of the noises affecting the system dynamics.

Pricing Exotic Options under a High-Order Markovian Regime Switching Model

Directory of Open Access Journals (Sweden)

Wai-Ki Ching

2007-10-01

Full Text Available We consider the pricing of exotic options when the price dynamics of the underlying risky asset are governed by a discrete-time Markovian regime-switching process driven by an observable, high-order Markov model (HOMM. We assume that the market interest rate, the drift, and the volatility of the underlying risky asset's return switch over time according to the states of the HOMM, which are interpreted as the states of an economy. We will then employ the well-known tool in actuarial science, namely, the Esscher transform to determine an equivalent martingale measure for option valuation. Moreover, we will also investigate the impact of the high-order effect of the states of the economy on the prices of some path-dependent exotic options, such as Asian options, lookback options, and barrier options.

Non - Adiabaticity and Novel Isotope Effect in the Doped Cuprates

International Nuclear Information System (INIS)

Kresin, V.; WOLF, S. A.

1995-01-01

This paper reports a novel isotope effect which is due to a strong non-adiabaticity that manifests itself in the dependence of the carrier concentration on the isotopic mass. The critical temperature in turn depends on the carrier concentration giving rise to a unique and non-phononic isotope shift. (author)

Non-diffusive transport in 3-D pressure driven plasma turbulence

International Nuclear Information System (INIS)

Del-Castillo-Negrete, D.; Carreras, B.A.; Lynch, V.

2005-01-01

Numerical evidence of non-diffusive transport in 3-dimensional, resistive, pressure-gradient-driven plasma turbulence is presented. It is shown that the probability density function (pdf) of tracers is strongly non-Gaussian and exhibits algebraic decaying tails. To describe these results, a transport model using fractional derivative operators in proposed. The model incorporates in a unified way non-locality (i.e., non-Fickian transport), memory effects (i.e., non-Markovian transport), and non-diffusive scaling features known to be present in fusion plasmas. There is quantitative agreement between the model and the turbulent transport numerical calculations. In particular, the model reproduces the shape and space-time scaling of the pdf, and the super-diffusive scaling of the moments. (author)

On the Moments and the Distribution of Aggregate Discounted Claims in a Markovian Environment

Directory of Open Access Journals (Sweden)

Shuanming Li

2018-05-01

Full Text Available This paper studies the moments and the distribution of the aggregate discounted claims (ADCs in a Markovian environment, where the claim arrivals, claim amounts, and forces of interest (for discounting are influenced by an underlying Markov process. Specifically, we assume that claims occur according to a Markovian arrival process (MAP. The paper shows that the vector of joint Laplace transforms of the ADC occurring in each state of the environment process by any specific time satisfies a matrix-form first-order partial differential equation, through which a recursive formula is derived for the moments of the ADC occurring in certain states (a subset. We also study two types of covariances of the ADC occurring in any two subsets of the state space and with two different time lengths. The distribution of the ADC occurring in certain states by any specific time is also investigated. Numerical results are also presented for a two-state Markov-modulated model case.

Decentralised output feedback control of Markovian jump interconnected systems with unknown interconnections

Science.gov (United States)

Li, Li-Wei; Yang, Guang-Hong

2017-07-01

The problem of decentralised output feedback control is addressed for Markovian jump interconnected systems with unknown interconnections and general transition rates (TRs) allowed to be unknown or known with uncertainties. A class of decentralised dynamic output feedback controllers are constructed, and a cyclic-small-gain condition is exploited to dispose the unknown interconnections so that the resultant closed-loop system is stochastically stable and satisfies an H∞ performance. With slack matrices to cope with the nonlinearities incurred by unknown and uncertain TRs in control synthesis, a novel controller design condition is developed in linear matrix inequality formalism. Compared with the existing works, the proposed approach leads to less conservatism. Finally, two examples are used to illustrate the effectiveness of the new results.

Some recent developments in non-equilibrium statistical physics

Indian Academy of Sciences (India)

: ... This canonical prescription is the starting point for studying a system in ... abilistic approach to non-equilibrium dynamics by treating the case of Markovian ..... equation in this network between the incoming flux and the outgoing flux at each.

Quantum adiabatic Markovian master equations

International Nuclear Information System (INIS)

Albash, Tameem; Zanardi, Paolo; Boixo, Sergio; Lidar, Daniel A

2012-01-01

We develop from first principles Markovian master equations suited for studying the time evolution of a system evolving adiabatically while coupled weakly to a thermal bath. We derive two sets of equations in the adiabatic limit, one using the rotating wave (secular) approximation that results in a master equation in Lindblad form, the other without the rotating wave approximation but not in Lindblad form. The two equations make markedly different predictions depending on whether or not the Lamb shift is included. Our analysis keeps track of the various time and energy scales associated with the various approximations we make, and thus allows for a systematic inclusion of higher order corrections, in particular beyond the adiabatic limit. We use our formalism to study the evolution of an Ising spin chain in a transverse field and coupled to a thermal bosonic bath, for which we identify four distinct evolution phases. While we do not expect this to be a generic feature, in one of these phases dissipation acts to increase the fidelity of the system state relative to the adiabatic ground state. (paper)

Hard decoding algorithm for optimizing thresholds under general Markovian noise

Science.gov (United States)

Chamberland, Christopher; Wallman, Joel; Beale, Stefanie; Laflamme, Raymond

2017-04-01

Quantum error correction is instrumental in protecting quantum systems from noise in quantum computing and communication settings. Pauli channels can be efficiently simulated and threshold values for Pauli error rates under a variety of error-correcting codes have been obtained. However, realistic quantum systems can undergo noise processes that differ significantly from Pauli noise. In this paper, we present an efficient hard decoding algorithm for optimizing thresholds and lowering failure rates of an error-correcting code under general completely positive and trace-preserving (i.e., Markovian) noise. We use our hard decoding algorithm to study the performance of several error-correcting codes under various non-Pauli noise models by computing threshold values and failure rates for these codes. We compare the performance of our hard decoding algorithm to decoders optimized for depolarizing noise and show improvements in thresholds and reductions in failure rates by several orders of magnitude. Our hard decoding algorithm can also be adapted to take advantage of a code's non-Pauli transversal gates to further suppress noise. For example, we show that using the transversal gates of the 5-qubit code allows arbitrary rotations around certain axes to be perfectly corrected. Furthermore, we show that Pauli twirling can increase or decrease the threshold depending upon the code properties. Lastly, we show that even if the physical noise model differs slightly from the hypothesized noise model used to determine an optimized decoder, failure rates can still be reduced by applying our hard decoding algorithm.

Non-cardiac manifestations of Marfan syndrome

Science.gov (United States)

2017-01-01

Because of the widespread distribution of fibrillin 1 in the body, Marfan syndrome (MFS) affects virtually every system. The expression of this single dominantly inherited gene is variable within a family, and between families. There is some genotype-phenotype correlation which is helpful in guiding long-term prognosis, and management. In general gene mutations have been reported in clusters, with those having mainly ocular manifestations occurring in exons 1 to 15 of this 65-exon gene; those causing cardiac problems often involving cysteine replacement in a calcium binding EGF-like sequence; the most severe mutations occurring in exons 25–32, causing neonatal MFS diagnosed at birth, and severe enough to cause death frequently before the age of 2. Other correlations will certainly be found in future. This condition is progressive, and the manifestations unfold according to age. For example, if the lens is going to dislocate this usually occurs by age 10; scoliosis usually presents itself between the ages of 8 and 15; height should be monitored carefully between the onset of puberty and cessation of growth approximately age 17 or 18. Holistic care should be offered by one doctor who oversees the patient’s welfare. This should be a paediatrician, paediatric cardiologist, or general practitioner in the case of an affected child. Thereafter, the physician in charge of the most seriously affected system should be aware that other systems need to be managed through a referral network. PMID:29270372

Robust Guaranteed Cost Observer Design for Singular Markovian Jump Time-Delay Systems with Generally Incomplete Transition Probability

Directory of Open Access Journals (Sweden)

Yanbo Li

2014-01-01

Full Text Available This paper is devoted to the investigation of the design of robust guaranteed cost observer for a class of linear singular Markovian jump time-delay systems with generally incomplete transition probability. In this singular model, each transition rate can be completely unknown or only its estimate value is known. Based on stability theory of stochastic differential equations and linear matrix inequality (LMI technique, we design an observer to ensure that, for all uncertainties, the resulting augmented system is regular, impulse free, and robust stochastically stable with the proposed guaranteed cost performance. Finally, a convex optimization problem with LMI constraints is formulated to design the suboptimal guaranteed cost filters for linear singular Markovian jump time-delay systems with generally incomplete transition probability.

Role of complementary correlations in the evolution of classical and quantum correlations under Markovian decoherence

International Nuclear Information System (INIS)

Deb, Prasenjit; Banik, Manik

2015-01-01

Quantum correlation lies at the very heart of almost all of the non-classical phenomena exhibited by quantum systems composed of two or more subsystems. In recent times it has been pointed out that there is a kind of quantum correlation, namely discord, which is more general than entanglement. Some authors have investigated the phenomenon that for certain initial states the quantum correlations as well as the classical correlations exhibit sudden change under simple Markovian noise. We show that this dynamical behavior of the correlations of both types can be explained using the idea of complementary correlations. We also show that though a certain class of mixed entangled states can resist the monotonic decay of quantum correlations, this is not true for all mixed states. Moreover, pure entangled states of two qubits will never exhibit such sudden change. (paper)

The Influence of Manifest Strabismus and Stereoscopic Vision on Non-Verbal Abilities of Visually Impaired Children

Science.gov (United States)

Gligorovic, Milica; Vucinic, Vesna; Eskirovic, Branka; Jablan, Branka

2011-01-01

This research was conducted in order to examine the influence of manifest strabismus and stereoscopic vision on non-verbal abilities of visually impaired children aged between 7 and 15. The sample included 55 visually impaired children from the 1st to the 6th grade of elementary schools for visually impaired children in Belgrade. RANDOT stereotest…

Memory-induced acceleration and slowdown of barrier crossing

Science.gov (United States)

Kappler, Julian; Daldrop, Jan O.; Brünig, Florian N.; Boehle, Moritz D.; Netz, Roland R.

2018-01-01

We study the mean first-passage time τMFP for the barrier crossing of a single massive particle with non-Markovian memory by Langevin simulations in one dimension. In the Markovian limit of short memory time τΓ, the expected Kramers turnover between the overdamped (high-friction) and the inertial (low-friction) limits is recovered. Compared to the Markovian case, we find barrier crossing to be accelerated for intermediate memory time, while for long memory time, barrier crossing is slowed down and τMFP increases with τΓ as a power law τM F P˜τΓ2. Both effects are derived from an asymptotic propagator analysis: while barrier crossing acceleration at intermediate memory can be understood as an effective particle mass reduction, slowing down for long memory is caused by the slow kinetics of energy diffusion. A simple and globally accurate heuristic formula for τMFP in terms of all relevant time scales of the system is presented and used to establish a scaling diagram featuring the Markovian overdamped and the Markovian inertial regimes, as well as the non-Markovian intermediate memory time regime where barrier crossing is accelerated and the non-Markovian long memory time regime where barrier crossing is slowed down.

Markovian description of unbiased polymer translocation

International Nuclear Information System (INIS)

Mondaini, Felipe; Moriconi, L.

2012-01-01

We perform, with the help of cloud computing resources, extensive Langevin simulations which provide compelling evidence in favor of a general Markovian framework for unbiased three-dimensional polymer translocation. Our statistical analysis consists of careful evaluations of (i) two-point correlation functions of the translocation coordinate and (ii) the empirical probabilities of complete polymer translocation (taken as a function of the initial number of monomers on a given side of the membrane). We find good agreement with predictions derived from the Markov chain approach recently addressed in the literature by the present authors. -- Highlights: ► We investigate unbiased polymer translocation through membrane pores. ► Large statistical ensembles have been produced with the help of cloud computing resources. ► We evaluate the two-point correlation function of the translocation coordinate. ► We evaluate empirical probabilities for complete polymer translocation. ► Unbiased polymer translocation is described as a Markov stochastic process.

Markovian description of unbiased polymer translocation

Energy Technology Data Exchange (ETDEWEB)

Mondaini, Felipe [Instituto de Física, Universidade Federal do Rio de Janeiro, C.P. 68528, 21945-970 Rio de Janeiro, RJ (Brazil); Centro Federal de Educação Tecnológica Celso Suckow da Fonseca, UnED Angra dos Reis, Angra dos Reis, 23953-030, RJ (Brazil); Moriconi, L., E-mail: moriconi@if.ufrj.br [Instituto de Física, Universidade Federal do Rio de Janeiro, C.P. 68528, 21945-970 Rio de Janeiro, RJ (Brazil)

2012-10-01

We perform, with the help of cloud computing resources, extensive Langevin simulations which provide compelling evidence in favor of a general Markovian framework for unbiased three-dimensional polymer translocation. Our statistical analysis consists of careful evaluations of (i) two-point correlation functions of the translocation coordinate and (ii) the empirical probabilities of complete polymer translocation (taken as a function of the initial number of monomers on a given side of the membrane). We find good agreement with predictions derived from the Markov chain approach recently addressed in the literature by the present authors. -- Highlights: ► We investigate unbiased polymer translocation through membrane pores. ► Large statistical ensembles have been produced with the help of cloud computing resources. ► We evaluate the two-point correlation function of the translocation coordinate. ► We evaluate empirical probabilities for complete polymer translocation. ► Unbiased polymer translocation is described as a Markov stochastic process.

The Spectrum of Neurological Manifestations Associated with Gaucher Disease

Directory of Open Access Journals (Sweden)

Tamanna Roshan Lal

2017-03-01

Full Text Available Gaucher disease, the most common lysosomal storage disorder, is due to a deficiency in the enzyme glucocerebrosidase. This leads to the accumulation of its normal substrate, glucocerebroside, in tissue macrophages, affecting the hematological, visceral, bone and neurologic systems. Gaucher disease is classified into three broad phenotypes based upon the presence or absence of neurological involvement: type 1 (non-neuronopathic, type 2 (acute neuronopathic, and type 3 (subacute neuronopathic. Phenotypically, there is a wide spectrum of visceral and neurological manifestations. Enzyme replacement is effective in managing the visceral disease; however, treating the neurological manifestations has proved to be more challenging. This review discusses the various neurological manifestations encountered in Gaucher disease, and provides a brief overview regarding the treatment and ongoing research challenges.

H∞ Filtering for Networked Markovian Jump Systems with Multiple Stochastic Communication Delays

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Hui Dong

2015-01-01

Full Text Available This paper is concerned with the H∞ filtering for a class of networked Markovian jump systems with multiple communication delays. Due to the existence of communication constraints, the measurement signal cannot arrive at the filter completely on time, and the stochastic communication delays are considered in the filter design. Firstly, a set of stochastic variables is introduced to model the occurrence probabilities of the delays. Then based on the stochastic system approach, a sufficient condition is obtained such that the filtering error system is stable in the mean-square sense and with a prescribed H∞ disturbance attenuation level. The optimal filter gain parameters can be determined by solving a convex optimization problem. Finally, a simulation example is given to show the effectiveness of the proposed filter design method.

Closed hierarchy of correlations in Markovian open quantum systems

International Nuclear Information System (INIS)

Žunkovič, Bojan

2014-01-01

We study the Lindblad master equation in the space of operators and provide simple criteria for closeness of the hierarchy of equations for correlations. We separately consider the time evolution of closed and open systems and show that open systems satisfying the closeness conditions are not necessarily of Gaussian type. In addition, we show that dissipation can induce the closeness of the hierarchy of correlations in interacting quantum systems. As an example we study an interacting optomechanical model, the Fermi–Hubbard model, and the Rabi model, all coupled to a fine-tuned Markovian environment and obtain exact analytic expressions for the time evolution of two-point correlations. (paper)

State estimation for discrete-time Markovian jumping neural networks with mixed mode-dependent delays

International Nuclear Information System (INIS)

Liu Yurong; Wang Zidong; Liu Xiaohui

2008-01-01

In this Letter, we investigate the state estimation problem for a new class of discrete-time neural networks with Markovian jumping parameters as well as mode-dependent mixed time-delays. The parameters of the discrete-time neural networks are subject to the switching from one mode to another at different times according to a Markov chain, and the mixed time-delays consist of both discrete and distributed delays that are dependent on the Markovian jumping mode. New techniques are developed to deal with the mixed time-delays in the discrete-time setting, and a novel Lyapunov-Krasovskii functional is put forward to reflect the mode-dependent time-delays. Sufficient conditions are established in terms of linear matrix inequalities (LMIs) that guarantee the existence of the state estimators. We show that both the existence conditions and the explicit expression of the desired estimator can be characterized in terms of the solution to an LMI. A numerical example is exploited to show the usefulness of the derived LMI-based conditions

Neural Network-Based Passive Filtering for Delayed Neutral-Type Semi-Markovian Jump Systems.

Science.gov (United States)

Shi, Peng; Li, Fanbiao; Wu, Ligang; Lim, Cheng-Chew

2017-09-01

This paper investigates the problem of exponential passive filtering for a class of stochastic neutral-type neural networks with both semi-Markovian jump parameters and mixed time delays. Our aim is to estimate the states by designing a Luenberger-type observer, such that the filter error dynamics are mean-square exponentially stable with an expected decay rate and an attenuation level. Sufficient conditions for the existence of passive filters are obtained, and a convex optimization algorithm for the filter design is given. In addition, a cone complementarity linearization procedure is employed to cast the nonconvex feasibility problem into a sequential minimization problem, which can be readily solved by the existing optimization techniques. Numerical examples are given to demonstrate the effectiveness of the proposed techniques.

Nelson's stochastic quantization of free linearized gravitational field and its Markovian structure

International Nuclear Information System (INIS)

Lim, S.C.

1983-05-01

It is shown that by applying Nelson's stochastic quantization scheme to free linearized gravitational field tensor one can associate with the resulting stochastic system a stochastic tensor field which coincides with the ''space'' part of the Riemannian tensor in Euclidean space-time. However, such a stochastic field fails to satisfy the Markov property. Instead, it satisfies the reflection positivity. The Markovian structure of the stochastic fields associated with the electromagnetic field is also discussed. (author)

Suppression of thermal noise in a non-Markovian random velocity field

International Nuclear Information System (INIS)

Ueda, Masahiko

2016-01-01

We study the diffusion of Brownian particles in a Gaussian random velocity field with short memory. By extending the derivation of an effective Fokker–Planck equation for the Lanvegin equation with weakly colored noise to a random velocity-field problem, we find that the effect of thermal noise on particles is suppressed by the existence of memory. We also find that the renormalization effect for the relative diffusion of two particles is stronger than that for single-particle diffusion. The results are compared with those of molecular dynamics simulations. (paper: classical statistical mechanics, equilibrium and non-equilibrium)

Memory effects in turbulent diffusion

International Nuclear Information System (INIS)

Zagorodny, A.G.; Weiland, J.; Wilhelmsson, H.

1993-01-01

A non-Markovian approach is proposed for the derivation of the diffusion coefficient of saturated turbulence. A memory term accounting for nonlocal coherence effects is introduced in a new attempt to describe the transition between weak and strong turbulence. The result compares favourably with recent experiments as well as mode coupling simulations of fusion plasmas. (14 refs.)

Two-dimensional spectroscopy for harmonic vibrational modes with nonlinear system-bath interactions. II. Gaussian-Markovian case

NARCIS (Netherlands)

Tanimura, Y; Steffen, T

2000-01-01

The relaxation processes in a quantum system nonlinearly coupled to a harmonic Gaussian-Markovian heat bath are investigated by the quantum Fokker-Planck equation in the hierarchy form. This model describes frequency fluctuations in the quantum system with an arbitrary correlation time and thus

Reliability Analysis of Wireless Sensor Networks Using Markovian Model

Directory of Open Access Journals (Sweden)

Jin Zhu

2012-01-01

Full Text Available This paper investigates reliability analysis of wireless sensor networks whose topology is switching among possible connections which are governed by a Markovian chain. We give the quantized relations between network topology, data acquisition rate, nodes' calculation ability, and network reliability. By applying Lyapunov method, sufficient conditions of network reliability are proposed for such topology switching networks with constant or varying data acquisition rate. With the conditions satisfied, the quantity of data transported over wireless network node will not exceed node capacity such that reliability is ensured. Our theoretical work helps to provide a deeper understanding of real-world wireless sensor networks, which may find its application in the fields of network design and topology control.

Dynamics of non-Markovianity in the presence of a driving field

Indian Academy of Sciences (India)

In some conditions, it is shown that in the presence of a driving field, the $N_{\\rm BLP} increases in the resonance and non-resonance limits. We have also found the exact solution of the master equation in order to investigate the effect of temperature- and environment excited states. We have shown that the behaviour of ...

Manifestation of meibomian gland dysfunction in patients with Sjögren's syndrome, non-Sjögren's dry eye, and non-dry eye controls.

Science.gov (United States)

Kang, Yeon Soo; Lee, Hyo Seok; Li, Ying; Choi, Won; Yoon, Kyung Chul

2018-06-01

To evaluate the manifestation of meibomian gland dysfunction in patients with Sjögren's syndrome (SS), non-Sjögren's syndrome dry eye (non-SS) patients, and non-dry eye controls. We recruited 31 participants with SS dry eye, 30 participants with non-SS dry eye, and 35 healthy controls without dry eye symptoms. Noninvasive tear breakup time (NITBUT) and meibomian gland dropout score (meiboscore) were measured using the Oculus Keratograph 5 M. Meibomian gland expressibility and secretion quality were evaluated via slit lamp biomicroscopy. The correlation between measurements was analyzed. NITBUT was lower, and the meiboscore, meibomian gland expressibility, and secretion quality scores were significantly higher in the SS and non-SS groups than in the control group (p dry eye controls. SS patients had more severe meibomian gland dysfunction with poorer mean meiboscore and meibomian gland expressibility than non-SS patients.

EXTRAGASTRIC AND ORODENTAL MANIFESTATIONS IN PEDIATRIC INFECTION WITH HELICOBACTER PYLORI. A REVIEW

OpenAIRE

Smaranda DIACONESCU; Raluca STANCA; Maria BOLAT

2015-01-01

Helicobacter pylori is a worlwide spread infection mostly manifested in childhood. Many - both invasive and non-invasive diagnostic tests - are now available,. The colonisation effect of gastric mucosa and its consequences are well known and studied. H. pylori can also induce extra-gastric manifestations, like iron-deficiency anemia. The role of oral cavity colonisation is not clearly defined, several studies stating that the oral cavity represents a reservoir for H. pyloris. The presence of ...

Synchronization of Markovian jumping inertial neural networks and its applications in image encryption.

Science.gov (United States)

Prakash, M; Balasubramaniam, P; Lakshmanan, S

2016-11-01

This study is mainly concerned with the problem on synchronization criteria for Markovian jumping time delayed bidirectional associative memory neural networks and their applications in secure image communications. Based on the variable transformation method, the addressed second order differential equations are transformed into first order differential equations. Then, by constructing a suitable Lyapunov-Krasovskii functional and based on integral inequalities, the criteria which ensure the synchronization between the uncontrolled system and controlled system are established through designed feedback controllers and linear matrix inequalities. Further, the proposed results proved that the error system is globally asymptotically stable in the mean square. Moreover, numerical illustrations are provided to validate the effectiveness of the derived analytical results. Finally, the application of addressed system is explored via image encryption/decryption process. Copyright © 2016 Elsevier Ltd. All rights reserved.

An application of superpositions of two-state Markovian sources to the modelling of self-similar behaviour

DEFF Research Database (Denmark)

Andersen, Allan T.; Nielsen, Bo Friis

1997-01-01

We present a modelling framework and a fitting method for modelling second order self-similar behaviour with the Markovian arrival process (MAP). The fitting method is based on fitting to the autocorrelation function of counts a second order self-similar process. It is shown that with this fittin...

Optimizing Maintenance Planning in the Production Industry Using the Markovian Approach

Directory of Open Access Journals (Sweden)

B Kareem

2012-12-01

Full Text Available Maintenance is an essential activity in every manufacturing establishment, as manufacturing effectiveness counts on the functionality of production equipment and machinery in terms of their productivity and operational life. Maintenance cost minimization can be achieved by adopting an appropriate maintenance planning policy. This paper applies the Markovian approach to maintenance planning decision, thereby generating optimal maintenance policy from the identified alternatives over a specified period of time. Markov chains, transition matrices, decision processes, and dynamic programming models were formulated for the decision problem related to maintenance operations of a cable production company. Preventive and corrective maintenance data based on workloads and costs, were collected from the company and utilized in this study. The result showed variability in the choice of optimal maintenance policy that was adopted in the case study. Post optimality analysis of the process buttressed the claim. The proposed approach is promising for solving the maintenance scheduling decision problems of the company.

Manifest dream content as a possible predictor of suicidality.

Science.gov (United States)

Glucksman, Myron L

2014-12-01

The prediction of suicidal intent remains a clinical problem. This presentation illustrates that a distinction may be made between the manifest dream reports of patients who are potentially or acutely suicidal and those who are not. A review of the literature reveals that the manifest dream reports of clinically depressed, non-suicidal individuals differ from those who are depressed and acutely suicidal. The former contain themes of loss, disappointment, rejection, helplessness, hopelessness, failure, and death. The latter contain themes of dying, death, destruction, and violence directed toward the dreamer or others, as well as hopelessness and helplessness. The author collected manifest dream reports from three clinically depressed, non-suicidal patients and three clinically depressed, potentially or acutely suicidal patients. There are apparent differences between the themes of manifest dream reports in the clinically depressed, non-suicidal patients and the clinically depressed, potentially or acutely suicidal patients. The former contain themes of death, loss, rejection, vulnerability, hopelessness, and helplessness. The latter contain themes of active harm or violence (specifically toward the dreamer), dying or being dead, aloneness, vulnerability, hopelessness, and helplessness. Clinical cases and corresponding manifest dream reports are presented. Although this is a preliminary study, it is possible that manifest dream content may be used as one of the predictors of suicidality, in conjunction with latent dream content, diagnosis, life circumstance, and clinical status.

Haematological manifestations of lupus

Science.gov (United States)

Fayyaz, Anum; Igoe, Ann; Kurien, Biji T; Danda, Debashish; James, Judith A; Stafford, Haraldine A; Scofield, R Hal

2015-01-01

Our purpose was to compile information on the haematological manifestations of systemic lupus erythematosus (SLE), namely leucopenia, lymphopenia, thrombocytopenia, autoimmune haemolytic anaemia (AIHA), thrombotic thrombocytopenic purpura (TTP) and myelofibrosis. During our search of the English-language MEDLINE sources, we did not place a date-of-publication constraint. Hence, we have reviewed previous as well as most recent studies with the subject heading SLE in combination with each manifestation. Neutropenia can lead to morbidity and mortality from increased susceptibility to infection. Severe neutropenia can be successfully treated with granulocyte colony-stimulating factor. While related to disease activity, there is no specific therapy for lymphopenia. Severe lymphopenia may require the use of prophylactic therapy to prevent select opportunistic infections. Isolated idiopathic thrombocytopenic purpura maybe the first manifestation of SLE by months or even years. Some manifestations of lupus occur more frequently in association with low platelet count in these patients, for example, neuropsychiatric manifestation, haemolytic anaemia, the antiphospholipid syndrome and renal disease. Thrombocytopenia can be regarded as an important prognostic indicator of survival in patients with SLE. Medical, surgical and biological treatment modalities are reviewed for this manifestation. First-line therapy remains glucocorticoids. Through our review, we conclude glucocorticoids do produce a response in majority of patients initially, but sustained response to therapy is unlikely. Glucocorticoids are used as first-line therapy in patients with SLE with AIHA, but there is no conclusive evidence to guide second-line therapy. Rituximab is promising in refractory and non-responding AIHA. TTP is not recognised as a criteria for classification of SLE, but there is a considerable overlap between the presenting features of TTP and SLE, and a few patients with SLE have concurrent

Musculoskeletal manifestations of the antiphospholipid syndrome.

Science.gov (United States)

Noureldine, M H A; Khamashta, M A; Merashli, M; Sabbouh, T; Hughes, G R V; Uthman, I

2016-04-01

The scope of clinical and laboratory manifestations of the antiphospholipid syndrome (APS) has increased dramatically since its discovery in 1983, where any organ system can be involved. Musculoskeletal complications are consistently reported in APS patients, not only causing morbidity and mortality, but also affecting their quality of life. We reviewed all English papers on APS involvement in the musculoskeletal system using Google Scholar and Pubmed; all reports are summarized in a table in this review. The spectrum of manifestations includes arthralgia/arthritis, avascular necrosis of bone, bone marrow necrosis, complex regional pain syndrome type-1, muscle infarction, non-traumatic fractures, and osteoporosis. Some of these manifestations were reported in good quality studies, some of which showed an association between aPL-positivity and the occurrence of these manifestations, while others were merely described in case reports. © The Author(s) 2016.

Osteoarticular manifestations of celiac disease and non-celiac gluten hypersensitivity.

Science.gov (United States)

Dos Santos, Stéphanie; Lioté, Frédéric

2017-05-01

Celiac disease is a chronic inflammatory autoimmune enteropathy based disorder that is triggered by the ingestion of gluten in genetically susceptible individuals. The global prevalence of 1% to 2% represents only the tip of the iceberg. The diagnosis is confirmed by positive specific antibody, anti-transglutaminase or anti-endomysium, specific lesions of the small intestine and a response to strict gluten-free diet. The diagnosis is difficult and often delayed because the clinical variability is very large, ranging from digestive clinical presentation "classic" to "atypical" symptoms, often extra-intestinal, that are sometimes attributed to a concomitant disease or a complication. Among them, there are frequent musculoskeletal manifestations such as osteoporosis and osteomalacia. In the absence of risk factor, osteoporosis, in a premenopausal women or in a man less than 55 years, more is if it is severe and refractory to medications, need to rheumatologists on the track of celiac disease in the absence of digestive symptoms. Osteomalacia is related to secondary hypovitaminosis D malabsorption. Supplementation by calcifediol, water-soluble vitamin D, may be indicated. Celiac disease is associated with an autoimmune disease in almost 1/3 of the cases. Knowing these potential associations allows earlier diagnosis in patients whose only manifestation, a concomitant disease. Anemia, chronic fatigue or unexplained polyarthralgia are symptoms associated with celiac disease to look for specific antibodies. The aim of early diagnosis is to prevent the emergence of other systemic disorders and avoid complications such as bone fractures and cancer, especially intestinal lymphoma. Non-celiac gluten intolerance is a new entity defined by symptomatology similar to that of celiac disease induced by the ingestion of gluten and disappearing after crowding-out, among patients without specific antibodies and without intestinal lesion of celiac disease. This entity is a cause, at

Lévy stable noise-induced transitions: stochastic resonance, resonant activation and dynamic hysteresis

International Nuclear Information System (INIS)

Dybiec, Bartłomiej; Gudowska-Nowak, Ewa

2009-01-01

A standard approach to analysis of noise-induced effects in stochastic dynamics assumes a Gaussian character of the noise term describing interaction of the analyzed system with its complex surroundings. An additional assumption about the existence of timescale separation between the dynamics of the measured observable and the typical timescale of the noise allows external fluctuations to be modeled as temporally uncorrelated and therefore white. However, in many natural phenomena the assumptions concerning the above mentioned properties of 'Gaussianity' and 'whiteness' of the noise can be violated. In this context, in contrast to the spatiotemporal coupling characterizing general forms of non-Markovian or semi-Markovian Lévy walks, so called Lévy flights correspond to the class of Markov processes which can still be interpreted as white, but distributed according to a more general, infinitely divisible, stable and non-Gaussian law. Lévy noise-driven non-equilibrium systems are known to manifest interesting physical properties and have been addressed in various scenarios of physical transport exhibiting a superdiffusive behavior. Here we present a brief overview of our recent investigations aimed at understanding features of stochastic dynamics under the influence of Lévy white noise perturbations. We find that the archetypal phenomena of noise-induced ordering are robust and can be detected also in systems driven by memoryless, non-Gaussian, heavy-tailed fluctuations with infinite variance

Implied Stopping Rules for American Basket Options from Markovian Projection

KAUST Repository

Bayer, Christian; Hä ppö lä , Juho; Tempone, Raul

2017-01-01

This work addresses the problem of pricing American basket options in a multivariate setting, which includes among others, the Bachelier and the Black-Scholes models. In high dimensions, nonlinear partial differential equation methods for solving the problem become prohibitively costly due to the curse of dimensionality. Instead, this work proposes to use a stopping rule that depends on the dynamics of a low-dimensional Markovian projection of the given basket of assets. It is shown that the ability to approximate the original value function by a lower-dimensional approximation is a feature of the dynamics of the system and is unaffected by the path-dependent nature of the American basket option. Assuming that we know the density of the forward process and using the Laplace approximation, we first efficiently evaluate the diffusion coefficient corresponding to the low-dimensional Markovian projection of the basket. Then, we approximate the optimal early-exercise boundary of the option by solving a Hamilton-Jacobi-Bellman partial differential equation in the projected, low-dimensional space. The resulting near-optimal early-exercise boundary is used to produce an exercise strategy for the high-dimensional option, thereby providing a lower bound for the price of the American basket option. A corresponding upper bound is also provided. These bounds allow to assess the accuracy of the proposed pricing method. Indeed, our approximate early-exercise strategy provides a straightforward lower bound for the American basket option price. Following a duality argument due to Rogers, we derive a corresponding upper bound solving only the low-dimensional optimal control problem. Numerically, we show the feasibility of the method using baskets with dimensions up to fifty. In these examples, the resulting option price relative errors are only of the order of few percent.

Implied Stopping Rules for American Basket Options from Markovian Projection

KAUST Repository

Bayer, Christian

2017-05-01

This work addresses the problem of pricing American basket options in a multivariate setting, which includes among others, the Bachelier and the Black-Scholes models. In high dimensions, nonlinear partial differential equation methods for solving the problem become prohibitively costly due to the curse of dimensionality. Instead, this work proposes to use a stopping rule that depends on the dynamics of a low-dimensional Markovian projection of the given basket of assets. It is shown that the ability to approximate the original value function by a lower-dimensional approximation is a feature of the dynamics of the system and is unaffected by the path-dependent nature of the American basket option. Assuming that we know the density of the forward process and using the Laplace approximation, we first efficiently evaluate the diffusion coefficient corresponding to the low-dimensional Markovian projection of the basket. Then, we approximate the optimal early-exercise boundary of the option by solving a Hamilton-Jacobi-Bellman partial differential equation in the projected, low-dimensional space. The resulting near-optimal early-exercise boundary is used to produce an exercise strategy for the high-dimensional option, thereby providing a lower bound for the price of the American basket option. A corresponding upper bound is also provided. These bounds allow to assess the accuracy of the proposed pricing method. Indeed, our approximate early-exercise strategy provides a straightforward lower bound for the American basket option price. Following a duality argument due to Rogers, we derive a corresponding upper bound solving only the low-dimensional optimal control problem. Numerically, we show the feasibility of the method using baskets with dimensions up to fifty. In these examples, the resulting option price relative errors are only of the order of few percent.

Markovian Interpretations of Dual Retrieval Processes.

Science.gov (United States)

Gomes, C F A; Brainerd, C J; Nakamura, K; Reyna, V F

2014-04-01

A half-century ago, at the dawn of the all-or-none learning era, Estes showed that finite Markov chains supply a tractable, comprehensive framework for discrete-change data of the sort that he envisioned for shifts in conditioning states in stimulus sampling theory. Shortly thereafter, such data rapidly accumulated in many spheres of human learning and animal conditioning, and Estes' work stimulated vigorous development of Markov models to handle them. A key outcome was that the data of the workhorse paradigms of episodic memory, recognition and recall, proved to be one- and two-stage Markovian, respectively, to close approximations. Subsequently, Markov modeling of recognition and recall all but disappeared from the literature, but it is now reemerging in the wake of dual-process conceptions of episodic memory. In recall, in particular, Markov models are being used to measure two retrieval operations (direct access and reconstruction) and a slave familiarity operation. In the present paper, we develop this family of models and present the requisite machinery for fit evaluation and significance testing. Results are reviewed from selected experiments in which the recall models were used to understand dual memory processes.

Markovian Interpretations of Dual Retrieval Processes

Science.gov (United States)

Gomes, C. F. A.; Nakamura, K.; Reyna, V. F.

2013-01-01

A half-century ago, at the dawn of the all-or-none learning era, Estes showed that finite Markov chains supply a tractable, comprehensive framework for discrete-change data of the sort that he envisioned for shifts in conditioning states in stimulus sampling theory. Shortly thereafter, such data rapidly accumulated in many spheres of human learning and animal conditioning, and Estes’ work stimulated vigorous development of Markov models to handle them. A key outcome was that the data of the workhorse paradigms of episodic memory, recognition and recall, proved to be one- and two-stage Markovian, respectively, to close approximations. Subsequently, Markov modeling of recognition and recall all but disappeared from the literature, but it is now reemerging in the wake of dual-process conceptions of episodic memory. In recall, in particular, Markov models are being used to measure two retrieval operations (direct access and reconstruction) and a slave familiarity operation. In the present paper, we develop this family of models and present the requisite machinery for fit evaluation and significance testing. Results are reviewed from selected experiments in which the recall models were used to understand dual memory processes. PMID:24948840

Markovian Model in High Order Sequence Prediction From Log-Motif Patterns in Agbada Paralic Section, Niger Delta, Nigeria

International Nuclear Information System (INIS)

Olabode, S. O.; Adekoya, J. A.

2002-01-01

Markovian model in the elucidation of high order sequence was applied to repetitive events of regressive and transgressive phases in the Agbada paralic section Niger Delta. The repetitive events are made up of delta front, delta topset and fluvio-deltaic sediments. The sediments consist of sands, sandstones, siltstones and shales in various proportions. Five wells: MN1, AA1, NP2, NP6 and NP8 were studied.Summary of biostratigraphic report and well log-motif patterns was used to delineate the third order depositional sequences in the wells.Various Markovian properties - observed transition frequency matrix, observed transition probability matrix, fixed probability vector, expected random matrix (randomised transition matrix) and difference matrix were determined for stacked high order sequence (high frequency cyclic events) nested within the third-order sequences using the log-motif patterns for the various sand bodies and shales. Flow diagrams were constructed for each of the depositional sequences to know the likely occurrence of number of cycles.Upward transition matrix between the log-motif patterns and flow diagram to elucidate cyclicity show that the overall regressive sequence of the Niger Delta has been modified by deltaic depositional elements and fluctuations in sea level. The predictions of higher order sequence within third order sequences from Markovian Properties provide good basis for correlation within the depositional sequences. The model has also been used to decipher the dominant depositional processes during the formation of the sequences. Discrete reservoir intervals and seal potentials within the sequences were also predicted from the flow diagrams constructed

[Lyme disease--clinical manifestations and treatment].

Science.gov (United States)

Stock, Ingo

2016-05-01

Lyme disease (Lyme borreliosis) is a systemic infectious disease that can present in a variety of clinical manifestations. The disease is caused by a group of spirochaetes--Borrelia burgdorferi sensu lato or Lyme borrelia--that are transmitted to humans by the bite of Ixodes ticks. Lyme disease is the most common arthropode-borne infectious disease in many European countries including Germany. Early localized infection is typically manifested by an erythema migrans skin lesion, in rarer cases as a borrelial lymphocytoma. The most common early disseminated manifestation is (early) neuroborreliosis. In adults, neuroborreliosis appears typically as meningoradiculoneuritis. Neuroborreliosis in children, however, is typically manifested by meningitis. In addition, multiple erythema migrans lesions and Lyme carditis occur relatively frequently. The most common manifestation oflate Lyme disease is Lyme arthritis. Early manifestations (and usually also late manifestations) of Lyme disease can be treated successfully by application of suitable antibacterial agents. For the treatment of Lyme disease, doxycycline, certain penicillins such as amoxicillin and some cephalosporins (ceftriaxone, cefotaxime, cefuroxime axetil) are recommended in current guidelines. A major challenge is the treatment of chronic, non-specific disorders, i. e., posttreatment Lyme disease syndrome and "chronic Lyme disease". Prevention of Lyme disease is mainly accomplished by protecting against tick bites. Prophylactic administration of doxycycline after tick bites is generally not recommended in Germany. There is no vaccine available for human beings.

Tightness Entropic Uncertainty Relation in Quantum Markovian-Davies Environment

Science.gov (United States)

Zhang, Jun; Liu, Liang; Han, Yan

2018-05-01

In this paper, we investigate the tightness of entropic uncertainty relation in the absence (presence) of the quantum memory which the memory particle being weakly coupled to a decohering Davies-type Markovian environment. The results show that the tightness of the quantum uncertainty relation can be controlled by the energy relaxation time F, the dephasing time G and the rescaled temperature p, the perfect tightness can be arrived by dephasing and energy relaxation satisfying F = 2G and p = 1/2. In addition, the tightness of the memory-assisted entropic uncertainty relation and the entropic uncertainty relation can be influenced mainly by the purity. While in memory-assisted model, the purity and quantum correlation can also influence the tightness actively while the quantum entanglement can influence the tightness slightly.

Ocular manifestations of leptospirosis

Directory of Open Access Journals (Sweden)

Rathinam S

2005-01-01

Full Text Available Leptospiral uveitis is a common entity in tropical countries. Ocular manifestations are noted in the second phase of illness, but these remain under-diagnosed mainly because of the prolonged symptom-free period that separates the systemic manifestations from detection of ocular manifestations.Varying ophthalmic presentations and the intrinsic nature of different types of uveitis to mimic one another also challenge the accuracy of the diagnosis. Of the individual ocular signs, the combination of acute, non-granulomatous, panuveitis, hypopyon, vasculitis, optic disc edema, membranous vitreous opacities and absence of choroiditis or retinitis have high predictive value for the clinical diagnosis of leptospiral uveitis. Geographic location of the patient, occupation, socio-economic status, risk factors related to exposure, past history of fever or jaundice also aid in diagnosis.Steroids are the mainstay of treatment for leptospiral uveitis. Depending upon the severity and anatomical location of inflammatory lesion, topical, peri-ocular and/or systemic steroids are given. The prognosis is generally good, even when the inflammation is severe.

Three-dimensional photodissociation in strong laser fields: Memory-kernel effective-mode expansion

International Nuclear Information System (INIS)

Li Xuan; Thanopulos, Ioannis; Shapiro, Moshe

2011-01-01

We introduce a method for the efficient computation of non-Markovian quantum dynamics for strong (and time-dependent) system-bath interactions. The past history of the system dynamics is incorporated by expanding the memory kernel in exponential functions thereby transforming in an exact fashion the non-Markovian integrodifferential equations into a (larger) set of ''effective modes'' differential equations (EMDE). We have devised a method which easily diagonalizes the EMDE, thereby allowing for the efficient construction of an adiabatic basis and the fast propagation of the EMDE in time. We have applied this method to three-dimensional photodissociation of the H 2 + molecule by strong laser fields. Our calculations properly include resonance-Raman scattering via the continuum, resulting in extensive rotational and vibrational excitations. The calculated final kinetic and angular distribution of the photofragments are in overall excellent agreement with experiments, both when transform-limited pulses and when chirped pulses are used.

Synchronization of stochastic delayed neural networks with markovian switching and its application.

Science.gov (United States)

Tang, Yang; Fang, Jian-An; Miao, Qing-Ying

2009-02-01

In this paper, the problem of adaptive synchronization for a class of stochastic neural networks (SNNs) which involve both mixed delays and Markovian jumping parameters is investigated. The mixed delays comprise the time-varying delays and distributed delays, both of which are mode-dependent. The stochastic perturbations are described in terms of Browian motion. By the adaptive feedback technique, several sufficient criteria have been proposed to ensure the synchronization of SNNs in mean square. Moreover, the proposed adaptive feedback scheme is applied to the secure communication. Finally, the corresponding simulation results are given to demonstrate the usefulness of the main results obtained.

SIMULTANEOUS MULTI-BAND DETECTION OF LOW SURFACE BRIGHTNESS GALAXIES WITH MARKOVIAN MODELING

International Nuclear Information System (INIS)

Vollmer, B.; Bonnarel, F.; Louys, M.; Perret, B.; Petremand, M.; Lavigne, F.; Collet, Ch.; Van Driel, W.; Sabatini, S.; MacArthur, L. A.

2013-01-01

We present to the astronomical community an algorithm for the detection of low surface brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings—typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. The application of the method to two and three bands simultaneously was tested on simulated images. Based on our tests, we are confident that we can detect LSB galaxies down to a central surface brightness level of only 1.5 times the standard deviation from the mean pixel value in the image background. To assess the robustness of our method, the method was applied to a set of 18 B- and I-band images (covering 1.3 deg 2 in total) of the Virgo Cluster to which Sabatini et al. previously applied a matched-filter dwarf LSB galaxy search algorithm. We have detected all 20 objects from the Sabatini et al. catalog which we could classify by eye as bona fide LSB galaxies. Our method has also detected four additional Virgo Cluster LSB galaxy candidates undetected by Sabatini et al. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (1) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (2) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered ∼20% more mock LSB galaxies and ∼40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of 90% is

CT manifestation of hepatic toxoplasmosis

International Nuclear Information System (INIS)

Mao Qing; Yang Yaying; Bao Yanming; He Bo; Wang Kechao; Song Guangyi; Lu Lin; Wang Xiaoli

2005-01-01

Objective: To study the CT manifestation of hepatic toxoplasmosis, and to provide image basis for its clinical diagnosis. Methods: Three patients with hepatic toxoplasmosis were examined by abdomen MSCT (pre- and post-contrast), and were confirmed by laboratory exams. The images were analyzed with information of clinical manifestation. Results: The positive appearances included the enlargement of liver, patches of multiple scattered low densities. Post-contrast lesions appearances: (1) No significant enhancement. (2) No significant occupying effection, and normal vessels inserting lesion occasionally. Conclusion: CT manifestation of hepar toxoplasmosis are some characteristic. But the diagnosis was made by a combination both clinical manifestation and laboratory exams. (authors)

Improved delay-dependent globally asymptotic stability of delayed uncertain recurrent neural networks with Markovian jumping parameters

International Nuclear Information System (INIS)

Yan, Ji; Bao-Tong, Cui

2010-01-01

In this paper, we have improved delay-dependent stability criteria for recurrent neural networks with a delay varying over a range and Markovian jumping parameters. The criteria improve over some previous ones in that they have fewer matrix variables yet less conservatism. In addition, a numerical example is provided to illustrate the applicability of the result using the linear matrix inequality toolbox in MATLAB. (general)

Markovianity in space and time : [dedicated to Professor Mike Keane on the occasion of his 65th birthday

NARCIS (Netherlands)

M.N.M. van Lieshout (Marie-Colette)

2005-01-01

textabstractMarkov chains in time, such as simple random walks, are at the heart of probability. In space, due to the absence of an obvious definition of past and future, a range of definitions of Markovianity have been proposed. In this paper, after a brief review, we introduce a new concept of

Elastoplasticity: A link between giant vibrations and overdamped motion

International Nuclear Information System (INIS)

Noerenberg, W.

1984-08-01

Elastoplasticity of finite Fermi systems results from a non-markovian coupling between collective and intrinsic degrees of freedom and subsequent equilibration essentially due to two-body collisions. Within a transport-theoretical approach referred to as dissipative diabatic dynamics (DDD), elastoplasticity forms the link between giant vibrations and overdamped motion of nuclei. Observable effects resulting from this non-markovian behaviour in nucleus-nucleus collisions are discussed. (orig.)

QUANTITATIVE EVALUATION OF TAXPAYERS’ BEHAVIOUR OF FISCAL NON-COMPLIANCE MANIFESTED BY TAX EVASION

Directory of Open Access Journals (Sweden)

Elena PĂDUREAN, PhD

2012-09-01

Full Text Available The existence, operation and perspectives of economic-social development of a country are linked to its fiscal system, to its performance and to the fiscal culture of the taxpayers, which formed during the fiscal history of that state. The current state of a contemporary state depends on the history of its fiscal system, on the way in which it has been conceived, on the way it has been adapted to the progressive stages of state development and to the way in which it managed to induce, beyond the feeling of constraint, the fiscal education of the taxpayers supporting the feeling of an efficient utilisation of the levied contributions. In this paper we are trying to make a quantitative evaluation of the Romanian fiscal system in terms of taxpayer‟s behaviour of fiscal non-compliance manifested by tax evasion.

Data-driven non-Markovian closure models

Science.gov (United States)

Kondrashov, Dmitri; Chekroun, Mickaël D.; Ghil, Michael

2015-03-01

This paper has two interrelated foci: (i) obtaining stable and efficient data-driven closure models by using a multivariate time series of partial observations from a large-dimensional system; and (ii) comparing these closure models with the optimal closures predicted by the Mori-Zwanzig (MZ) formalism of statistical physics. Multilayer stochastic models (MSMs) are introduced as both a generalization and a time-continuous limit of existing multilevel, regression-based approaches to closure in a data-driven setting; these approaches include empirical model reduction (EMR), as well as more recent multi-layer modeling. It is shown that the multilayer structure of MSMs can provide a natural Markov approximation to the generalized Langevin equation (GLE) of the MZ formalism. A simple correlation-based stopping criterion for an EMR-MSM model is derived to assess how well it approximates the GLE solution. Sufficient conditions are derived on the structure of the nonlinear cross-interactions between the constitutive layers of a given MSM to guarantee the existence of a global random attractor. This existence ensures that no blow-up can occur for a broad class of MSM applications, a class that includes non-polynomial predictors and nonlinearities that do not necessarily preserve quadratic energy invariants. The EMR-MSM methodology is first applied to a conceptual, nonlinear, stochastic climate model of coupled slow and fast variables, in which only slow variables are observed. It is shown that the resulting closure model with energy-conserving nonlinearities efficiently captures the main statistical features of the slow variables, even when there is no formal scale separation and the fast variables are quite energetic. Second, an MSM is shown to successfully reproduce the statistics of a partially observed, generalized Lotka-Volterra model of population dynamics in its chaotic regime. The challenges here include the rarity of strange attractors in the model's parameter

Asymptotic results for the semi-Markovian random walk with delay

International Nuclear Information System (INIS)

Khaniyev, T.A.; Aliyev, R.T.

2006-12-01

In this study, the semi-Markovian random walk with a discrete interference of chance (X(t) ) is considered and under some weak assumptions the ergodicity of this process is discussed. Characteristic function of the ergodic distribution of X(t) is expressed by means of the probability characteristics of the boundary functionals (N,S N ). Some exact formulas for first and second moments of ergodic distribution of the process X(t) are obtained when the random variable ζ 1 - s, which is describing a discrete interference of chance, has Gamma distribution on the interval [0, ∞) with parameter (α,λ) . Based on these results, the asymptotic expansions with three terms for the first two moments of the ergodic distribution of the process X(t) are obtained, as λ → 0. (author)

Targeted and non-targeted effects of ionizing radiation

Directory of Open Access Journals (Sweden)

Omar Desouky

2015-04-01

Full Text Available For a long time it was generally accepted that effects of ionizing radiation such as cell death, chromosomal aberrations, DNA damage, mutagenesis, and carcinogenesis result from direct ionization of cell structures, particularly DNA, or from indirect damage through reactive oxygen species produced by radiolysis of water, and these biological effects were attributed to irreparable or misrepaired DNA damage in cells directly hit by radiation. Using linear non-threshold model (LNT, possible risks from exposure to low dose ionizing radiation (below 100 mSv are estimated by extrapolating from data obtained after exposure to higher doses of radiation. This model has been challenged by numerous observations, in which cells that were not directly traversed by the ionizing radiation exhibited responses similar to those of the directly irradiated cells. Therefore, it is nowadays accepted that the detrimental effects of ionizing radiation are not restricted only in the irradiated cells, but also to non-irradiated bystander or even distant cells manifesting various biological effects.

Operational Markov Condition for Quantum Processes

Science.gov (United States)

Pollock, Felix A.; Rodríguez-Rosario, César; Frauenheim, Thomas; Paternostro, Mauro; Modi, Kavan

2018-01-01

We derive a necessary and sufficient condition for a quantum process to be Markovian which coincides with the classical one in the relevant limit. Our condition unifies all previously known definitions for quantum Markov processes by accounting for all potentially detectable memory effects. We then derive a family of measures of non-Markovianity with clear operational interpretations, such as the size of the memory required to simulate a process or the experimental falsifiability of a Markovian hypothesis.

Replacement policy in a system under shocks following a Markovian arrival process

International Nuclear Information System (INIS)

Montoro-Cazorla, Delia; Perez-Ocon, Rafael; Carmen Segovia, Maria del

2009-01-01

We present a system subject to shocks that arrive following a Markovian arrival process. The system is minimally repaired. It is replaced when a certain number of shocks arrive. A general model where the replacements are governed by a discrete phase-type distribution is studied. For this system, the Markov process governing the system is constructed, and the interarrival times between replacements and the number of replacements are calculated. A special case of this system is when it can stand a prefixed number of shocks. For this new system, the same performance measures are calculated. The systems are considered in transient and stationary regime

Replacement policy in a system under shocks following a Markovian arrival process

Energy Technology Data Exchange (ETDEWEB)

Montoro-Cazorla, Delia [Department of Statistics and Operational Research, University of Jaen (Spain); Perez-Ocon, Rafael [Department of Statistics and Operational Research, University of Granada, Granada (Spain)], E-mail: rperezo@ugr.es; Carmen Segovia, Maria del [Departamento de Estadistica e I.O., University of Granada, Granada (Spain)

2009-02-15

We present a system subject to shocks that arrive following a Markovian arrival process. The system is minimally repaired. It is replaced when a certain number of shocks arrive. A general model where the replacements are governed by a discrete phase-type distribution is studied. For this system, the Markov process governing the system is constructed, and the interarrival times between replacements and the number of replacements are calculated. A special case of this system is when it can stand a prefixed number of shocks. For this new system, the same performance measures are calculated. The systems are considered in transient and stationary regime.

Non-Markovian reduced dynamics based upon a hierarchical effective-mode representation

Energy Technology Data Exchange (ETDEWEB)

Burghardt, Irene [Institute of Physical and Theoretical Chemistry, Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438 Frankfurt (Germany); Martinazzo, Rocco [Dipartimento di Chimica, Universita degli Studi di Milano, v. Golgi 19, 20133 Milano (Italy); Hughes, Keith H. [School of Chemistry, Bangor University, Bangor, Gwynedd LL57 2UW (United Kingdom)

2012-10-14

A reduced dynamics representation is introduced which is tailored to a hierarchical, Mori-chain type representation of a bath of harmonic oscillators which are linearly coupled to a subsystem. We consider a spin-boson system where a single effective mode is constructed so as to absorb all system-environment interactions, while the residual bath modes are coupled bilinearly to the primary mode and among each other. Using a cumulant expansion of the memory kernel, correlation functions for the primary mode are obtained, which can be suitably approximated by truncated chains representing the primary-residual mode interactions. A series of reduced-dimensional bath correlation functions is thus obtained, which can be expressed as Fourier-Laplace transforms of spectral densities that are given in truncated continued-fraction form. For a master equation which is second order in the system-bath coupling, the memory kernel is re-expressed in terms of local-in-time equations involving auxiliary densities and auxiliary operators.

Stochastic Stability for Time-Delay Markovian Jump Systems with Sector-Bounded Nonlinearities and More General Transition Probabilities

Directory of Open Access Journals (Sweden)

Dan Ye

2013-01-01

Full Text Available This paper is concerned with delay-dependent stochastic stability for time-delay Markovian jump systems (MJSs with sector-bounded nonlinearities and more general transition probabilities. Different from the previous results where the transition probability matrix is completely known, a more general transition probability matrix is considered which includes completely known elements, boundary known elements, and completely unknown ones. In order to get less conservative criterion, the state and transition probability information is used as much as possible to construct the Lyapunov-Krasovskii functional and deal with stability analysis. The delay-dependent sufficient conditions are derived in terms of linear matrix inequalities to guarantee the stability of systems. Finally, numerical examples are exploited to demonstrate the effectiveness of the proposed method.

Control quantum evolution speed of a single dephasing qubit for arbitrary initial states via periodic dynamical decoupling pulses.

Science.gov (United States)

Song, Ya-Ju; Tan, Qing-Shou; Kuang, Le-Man

2017-03-08

We investigate the possibility to control quantum evolution speed of a single dephasing qubit for arbitrary initial states by the use of periodic dynamical decoupling (PDD) pulses. It is indicated that the quantum speed limit time (QSLT) is determined by initial and final quantum coherence of the qubit, as well as the non-Markovianity of the system under consideration during the evolution when the qubit is subjected to a zero-temperature Ohmic-like dephasing reservoir. It is shown that final quantum coherence of the qubit and the non-Markovianity of the system can be modulated by PDD pulses. Our results show that for arbitrary initial states of the dephasing qubit with non-vanishing quantum coherence, PDD pulses can be used to induce potential acceleration of the quantum evolution in the short-time regime, while PDD pulses can lead to potential speedup and slow down in the long-time regime. We demonstrate that the effect of PDD on the QSLT for the Ohmic or sub-Ohmic spectrum (Markovian reservoir) is much different from that for the super-Ohmic spectrum (non-Markovian reservoir).

SIMULTANEOUS MULTI-BAND DETECTION OF LOW SURFACE BRIGHTNESS GALAXIES WITH MARKOVIAN MODELING

Energy Technology Data Exchange (ETDEWEB)

Vollmer, B.; Bonnarel, F.; Louys, M. [CDS, Observatoire Astronomique, UMR 7550, 11 rue de l' universite, F-67000 Strasbourg (France); Perret, B.; Petremand, M.; Lavigne, F.; Collet, Ch. [LSIIT, Universite de Strasbourg, 7, Rue Rene Descartes, F-67084 Strasbourg (France); Van Driel, W. [GEPI, Observatoire de Paris, CNRS, Universite Paris Diderot, 5 place Jules Janssen, F-92190 Meudon (France); Sabatini, S. [INAF/IASF-Roma, via Fosso de Cavaliere 100, I-00133 Roma (Italy); MacArthur, L. A., E-mail: Bernd.Vollmer@astro.unistra.fr [Herzberg Institute of Astrophysics, National Research Council of Canada, Victoria, BC V9E 2E7 (Canada)

2013-02-01

We present to the astronomical community an algorithm for the detection of low surface brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings-typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. The application of the method to two and three bands simultaneously was tested on simulated images. Based on our tests, we are confident that we can detect LSB galaxies down to a central surface brightness level of only 1.5 times the standard deviation from the mean pixel value in the image background. To assess the robustness of our method, the method was applied to a set of 18 B- and I-band images (covering 1.3 deg{sup 2} in total) of the Virgo Cluster to which Sabatini et al. previously applied a matched-filter dwarf LSB galaxy search algorithm. We have detected all 20 objects from the Sabatini et al. catalog which we could classify by eye as bona fide LSB galaxies. Our method has also detected four additional Virgo Cluster LSB galaxy candidates undetected by Sabatini et al. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (1) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (2) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered {approx}20% more mock LSB galaxies and {approx}40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of

Stochastic quantization of a topological quantum mechanical model

International Nuclear Information System (INIS)

Antunes, Sergio; Krein, Gastao; Menezes, Gabriel; Svaiter, Nami Fux

2011-01-01

Full text: Stochastic quantization of complex actions has been extensively studied in the literature. In these models, a Markovian Langevin equation is used in order to study the quantization of such systems. In such papers, the advantages of the Markovian stochastic quantization method were explored and exposed. However, many drawbacks of the method were also pointed out, such as instability of the simulations with absence of convergence and sometimes convergence to the wrong limit. Indeed, although several alternative methods have been proposed to deal with interesting physical systems where the action is complex, these approaches do not suggest any general way of solving the particular difficulties that arise in each situation. Here, we wish to make contributions to the program of stochastic quantization of theories with imaginary action by investigating the consequences of a non-Markovian stochastic quantization in a particular situation, namely a quantum mechanical topological action. We analyze the Markovian stochastic quantization for a topological quantum mechanical action which is analog to a Maxwell-Chern-Simons action in the Weyl gauge. Afterwards we consider a Langevin equation with memory kernel and Einstein's relations with colored noise. We show that convergence towards equilibrium is achieved in both regimes. We also sketch a simple numerical analysis to investigate the possible advantages of non-Markovian procedure over the usual Markovian quantization. Both retarded Green's function for the diffusion problem are considered in such analysis. We show that, although the results indicated that the effect of memory kernel, as usually expected, is to delay the convergence to equilibrium, non-Markovian systems imply a faster decay compared to Markovian ones as well as smoother convergence to equilibrium. (author)

Non-Markovian dynamics of entanglement for multipartite systems

Energy Technology Data Exchange (ETDEWEB)

Zhou Jiang; Wu Chengjun; Zhu Mingyi; Guo Hong, E-mail: hongguo@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, and Center for Computational Science and Engineering (CCSE), Peking University, Beijing 100871 (China)

2009-11-14

Entanglement dynamics for a couple of two-level atoms interacting with independent structured reservoirs is studied using a non-perturbative approach. It is shown that the revival of atom entanglement is not necessarily accompanied by the sudden death of reservoir entanglement, and vice versa. In fact, atom entanglement can revive before, simultaneously or even after the disentanglement of reservoirs. Using a novel method based on the population analysis for the excited atomic state, we present the quantitative criteria for the revival and death phenomena. To give a more physically intuitive insight, the quasimode Hamiltonian method is applied. Our quantitative analysis is helpful for the practical engineering of entanglement.

Collapse–revival of squeezing of two atoms in dissipative cavities

International Nuclear Information System (INIS)

Zou Hong-Mei; Fang Mao-Fa

2016-01-01

Based on the time-convolutionless master-equation approach, we investigate the squeezing dynamics of two atoms in dissipative cavities. We find that the atomic squeezing is related to initial atomic states, atom–cavity couplings, non-Markovian effects and resonant frequencies of an atom and its cavity. The results show that a collapse–revival phenomenon will occur in the atomic squeezing and this process is accompanied by the buildup and decay of entanglement between two atoms. Enhancing the atom–cavity coupling can increase the frequency of the collapse–revival of the atomic squeezing. The stronger the non-Markovian effect is, the more obvious the collapse–revival phenomenon is. In particular, if the atom–cavity coupling or the non-Markovian effect is very strong, the atomic squeezing will tend to a stably periodic oscillation in a long time. The oscillatory frequency of the atomic squeezing is dependent on the resonant frequency of the atom and its cavity. (paper)

Oral manifestations of anemia in HIV/AIDS patients without ARV treatment

Directory of Open Access Journals (Sweden)

Wahyu Hidayat

2017-03-01

Full Text Available Abstract Introduction: Acquired immunodeficiency syndrome (AIDS is  a set of symptoms caused by decreases of the immune system that was infected by human immunodeficiency virus (HIV. Blood disorders often found in patient with HIV and associated with HIV infection. Mostly found disorders is anemia of chronic disease. The prevalence of anemia in HIV/AIDS patients reaches 70%. Oral manifestations of anemia are atrophy of the papillae on tongue, glossodynia, pallor, angular cheilitis, glossitis, aphthous ulcers/erosive lesions, candidiasis, and geographic tongue. There are many publications that uses anemia as indicator to determine the prognosis of HIV infection, thus the description of oral manifestation of anemia in the non-ARV HIV/AIDS patients is a necessity. The purpose of this study was to describe the oral manifestation of anemia in the non-ARV HIV/AIDS patients. Methods: The methods used were purposive random sampling. Samples were new HIV/AIDS patients who have not got antiretroviral (ARV treatment. The study included 40 patients in Teratai Clinic Hasan Sadikin Hospital Bandung. Results: Oral manifestations of anemia were found amongst non-ARV HIV/AIDS patients, which were candidiasis in  37 patients, glossodynia in 28 patients, glossitis in 10 patients, and angular cheilitis in 1 patient. Conclusion: From the study found that oral manifestations of anemia that found in non-ARV HIV/AIDS patients were candidiasis, glossodynia, glossitis and angular cheilitis. HIV/AIDS patients with anemia needed to treat more intensive for better prognosis and quality of life. Keywords: Anemia, HIV/AIDS, Candidiasis, Glossitis, Glossodynia

Influence of Superconducting Leads Energy Gap on Electron Transport Through Double Quantum Dot by Markovian Quantum Master Equation Approach

International Nuclear Information System (INIS)

Afsaneh, E.; Yavari, H.

2014-01-01

The superconducting reservoir effect on the current carrying transport of a double quantum dot in Markovian regime is investigated. For this purpose, a quantum master equation at finite temperature is derived for the many-body density matrix of an open quantum system. The dynamics and the steady-state properties of the double quantum dot system for arbitrary bias are studied. We will show that how the populations and coherencies of the system states are affected by superconducting leads. The energy parameter of system contains essentially four contributions due to dots system-electrodes coupling, intra dot coupling, two quantum dots inter coupling and superconducting gap. The coupling effect of each energy contribution is applied to currents and coherencies results. In addition, the effect of energy gap is studied by considering the amplitude and lifetime of coherencies to get more current through the system. (author)

A single-server Markovian queuing system with discouraged arrivals and retention of reneged customers

Directory of Open Access Journals (Sweden)

Kumar Rakesh

2014-01-01

Full Text Available Customer impatience has a very negative impact on the queuing system under investigation. If we talk from business point of view, the firms lose their potential customers due to customer impatience, which affects their business as a whole. If the firms employ certain customer retention strategies, then there are chances that a certain fraction of impatient customers can be retained in the queuing system. A reneged customer may be convinced to stay in the queuing system for his further service with some probability, say q and he may abandon the queue without receiving the service with a probability p(=1− q. A finite waiting space Markovian single-server queuing model with discouraged arrivals, reneging and retention of reneged customers is studied. The steady state solution of the model is derived iteratively. The measures of effectiveness of the queuing model are also obtained. Some important queuing models are derived as special cases of this model.

Quantum theory of multiple-input-multiple-output Markovian feedback with diffusive measurements

International Nuclear Information System (INIS)

Chia, A.; Wiseman, H. M.

2011-01-01

Feedback control engineers have been interested in multiple-input-multiple-output (MIMO) extensions of single-input-single-output (SISO) results of various kinds due to its rich mathematical structure and practical applications. An outstanding problem in quantum feedback control is the extension of the SISO theory of Markovian feedback by Wiseman and Milburn [Phys. Rev. Lett. 70, 548 (1993)] to multiple inputs and multiple outputs. Here we generalize the SISO homodyne-mediated feedback theory to allow for multiple inputs, multiple outputs, and arbitrary diffusive quantum measurements. We thus obtain a MIMO framework which resembles the SISO theory and whose additional mathematical structure is highlighted by the extensive use of vector-operator algebra.

Evidence of Non-local Chemical, Thermal and Gravitational Effects

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Hu H.

2007-04-01

Full Text Available Quantum entanglement is ubiquitous in the microscopic world and manifests itself macroscopically under some circumstances. But common belief is that it alone cannot be used to transmit information nor could it be used to produce macroscopic non- local effects. Yet we have recently found evidence of non-local effects of chemical substances on the brain produced through it. While our reported results are under independent verifications by other groups, we report here our experimental findings of non-local chemical, thermal and gravitational effects in simple physical systems such as reservoirs of water quantum-entangled with water being manipulated in a remote reservoir. With the aids of high-precision instruments, we have found that the pH value, temperature and gravity of water in the detecting reservoirs can be non-locally affected through manipulating water in the remote reservoir. In particular, the pH value changes in the same direction as that being manipulated; the temperature can change against that of local environment; and the gravity apparently can also change against local gravity. These non-local effects are all reproducible and can be used for non-local signalling and many other purposes. We suggest that they are mediated by quantum entanglement between nuclear and/or electron spins in treated water and discuss the implications of these results.

Coherencia y entrelazamiento en dinámica no Markoviana de qubits

Directory of Open Access Journals (Sweden)

Cristian Edwin Susa Quintero

2013-06-01

Full Text Available We provide a thorough analysis of the entanglement dynamics of an interacting two-qubit systemin the non-Markovian regime. In such a regime, the time scale on which the reservoir degrees offreedom evolve is either of the same order of magnitude or less than that on which the systemevolves.We used an exact numerical method; the Quasi-Adiabatic Path Integral (QUAPI technique,to describe the corresponding qubit dissipative dynamics in such a non-Markovian regime. Wecomputed the time evolution of the density operator for the quibits, from which we quantified thecoherences and population dynamics, as well as the qubit-bath coupling effects. Using negativityas a metric, we calculated the dynamics of non-local quantum correlations (entanglement, andindentified a non-Markovian quantum phenomena in terms of early stage disentanglement, and thecollapse and revival of entanglement.

Analytic Approximation of the Solutions of Stochastic Differential Delay Equations with Poisson Jump and Markovian Switching

Directory of Open Access Journals (Sweden)

Hua Yang

2012-01-01

Full Text Available We are concerned with the stochastic differential delay equations with Poisson jump and Markovian switching (SDDEsPJMSs. Most SDDEsPJMSs cannot be solved explicitly as stochastic differential equations. Therefore, numerical solutions have become an important issue in the study of SDDEsPJMSs. The key contribution of this paper is to investigate the strong convergence between the true solutions and the numerical solutions to SDDEsPJMSs when the drift and diffusion coefficients are Taylor approximations.

Immunologic manifestations of autophagy

DEFF Research Database (Denmark)

Deretic, Vojo; Kimura, Tomonori; Timmins, Graham

2015-01-01

The broad immunologic roles of autophagy span innate and adaptive immunity and are often manifested in inflammatory diseases. The immune effects of autophagy partially overlap with its roles in metabolism and cytoplasmic quality control but typically expand further afield to encompass unique...... immunologic adaptations. One of the best-appreciated manifestations of autophagy is protection against microbial invasion, but this is by no means limited to direct elimination of intracellular pathogens and includes a stratified array of nearly all principal immunologic processes. This Review summarizes...... the broad immunologic roles of autophagy. Furthermore, it uses the autophagic control of Mycobacterium tuberculosis as a paradigm to illustrate the breadth and complexity of the immune effects of autophagy....

New Passivity Criteria for Fuzzy Bam Neural Networks with Markovian Jumping Parameters and Time-Varying Delays

Science.gov (United States)

Vadivel, P.; Sakthivel, R.; Mathiyalagan, K.; Thangaraj, P.

2013-02-01

This paper addresses the problem of passivity analysis issue for a class of fuzzy bidirectional associative memory (BAM) neural networks with Markovian jumping parameters and time varying delays. A set of sufficient conditions for the passiveness of the considered fuzzy BAM neural network model is derived in terms of linear matrix inequalities by using the delay fractioning technique together with the Lyapunov function approach. In addition, the uncertainties are inevitable in neural networks because of the existence of modeling errors and external disturbance. Further, this result is extended to study the robust passivity criteria for uncertain fuzzy BAM neural networks with time varying delays and uncertainties. These criteria are expressed in the form of linear matrix inequalities (LMIs), which can be efficiently solved via standard numerical software. Two numerical examples are provided to demonstrate the effectiveness of the obtained results.

Manifestation of Aerosol Indirect Effects in Arctic Clouds

Science.gov (United States)

Lubin, D.; Vogelmann, A. M.

2009-12-01

The first aerosol indirect effect has traditionally been conceived as an enhancement of shortwave cloud reflectance in response to decreased effective droplet size at fixed liquid water path, as cloud nucleating aerosol becomes entrained in the cloud. The high Arctic, with its pervasive low-level stratiform cloud cover and frequent episodes of anthropogenic aerosol (Artic "haze"), has in recent years served as a natural laboratory for research on actual manifestations of aerosol indirect effects. This paper will review the surprising set of developments: (1) the detection of the indirect effect as a source of surface warming, rather than cooling, throughout early spring, (2) a transition to a cooling effect in late spring, corresponding to the beginning of the sea ice melt season, and (3) detection of an indirect effect during summer, outside of the "Arctic haze" season. This paper will also discuss measurements of spectral shortwave irradiance (350-2200 nm) made at Barrow, Alaska, during the U.S. Department of Energy's Indirect and Semi-Direct Aerosol Campaign (ISDAC), which reveal complications in our conception of the indirect effect related to the ice phase in Arctic stratiform clouds.

Fluctuation relation for heat exchange in Markovian open quantum systems

Science.gov (United States)

Ramezani, M.; Golshani, M.; Rezakhani, A. T.

2018-04-01

A fluctuation relation for the heat exchange of an open quantum system under a thermalizing Markovian dynamics is derived. We show that the probability that the system absorbs an amount of heat from its bath, at a given time interval, divided by the probability of the reverse process (releasing the same amount of heat to the bath) is given by an exponential factor which depends on the amount of heat and the difference between the temperatures of the system and the bath. Interestingly, this relation is akin to the standard form of the fluctuation relation (for forward-backward dynamics). We also argue that the probability of the violation of the second law of thermodynamics in the form of the Clausius statement (i.e., net heat transfer from a cold system to its hot bath) drops exponentially with both the amount of heat and the temperature differences of the baths.

Orofacial manifestations of hematological disorders: Anemia and hemostatic disorders

Directory of Open Access Journals (Sweden)

Titilope A Adeyemo

2011-01-01

Full Text Available The aim of this paper is to review the literature and identify orofacial manifestations of hematological diseases, with particular reference to anemias and disorders of hemostasis. A computerized literature search using MEDLINE was conducted for published articles on orofacial manifestations of hematological diseases, with emphasis on anemia. Mesh phrases used in the search were: oral diseases AND anaemia; orofacial diseases AND anaemia; orofacial lesions AND anaemia; orofacial manifestations AND disorders of haemostasis. The Boolean operator "AND" was used to combine and narrow the searches. Anemic disorders associated with orofacial signs and symptoms include iron deficiency anemia, Plummer-Vinson syndrome, megaloblastic anemia, sickle cell anemia, thalassaemia and aplastic anemia. The manifestations include conjunctiva and facial pallor, atrophic glossitis, angular stomatitis, dysphagia, magenta tongue, midfacial overgrowth, osteoclerosis, osteomyelitis and paraesthesia/anesthesia of the mental nerve. Orofacial petechiae, conjunctivae hemorrhage, nose-bleeding, spontaneous and post-traumatic gingival hemorrhage and prolonged post-extraction bleeding are common orofacial manifestations of inherited hemostatic disorders such as von Willebrand′s disease and hemophilia. A wide array of anemic and hemostatic disorders encountered in internal medicine has manifestations in the oral cavity and the facial region. Most of these manifestations are non-specific, but should alert the hematologist and the dental surgeon to the possibilities of a concurrent disease of hemopoiesis or hemostasis or a latent one that may subsequently manifest itself.

The Casimir effect physical manifestations of zero-point energy

CERN Document Server

Milton, K A

2001-01-01

In its simplest manifestation, the Casimir effect is a quantum force of attraction between two parallel uncharged conducting plates. More generally, it refers to the interaction - which may be either attractive or repulsive - between material bodies due to quantum fluctuations in whatever fields are relevant. It is a local version of the van der Waals force between molecules. Its sweep ranges from perhaps its being the origin of the cosmological constant to its being responsible for the confinement of quarks. This monograph develops the theory of such forces, based primarily on physically tran

Prevalence of latent and manifest hyperthyroidism in an iodine-deficient area: non-selected patient population admitted for CT studies with iodine-containing contrast agents

International Nuclear Information System (INIS)

Saam, T.; Hess, T.; Kasperk, C.; Kauffmann, G.W.; Duex, M.

2005-01-01

Purpose: to evaluate the prevalence of latent and manifest hyperthyroidism in a non-selected group of patients admitted for contrast enhanced CT studies blood samples were tested for the levels of thyroid-stimulating hormone (TSH). Material and methods: TSH blood levels were obtained in 548 consecutive patients who were scheduled for contrast-enhanced (Iopromide; 300 mg iodine/ml) CT scanning. In case of TSH levels registered (sodium perchlorate) was commenced before scanning. In case of TSH levels < 0.1 mU/l, CT scanning was not performed but further evaluation of the thyroid function was initiated. Results: TSH blood levels ranged from 0.4 to 7.5 mU/l in 512 patients, and 36 patients (6.6%) had TSH blood levels < 0.4 mU/l and 9 patients blood levels < 0.1 mU/l, with 32 of those patients (5.8%) having regular T3 and T4 blood levels consistent with latent hyperthyroidism. In 4 patients (0.8%), T3 or T4 blood levels were increased consistent with manifest hyperthyroidism. Conclusion: in South Germany, the prevalence of latent or manifest hyperthyroidism in a non-selected patient group is high. Therefore TSH blood levels should be obtained prior to contrast-enhanced CT studies. (orig.)

Ultrasound manifestation of hepatocellular carcinoma

International Nuclear Information System (INIS)

Hwang, M. S.; Yoo, H. S.; Park, C. Y.; Choi, H. J.; Moon, Y. M.; Lee, S. I.

1982-01-01

With the advent of gray scale ultrasonographic equipment, the parenchymal disease of liver is more easily evaluated. Ultrasonography is a non-invasive technique, different from angiography, and performed without discomfort to patient. And also ultrasonography can be used in assessing the liver in cases showing equivocal scintigraphy and in differentiation of solid and cystic masses, first detected on scintigrams. Therefore, the complementary use of ultrasonography, Tc-99m-sulfur colloid scan and angiography provides better diagnostic accuracy for the detection of hepatocellular carcinoma, and moreover, sequential ultrasonographic studies in the same patient are valuable of following the course of hepatocellular carcinoma and monitoring the effectiveness of therapy for hepatocellular carcinoma. In thirty patients with histologically proven hepatocellular carcinoma, an analysis of ultrasound manifestation is made and the results are as follows; 1. Ultrasound manifestation of hepatocellular carcinoma by gray scale showed four different sonographic patterns including discrete echo free, discrete echogenic, ill defined echogenic and mixed patterns. 2. The size of hepatocellular carcinoma by ultrasonographic measurement was larger than 5 cm in diameter in 28 cases. 3. In 7 cases performed with angiography, all echogenicities of hepatocellualr carcinoma were correlated with the findings of vascularity of angiography. 4. In cases combined with liver cirrhosis, the sonographic pattern of hepatocellular carcinoma appeared to be discrete or ill defined echogenic patterns

Ultrasound manifestation of hepatocellular carcinoma

Energy Technology Data Exchange (ETDEWEB)

Hwang, M S; Yoo, H S; Park, C Y; Choi, H J; Moon, Y M; Lee, S I [Yonsei University College of Medicine, Seoul (Korea, Republic of)

1982-06-15

With the advent of gray scale ultrasonographic equipment, the parenchymal disease of liver is more easily evaluated. Ultrasonography is a non-invasive technique, different from angiography, and performed without discomfort to patient. And also ultrasonography can be used in assessing the liver in cases showing equivocal scintigraphy and in differentiation of solid and cystic masses, first detected on scintigrams. Therefore, the complementary use of ultrasonography, Tc-99m-sulfur colloid scan and angiography provides better diagnostic accuracy for the detection of hepatocellular carcinoma, and moreover, sequential ultrasonographic studies in the same patient are valuable of following the course of hepatocellular carcinoma and monitoring the effectiveness of therapy for hepatocellular carcinoma. In thirty patients with histologically proven hepatocellular carcinoma, an analysis of ultrasound manifestation is made and the results are as follows; 1. Ultrasound manifestation of hepatocellular carcinoma by gray scale showed four different sonographic patterns including discrete echo free, discrete echogenic, ill defined echogenic and mixed patterns. 2. The size of hepatocellular carcinoma by ultrasonographic measurement was larger than 5 cm in diameter in 28 cases. 3. In 7 cases performed with angiography, all echogenicities of hepatocellualr carcinoma were correlated with the findings of vascularity of angiography. 4. In cases combined with liver cirrhosis, the sonographic pattern of hepatocellular carcinoma appeared to be discrete or ill defined echogenic patterns.

Clinical manifestations of scrub typhus.

Science.gov (United States)

Rajapakse, Senaka; Weeratunga, Praveen; Sivayoganathan, Sriharan; Fernando, Sumadhya Deepika

2017-02-01

The mite-borne rickettsial zoonosis scrub typhus is widely prevalent in parts of Southeast and Far East Asia, and northern Australia. The disease is an acute febrile illness, associated with rash and often an eschar, which responds dramatically to treatment with antibiotics. In some cases it results in a serious illness leading to multiple organ involvement and death. The disease manifestations are thought to result from a systemic vasculitis, caused by both direct effects of the organisms as well as an exaggerated immune response, although little is understood about its pathogenesis. A wide spectrum of clinical manifestations, affecting nearly every organ system, have been described with scrub typhus. Some of these manifestations are serious and life threatening. In this systematic review, we summarise the typical and atypical manifestations of scrub typhus reported in the literature. Awareness of these unusual manifestations will hopefully guide clinicians towards diagnosing the condition early, and initiating early appropriate antibiotics and other supportive measures. © The Author 2017. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Impact and frequency of extra-genitourinary manifestations of prune belly syndrome.

Science.gov (United States)

Grimsby, G M; Harrison, S M; Granberg, C F; Bernstein, I H; Baker, L A

2015-10-01

Prune belly syndrome (PBS) extra-genitourinary (extra-GU) manifestations are serious comorbidities beyond the genitourinary (GU) anomalies of this disease. We hypothesized an underestimation of the reported frequency and understated impact on quality of life (QOL) of extra-GU comorbidities in PBS survivors beyond the newborn period. To assess this, the frequencies of extra-GU manifestations of PBS in a contemporary cohort of living patients were compared to compiled frequencies from published literature. Second, the impact of extra-GU PBS manifestations on patient/family QOL was assessed via a non-validated open-ended survey. From 2010 to 2013, PBS survivors were prospectively recruited locally or at three PBS Network National Conventions. The family/subject was asked to complete a detailed PBS questionnaire, non-validated QOL survey, and provide medical records for review. Clinical data were extracted from medical records for local patients. The frequencies of extra-GU manifestations were compared between the contemporary, living cohort and a published literature cohort derived from PubMed. Seven of 706 published studies met criteria for frequencies tabulation of extra-GU PBS manifestations. This largest reported living PBS patient cohort (n = 65) was 99% male with mean age 10 years (1 month-45 years). The living PBS cohort had a statistically significantly higher incidence of gastrointestinal (63%), orthopedic (65%), and cardiopulmonary (49%) diagnoses compared to the compiled published cohort (n = 204). Eleven PBS males and 32 family members completed the QOL survey. Of these, 47% listed at least one non-GU problem (i.e. lung disease, skeletal problems, constipation) as negatively affecting their QOL; 42% listed at least one GU problem (i.e. self-catheterization, recurrent UTIs) as negatively affecting their QOL; 56% reported musculoskeletal surgery and 21% reported gastrointestinal surgery/medication as positively impacting their QOL. In this large contemporary

Correlation effects in a discrete quantum random walk

International Nuclear Information System (INIS)

Stang, J B; Rezakhani, A T; Sanders, B C

2009-01-01

We introduce memory-dependent discrete-time quantum random walk models by adding uncorrelated memory terms and also by modifying the Hamiltonian of the walker to include couplings with memory-keeping agents. We next study numerically the correlation effects in these models. We also propose a correlation exponent as a relevant and promising tool for investigation of correlation or memory (hence non-Markovian) effects. Our analysis can easily be applied to more realistic models in which different regimes may emerge because of competition between different underlying physical mechanisms

Markovian robots: Minimal navigation strategies for active particles

Science.gov (United States)

Nava, Luis Gómez; Großmann, Robert; Peruani, Fernando

2018-04-01

We explore minimal navigation strategies for active particles in complex, dynamical, external fields, introducing a class of autonomous, self-propelled particles which we call Markovian robots (MR). These machines are equipped with a navigation control system (NCS) that triggers random changes in the direction of self-propulsion of the robots. The internal state of the NCS is described by a Boolean variable that adopts two values. The temporal dynamics of this Boolean variable is dictated by a closed Markov chain—ensuring the absence of fixed points in the dynamics—with transition rates that may depend exclusively on the instantaneous, local value of the external field. Importantly, the NCS does not store past measurements of this value in continuous, internal variables. We show that despite the strong constraints, it is possible to conceive closed Markov chain motifs that lead to nontrivial motility behaviors of the MR in one, two, and three dimensions. By analytically reducing the complexity of the NCS dynamics, we obtain an effective description of the long-time motility behavior of the MR that allows us to identify the minimum requirements in the design of NCS motifs and transition rates to perform complex navigation tasks such as adaptive gradient following, detection of minima or maxima, or selection of a desired value in a dynamical, external field. We put these ideas in practice by assembling a robot that operates by the proposed minimalistic NCS to evaluate the robustness of MR, providing a proof of concept that is possible to navigate through complex information landscapes with such a simple NCS whose internal state can be stored in one bit. These ideas may prove useful for the engineering of miniaturized robots.

Reliability importance analysis of Markovian systems at steady state using perturbation analysis

Energy Technology Data Exchange (ETDEWEB)

Phuc Do Van [Institut Charles Delaunay - FRE CNRS 2848, Systems Modeling and Dependability Group, Universite de technologie de Troyes, 12, rue Marie Curie, BP 2060-10010 Troyes cedex (France); Barros, Anne [Institut Charles Delaunay - FRE CNRS 2848, Systems Modeling and Dependability Group, Universite de technologie de Troyes, 12, rue Marie Curie, BP 2060-10010 Troyes cedex (France)], E-mail: anne.barros@utt.fr; Berenguer, Christophe [Institut Charles Delaunay - FRE CNRS 2848, Systems Modeling and Dependability Group, Universite de technologie de Troyes, 12, rue Marie Curie, BP 2060-10010 Troyes cedex (France)

2008-11-15

Sensitivity analysis has been primarily defined for static systems, i.e. systems described by combinatorial reliability models (fault or event trees). Several structural and probabilistic measures have been proposed to assess the components importance. For dynamic systems including inter-component and functional dependencies (cold spare, shared load, shared resources, etc.), and described by Markov models or, more generally, by discrete events dynamic systems models, the problem of sensitivity analysis remains widely open. In this paper, the perturbation method is used to estimate an importance factor, called multi-directional sensitivity measure, in the framework of Markovian systems. Some numerical examples are introduced to show why this method offers a promising tool for steady-state sensitivity analysis of Markov processes in reliability studies.

Reliability importance analysis of Markovian systems at steady state using perturbation analysis

International Nuclear Information System (INIS)

Phuc Do Van; Barros, Anne; Berenguer, Christophe

2008-01-01

Sensitivity analysis has been primarily defined for static systems, i.e. systems described by combinatorial reliability models (fault or event trees). Several structural and probabilistic measures have been proposed to assess the components importance. For dynamic systems including inter-component and functional dependencies (cold spare, shared load, shared resources, etc.), and described by Markov models or, more generally, by discrete events dynamic systems models, the problem of sensitivity analysis remains widely open. In this paper, the perturbation method is used to estimate an importance factor, called multi-directional sensitivity measure, in the framework of Markovian systems. Some numerical examples are introduced to show why this method offers a promising tool for steady-state sensitivity analysis of Markov processes in reliability studies

Optimal Investment-Consumption Strategy under Inflation in a Markovian Regime-Switching Market

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Huiling Wu

2016-01-01

Full Text Available This paper studies an investment-consumption problem under inflation. The consumption price level, the prices of the available assets, and the coefficient of the power utility are assumed to be sensitive to the states of underlying economy modulated by a continuous-time Markovian chain. The definition of admissible strategies and the verification theory corresponding to this stochastic control problem are presented. The analytical expression of the optimal investment strategy is derived. The existence, boundedness, and feasibility of the optimal consumption are proven. Finally, we analyze in detail by mathematical and numerical analysis how the risk aversion, the correlation coefficient between the inflation and the stock price, the inflation parameters, and the coefficient of utility affect the optimal investment and consumption strategy.

Study of open systems with molecules in isotropic liquids

Science.gov (United States)

Kondo, Yasushi; Matsuzaki, Masayuki

2018-05-01

We are interested in dynamics of a system in an environment, or an open system. Such phenomena as crossover from Markovian to non-Markovian relaxation and thermal equilibration are of our interest. Open systems have experimentally been studied with ultra cold atoms, ions in traps, optics, and cold electric circuits because well-isolated systems can be prepared here and thus the effects of environments can be controlled. We point out that some molecules solved in isotropic liquid are well isolated and thus they can also be employed for studying open systems in Nuclear Magnetic Resonance (NMR) experiments. First, we provide a short review on related phenomena of open systems that helps readers to understand our motivation. We, then, present two experiments as examples of our approach with molecules in isotropic liquids. Crossover from Markovian to non-Markovian relaxation was realized in one NMR experiment, while relaxation-like phenomena were observed in approximately isolated systems in the other.

Sample efficient multiagent learning in the presence of Markovian agents

CERN Document Server

Chakraborty, Doran

2014-01-01

The problem of Multiagent Learning (or MAL) is concerned with the study of how intelligent entities can learn and adapt in the presence of other such entities that are simultaneously adapting. The problem is often studied in the stylized settings provided by repeated matrix games (a.k.a. normal form games). The goal of this book is to develop MAL algorithms for such a setting that achieve a new set of objectives which have not been previously achieved. In particular this book deals with learning in the presence of a new class of agent behavior that has not been studied or modeled before in a MAL context: Markovian agent behavior. Several new challenges arise when interacting with this particular class of agents. The book takes a series of steps towards building completely autonomous learning algorithms that maximize utility while interacting with such agents. Each algorithm is meticulously specified with a thorough formal treatment that elucidates its key theoretical properties.

Two parallel finite queues with simultaneous services and Markovian arrivals

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S. R. Chakravarthy

1997-01-01

Full Text Available In this paper, we consider a finite capacity single server queueing model with two buffers, A and B, of sizes K and N respectively. Messages arrive one at a time according to a Markovian arrival process. Messages that arrive at buffer A are of a different type from the messages that arrive at buffer B. Messages are processed according to the following rules: 1. When buffer A(B has a message and buffer B(A is empty, then one message from A(B is processed by the server. 2. When both buffers, A and B, have messages, then two messages, one from A and one from B, are processed simultaneously by the server. The service times are assumed to be exponentially distributed with parameters that may depend on the type of service. This queueing model is studied as a Markov process with a large state space and efficient algorithmic procedures for computing various system performance measures are given. Some numerical examples are discussed.

e-Manifest

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This is the primary hub for those seeking information about the e-Manifest system, its advisory board, and its development. Once the system is complete this area will serve as the portal into the e-Manifest system from EPA webpages.

A comparison between Markovian models and Bayesian networks for treating some dependent events in reliability evaluations

International Nuclear Information System (INIS)

Duarte, Juliana P.; Leite, Victor C.; Melo, P.F. Frutuoso e

2013-01-01

Bayesian networks have become a very handy tool for solving problems in various application areas. This paper discusses the use of Bayesian networks to treat dependent events in reliability engineering typically modeled by Markovian models. Dependent events play an important role as, for example, when treating load-sharing systems, bridge systems, common-cause failures, and switching systems (those for which a standby component is activated after the main one fails by means of a switching mechanism). Repair plays an important role in all these cases (as, for example, the number of repairmen). All Bayesian network calculations are performed by means of the Netica™ software, of Norsys Software Corporation, and Fortran 90 to evaluate them over time. The discussion considers the development of time-dependent reliability figures of merit, which are easily obtained, through Markovian models, but not through Bayesian networks, because these latter need probability figures as input and not failure and repair rates. Bayesian networks produced results in very good agreement with those of Markov models and pivotal decomposition. Static and discrete time (DTBN) Bayesian networks were used in order to check their capabilities of modeling specific situations, like switching failures in cold-standby systems. The DTBN was more flexible to modeling systems where the time of occurrence of an event is important, for example, standby failure and repair. However, the static network model showed as good results as DTBN by a much more simplified approach. (author)

A comparison between Markovian models and Bayesian networks for treating some dependent events in reliability evaluations

Energy Technology Data Exchange (ETDEWEB)

Duarte, Juliana P.; Leite, Victor C.; Melo, P.F. Frutuoso e, E-mail: julianapduarte@poli.ufrj.br, E-mail: victor.coppo.leite@poli.ufrj.br, E-mail: frutuoso@nuclear.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

2013-07-01

Bayesian networks have become a very handy tool for solving problems in various application areas. This paper discusses the use of Bayesian networks to treat dependent events in reliability engineering typically modeled by Markovian models. Dependent events play an important role as, for example, when treating load-sharing systems, bridge systems, common-cause failures, and switching systems (those for which a standby component is activated after the main one fails by means of a switching mechanism). Repair plays an important role in all these cases (as, for example, the number of repairmen). All Bayesian network calculations are performed by means of the Netica™ software, of Norsys Software Corporation, and Fortran 90 to evaluate them over time. The discussion considers the development of time-dependent reliability figures of merit, which are easily obtained, through Markovian models, but not through Bayesian networks, because these latter need probability figures as input and not failure and repair rates. Bayesian networks produced results in very good agreement with those of Markov models and pivotal decomposition. Static and discrete time (DTBN) Bayesian networks were used in order to check their capabilities of modeling specific situations, like switching failures in cold-standby systems. The DTBN was more flexible to modeling systems where the time of occurrence of an event is important, for example, standby failure and repair. However, the static network model showed as good results as DTBN by a much more simplified approach. (author)

Effects of Onchocerciasis Manifestations on Academic Performance ...

African Journals Online (AJOL)

... in order to reduce the parasite reservoir in man, and also breaking the man-fly contact either by use of repellents or through proper covering of the body during outdoor activities. Key Words: Onchocerciasis, manifestation, academic performance, weighted average, visual impairment. Bio-Research Vol.1(2) 2003: 77-85 ...

CT manifestations of liver abscess

International Nuclear Information System (INIS)

Yan Jianfeng; Peng Yongjun

2006-01-01

Objective: To study CT findings of hepatic abscess. Methods: CT findings and clinical materials of 38 patients with liver abscess verified by aspiration were retrospectively viewed. All patients were examined by non-enhanced and contrast enhanced CT. Results: In 25 cases, inhomogeneous hypodense lesions with unclear demarcation were found on non-enhanced CT. On contrast enhanced CT scan, target or cluster enhancement was found Additionally, air was found within some lesions. In the rest 13 cases with early stage liver abscess, no typical sign was found on non-enhanced CT, while rosette sign and continued enhancement sign were demonstrated after the contrast agent was given. Conclusion: Various CT findings are found in different stages of liver abscess. The diagnosis and differential diagnosis should be based on CT manifestations and clinical history as well. (authors)

Stochastic exponential stability of the delayed reaction-diffusion recurrent neural networks with Markovian jumping parameters

International Nuclear Information System (INIS)

Wang Linshan; Zhang Zhe; Wang Yangfan

2008-01-01

Some criteria for the global stochastic exponential stability of the delayed reaction-diffusion recurrent neural networks with Markovian jumping parameters are presented. The jumping parameters considered here are generated from a continuous-time discrete-state homogeneous Markov process, which are governed by a Markov process with discrete and finite state space. By employing a new Lyapunov-Krasovskii functional, a linear matrix inequality (LMI) approach is developed to establish some easy-to-test criteria of global exponential stability in the mean square for the stochastic neural networks. The criteria are computationally efficient, since they are in the forms of some linear matrix inequalities

Non-targeted and delayed effects of exposure to ionizing radiation: II. Radiation-induced genomic instability and bystander effects in vivo, clastogenic factors and transgenerational effects

Science.gov (United States)

Morgan, William F.

2003-01-01

The goal of this review is to summarize the evidence for non-targeted and delayed effects of exposure to ionizing radiation in vivo. Currently, human health risks associated with radiation exposures are based primarily on the assumption that the detrimental effects of radiation occur in irradiated cells. Over the years a number of non-targeted effects of radiation exposure in vivo have been described that challenge this concept. These include radiation-induced genomic instability, bystander effects, clastogenic factors produced in plasma from irradiated individuals that can cause chromosomal damage when cultured with nonirradiated cells, and transgenerational effects of parental irradiation that can manifest in the progeny. These effects pose new challenges to evaluating the risk(s) associated with radiation exposure and understanding radiation-induced carcinogenesis.

EXTRAGASTRIC AND ORODENTAL MANIFESTATIONS IN PEDIATRIC INFECTION WITH HELICOBACTER PYLORI. A REVIEW

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Smaranda DIACONESCU

2015-12-01

Full Text Available Helicobacter pylori is a worlwide spread infection mostly manifested in childhood. Many - both invasive and non-invasive diagnostic tests - are now available,. The colonisation effect of gastric mucosa and its consequences are well known and studied. H. pylori can also induce extra-gastric manifestations, like iron-deficiency anemia. The role of oral cavity colonisation is not clearly defined, several studies stating that the oral cavity represents a reservoir for H. pyloris. The presence of this rod in the dental plaque may lead to periodontitis, dental caries, dental calculus and tooth loos. Dental treatment associated with eradication therapy decreases the prevalence of oral H. pylori and improves the eradication rate of gastric H. pylori. Dental treatment in H. pylori infection management should be taken into consideration, especially in children and teens.

Learn about the Hazardous Waste Electronic Manifest System (e-Manifest)

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This webpage provides information on EPA's work toward developing a hazardous waste electronic manifest system. Information on the Hazardous Waste Electronic Manifest Establishment Act, progress on the project and frequent questions are available.

Effective degrees of freedom of a random walk on a fractal

Science.gov (United States)

Balankin, Alexander S.

2015-12-01

We argue that a non-Markovian random walk on a fractal can be treated as a Markovian process in a fractional dimensional space with a suitable metric. This allows us to define the fractional dimensional space allied to the fractal as the ν -dimensional space Fν equipped with the metric induced by the fractal topology. The relation between the number of effective spatial degrees of freedom of walkers on the fractal (ν ) and fractal dimensionalities is deduced. The intrinsic time of random walk in Fν is inferred. The Laplacian operator in Fν is constructed. This allows us to map physical problems on fractals into the corresponding problems in Fν. In this way, essential features of physics on fractals are revealed. Particularly, subdiffusion on path-connected fractals is elucidated. The Coulomb potential of a point charge on a fractal embedded in the Euclidean space is derived. Intriguing attributes of some types of fractals are highlighted.

Extrahepatic Manifestations and Autoantibodies in Patients with Hepatitis C Virus Infection

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Takashi Himoto

2012-01-01

Full Text Available Patients with chronic hepatitis C virus (HCV infection frequently have many extrahepatic manifestations, as persistent HCV infection often triggers lymphoproliferative disorders and metabolic abnormalities. These manifestations primarily include autoimmune disorders such as cryoglobulinemia, Sjögren’s syndrome, and autoimmune thyroid disorders. It has been well established that chronic HCV infection plays important roles in the production of non-organ-specific autoantibodies, including antinuclear antibodies and smooth muscle antibodies, and organ-specific autoantibodies such as thyroid autoantibodies. However, the clinical significance of autoantibodies associated with the extrahepatic manifestations caused by HCV infection has not been fully recognized. In this paper, we mainly focus on the relationship between extrahepatic manifestations and the emergence of autoantibodies in patients with HCV infection and discuss the clinical relevance of the autoantibodies in the extrahepatic disorders.

Robust H∞ Filtering for Uncertain Neutral Stochastic Systems with Markovian Jumping Parameters and Time Delay

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Yajun Li

2015-01-01

Full Text Available This paper deals with the robust H∞ filter design problem for a class of uncertain neutral stochastic systems with Markovian jumping parameters and time delay. Based on the Lyapunov-Krasovskii theory and generalized Finsler Lemma, a delay-dependent stability condition is proposed to ensure not only that the filter error system is robustly stochastically stable but also that a prescribed H∞ performance level is satisfied for all admissible uncertainties. All obtained results are expressed in terms of linear matrix inequalities which can be easily solved by MATLAB LMI toolbox. Numerical examples are given to show that the results obtained are both less conservative and less complicated in computation.

Exponential stability of delayed recurrent neural networks with Markovian jumping parameters

International Nuclear Information System (INIS)

Wang Zidong; Liu Yurong; Yu Li; Liu Xiaohui

2006-01-01

In this Letter, the global exponential stability analysis problem is considered for a class of recurrent neural networks (RNNs) with time delays and Markovian jumping parameters. The jumping parameters considered here are generated from a continuous-time discrete-state homogeneous Markov process, which are governed by a Markov process with discrete and finite state space. The purpose of the problem addressed is to derive some easy-to-test conditions such that the dynamics of the neural network is stochastically exponentially stable in the mean square, independent of the time delay. By employing a new Lyapunov-Krasovskii functional, a linear matrix inequality (LMI) approach is developed to establish the desired sufficient conditions, and therefore the global exponential stability in the mean square for the delayed RNNs can be easily checked by utilizing the numerically efficient Matlab LMI toolbox, and no tuning of parameters is required. A numerical example is exploited to show the usefulness of the derived LMI-based stability conditions

Ocular and non-ocular manifestations of hypohidrotic ectodermal dysplasia

Science.gov (United States)

Tyagi, Pallavi; Tyagi, Vipin; Hashim, Adnan A

2011-01-01

Hypohidrotic ectodermal dysplasia (HED) is a group of rare multisystemic genetic syndromes that affects ectodermal structures such as skin, hair, nails, teeth and sweat glands. The authors present a case of a child with ocular and dermatological signs of HED along with severe involvement of other multiple organ systems. The family history could be traced to four generations and there was an observed trend of increase in severity of signs and symptoms occurring at younger age. The purpose of this case report is to create awareness in ophthalmic community of its diagnosis and clinical manifestations. This case highlights the role of multidisciplinary approach for management of systemic disease, genetic evaluation of affected individuals and carriers and genetic counselling. PMID:22700604

Stability analysis of Markovian jumping stochastic Cohen—Grossberg neural networks with discrete and distributed time varying delays

International Nuclear Information System (INIS)

Ali, M. Syed

2014-01-01

In this paper, the global asymptotic stability problem of Markovian jumping stochastic Cohen—Grossberg neural networks with discrete and distributed time-varying delays (MJSCGNNs) is considered. A novel LMI-based stability criterion is obtained by constructing a new Lyapunov functional to guarantee the asymptotic stability of MJSCGNNs. Our results can be easily verified and they are also less restrictive than previously known criteria and can be applied to Cohen—Grossberg neural networks, recurrent neural networks, and cellular neural networks. Finally, the proposed stability conditions are demonstrated with numerical examples

Fuzzy Stochastic Optimal Guaranteed Cost Control of Bio-Economic Singular Markovian Jump Systems.

Science.gov (United States)

Li, Li; Zhang, Qingling; Zhu, Baoyan

2015-11-01

This paper establishes a bio-economic singular Markovian jump model by considering the price of the commodity as a Markov chain. The controller is designed for this system such that its biomass achieves the specified range with the least cost in a finite-time. Firstly, this system is described by Takagi-Sugeno fuzzy model. Secondly, a new design method of fuzzy state-feedback controllers is presented to ensure not only the regularity, nonimpulse, and stochastic singular finite-time boundedness of this kind of systems, but also an upper bound achieved for the cost function in the form of strict linear matrix inequalities. Finally, two examples including a practical example of eel seedling breeding are given to illustrate the merit and usability of the approach proposed in this paper.

MR brain scan tissues and structures segmentation: local cooperative Markovian agents and Bayesian formulation

International Nuclear Information System (INIS)

Scherrer, B.

2008-12-01

Accurate magnetic resonance brain scan segmentation is critical in a number of clinical and neuroscience applications. This task is challenging due to artifacts, low contrast between tissues and inter-individual variability that inhibit the introduction of a priori knowledge. In this thesis, we propose a new MR brain scan segmentation approach. Unique features of this approach include (1) the coupling of tissue segmentation, structure segmentation and prior knowledge construction, and (2) the consideration of local image properties. Locality is modeled through a multi-agent framework: agents are distributed into the volume and perform a local Markovian segmentation. As an initial approach (LOCUS, Local Cooperative Unified Segmentation), intuitive cooperation and coupling mechanisms are proposed to ensure the consistency of local models. Structures are segmented via the introduction of spatial localization constraints based on fuzzy spatial relations between structures. In a second approach, (LOCUS-B, LOCUS in a Bayesian framework) we consider the introduction of a statistical atlas to describe structures. The problem is reformulated in a Bayesian framework, allowing a statistical formalization of coupling and cooperation. Tissue segmentation, local model regularization, structure segmentation and local affine atlas registration are then coupled in an EM framework and mutually improve. The evaluation on simulated and real images shows good results, and in particular, a robustness to non-uniformity and noise with low computational cost. Local distributed and cooperative MRF models then appear as a powerful and promising approach for medical image segmentation. (author)

Continuous-variable quantum teleportation in bosonic structured environments

Energy Technology Data Exchange (ETDEWEB)

He Guangqiang; Zhang Jingtao; Zhu Jun; Zeng Guihua [State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronic Engineering, Shanghai Jiaotong University, Shanghai 200240 (China)

2011-09-15

The effects of dynamics of continuous-variable entanglement under the various kinds of environments on quantum teleportation are quantitatively investigated. Only under assumption of the weak system-reservoir interaction, the evolution of teleportation fidelity is analytically derived and is numerically plotted in terms of environment parameters including reservoir temperature and its spectral density, without Markovian and rotating wave approximations. We find that the fidelity of teleportation is a monotonically decreasing function for Markovian interaction in Ohmic-like environments, while it oscillates for non-Markovian ones. According to the dynamical laws of teleportation, teleportation with better performances can be implemented by selecting the appropriate time.

Clinical manifestations of gastrointestinal form of food allergy in children and approaches to its diagnosis

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Yu.R. Chernysh

2017-08-01

Full Text Available Gastrointestinal food allergy is caused by the development of allergic inflammation in the mucosa of the gastrointestinal tract. The mechanisms of this inflammation are immunogflobulin E (IgE-mediated (oral allergic syndrome, immediate gastrointestinal hypersensitivity, non-IgE-mediated (protein-induced enterocolitis syndrome, protein-induced enteropathy, protein-induced allergic proctocolitis and mixed IgE- and non-IgE-mediated reactions (eosinophilic esophagitis, eosinophilic gastritis and eosinophilic gastroenteritis. Gastrointestinal manifestations of food allergy are also combined with symptoms of atopic diseases, more often with atopic dermatitis, urticaria and angioedema. Clinical manifestations of allergic lesions of the gastrointestinal tract are different and non-specific. Common signs of gastrointestinal allergy include: vomiting (occurs from a few minutes to 4–6 hours after eating; сolic (immediately or several hours after eating; constipation; diarrhea; refusal of food (from a specific product or complete refusal to eat; abdominal pain; flatulence, the presence of mucus and eosinophils in the stool; poor appetite; headache. Differential diagnosis of gastrointestinal food allergy should be carried out with diseases such as disease and abnormalities in the development of the digestive system, mental and metabolic disorders, intoxications, infectious diseases, pancreatic endocrine gland failure, celiac disease, cystic fibrosis, immunodeficiencies, disaccharidic insufficiency, side effects of medications, endocrine pathology, irritable bowel syndrome. Methods for diagnosing gastrointestinal allergy, which currently exist, are limited and imperfect. This requires further scientific researches aimed at timely detection of this pathology, prevention in genetically predisposed children, development of optimal diagnostic algorithms, prevention of the progression of clinical manifestations, the choice of individual diet therapy and

Quantum metrology subject to spatially correlated Markovian noise: restoring the Heisenberg limit

International Nuclear Information System (INIS)

Jeske, Jan; Cole, Jared H; Huelga, Susana F

2014-01-01

Environmental noise can hinder the metrological capabilities of entangled states. While the use of entanglement allows for Heisenberg-limited resolution, the largest permitted by quantum mechanics, deviations from strictly unitary dynamics quickly restore the standard scaling dictated by the central limit theorem. Product and maximally entangled states become asymptotically equivalent when the noisy evolution is both local and strictly Markovian. However, temporal correlations in the noise have been shown to lift this equivalence while fully (spatially) correlated noise allows for the identification of decoherence-free subspaces. Here we analyze precision limits in the presence of noise with finite correlation length and show that there exist robust entangled state preparations which display persistent Heisenberg scaling despite the environmental decoherence, even for small correlation length. Our results emphasize the relevance of noise correlations in the study of quantum advantage and could be relevant beyond metrological applications. (paper)

Quantifying, characterizing, and controlling information flow in ultracold atomic gases

International Nuclear Information System (INIS)

Haikka, P.; McEndoo, S.; Maniscalco, S.; De Chiara, G.; Palma, G. M.

2011-01-01

We study quantum information flow in a model comprised of a trapped impurity qubit immersed in a Bose-Einstein-condensed reservoir. We demonstrate how information flux between the qubit and the condensate can be manipulated by engineering the ultracold reservoir within experimentally realistic limits. We show that this system undergoes a transition from Markovian to non-Markovian dynamics, which can be controlled by changing key parameters such as the condensate scattering length. In this way, one can realize a quantum simulator of both Markovian and non-Markovian open quantum systems, the latter ones being characterized by a reverse flow of information from the background gas (reservoir) to the impurity (system).

Efficient determination of the Markovian time-evolution towards a steady-state of a complex open quantum system

Science.gov (United States)

Jonsson, Thorsteinn H.; Manolescu, Andrei; Goan, Hsi-Sheng; Abdullah, Nzar Rauf; Sitek, Anna; Tang, Chi-Shung; Gudmundsson, Vidar

2017-11-01

Master equations are commonly used to describe time evolution of open systems. We introduce a general computationally efficient method for calculating a Markovian solution of the Nakajima-Zwanzig generalized master equation. We do so for a time-dependent transport of interacting electrons through a complex nano scale system in a photon cavity. The central system, described by 120 many-body states in a Fock space, is weakly coupled to the external leads. The efficiency of the approach allows us to place the bias window defined by the external leads high into the many-body spectrum of the cavity photon-dressed states of the central system revealing a cascade of intermediate transitions as the system relaxes to a steady state. The very diverse relaxation times present in the open system, reflecting radiative or non-radiative transitions, require information about the time evolution through many orders of magnitude. In our approach, the generalized master equation is mapped from a many-body Fock space of states to a Liouville space of transitions. We show that this results in a linear equation which is solved exactly through an eigenvalue analysis, which supplies information on the steady state and the time evolution of the system.

Effects of Self-Similar Collisions in the Theory of Pressure Broadening and Shift

International Nuclear Information System (INIS)

Kharintsev, S.S.; Salakhov, M.Kh.

1999-01-01

In the present paper the self-similar collision model is developed in terms of fractal Brownian motion. Within this model framework, collisions are assumed to carry a non-Markovian character and, therefore, possible memory collisional effects are not taken into account. Applying a self-similar collision model for the motion of the radiator and Anderson-Talman phase-shift theory of collisional broadening, a general formula for the correlation function in the impact limit is described. (author)

Approximate zero-variance Monte Carlo estimation of Markovian unreliability

International Nuclear Information System (INIS)

Delcoux, J.L.; Labeau, P.E.; Devooght, J.

1997-01-01

Monte Carlo simulation has become an important tool for the estimation of reliability characteristics, since conventional numerical methods are no more efficient when the size of the system to solve increases. However, evaluating by a simulation the probability of occurrence of very rare events means playing a very large number of histories of the system, which leads to unacceptable computation times. Acceleration and variance reduction techniques have to be worked out. We show in this paper how to write the equations of Markovian reliability as a transport problem, and how the well known zero-variance scheme can be adapted to this application. But such a method is always specific to the estimation of one quality, while a Monte Carlo simulation allows to perform simultaneously estimations of diverse quantities. Therefore, the estimation of one of them could be made more accurate while degrading at the same time the variance of other estimations. We propound here a method to reduce simultaneously the variance for several quantities, by using probability laws that would lead to zero-variance in the estimation of a mean of these quantities. Just like the zero-variance one, the method we propound is impossible to perform exactly. However, we show that simple approximations of it may be very efficient. (author)

General Galilei Covariant Gaussian Maps

Science.gov (United States)

Gasbarri, Giulio; Toroš, Marko; Bassi, Angelo

2017-09-01

We characterize general non-Markovian Gaussian maps which are covariant under Galilean transformations. In particular, we consider translational and Galilean covariant maps and show that they reduce to the known Holevo result in the Markovian limit. We apply the results to discuss measures of macroscopicity based on classicalization maps, specifically addressing dissipation, Galilean covariance and non-Markovianity. We further suggest a possible generalization of the macroscopicity measure defined by Nimmrichter and Hornberger [Phys. Rev. Lett. 110, 16 (2013)].

Reliability measures in item response theory: manifest versus latent correlation functions.

Science.gov (United States)

Milanzi, Elasma; Molenberghs, Geert; Alonso, Ariel; Verbeke, Geert; De Boeck, Paul

2015-02-01

For item response theory (IRT) models, which belong to the class of generalized linear or non-linear mixed models, reliability at the scale of observed scores (i.e., manifest correlation) is more difficult to calculate than latent correlation based reliability, but usually of greater scientific interest. This is not least because it cannot be calculated explicitly when the logit link is used in conjunction with normal random effects. As such, approximations such as Fisher's information coefficient, Cronbach's α, or the latent correlation are calculated, allegedly because it is easy to do so. Cronbach's α has well-known and serious drawbacks, Fisher's information is not meaningful under certain circumstances, and there is an important but often overlooked difference between latent and manifest correlations. Here, manifest correlation refers to correlation between observed scores, while latent correlation refers to correlation between scores at the latent (e.g., logit or probit) scale. Thus, using one in place of the other can lead to erroneous conclusions. Taylor series based reliability measures, which are based on manifest correlation functions, are derived and a careful comparison of reliability measures based on latent correlations, Fisher's information, and exact reliability is carried out. The latent correlations are virtually always considerably higher than their manifest counterparts, Fisher's information measure shows no coherent behaviour (it is even negative in some cases), while the newly introduced Taylor series based approximations reflect the exact reliability very closely. Comparisons among the various types of correlations, for various IRT models, are made using algebraic expressions, Monte Carlo simulations, and data analysis. Given the light computational burden and the performance of Taylor series based reliability measures, their use is recommended. © 2014 The British Psychological Society.

Non-equilibrium phase transition in a spreading process on a timeline

International Nuclear Information System (INIS)

Barato, Andre C; Hinrichsen, Haye

2009-01-01

We consider a non-equilibrium process on a timeline with discrete sites which evolves following a non-Markovian update rule in such a way that an active site at time t activates one or several sites in the future at time t+Δt. The time intervals Δt are distributed algebraically as (Δt) −1−κ , where 0<κ<1 is a control parameter. Depending on the activation rate, the system displays a non-equilibrium phase transition which may be interpreted as directed percolation transition driven by temporal Lévy flights in the limit of zero space dimensions. The critical properties are investigated by means of extensive numerical simulations and compared with field-theoretic predictions

Permanence and asymptotic behaviors of stochastic predator-prey system with Markovian switching and Lévy noise

Science.gov (United States)

Wang, Sheng; Wang, Linshan; Wei, Tengda

2018-04-01

This paper concerns the dynamics of a stochastic predator-prey system with Markovian switching and Lévy noise. First, the existence and uniqueness of global positive solution to the system is proved. Then, by combining stochastic analytical techniques with M-matrix analysis, sufficient conditions of stochastic permanence and extinction are obtained. Furthermore, for the stochastic permanence case, by means of four constants related to the stationary probability distribution of the Markov chain and the parameters of the subsystems, both the superior limit and the inferior limit of the average in time of the sample path of the solution are estimated. Finally, our conclusions are illustrated through an example.

State estimation for neural neutral-type networks with mixed time-varying delays and Markovian jumping parameters

International Nuclear Information System (INIS)

Lakshmanan, S.; Park, Ju H.; Jung, H. Y.; Balasubramaniam, P.

2012-01-01

This paper is concerned with a delay-dependent state estimator for neutral-type neural networks with mixed time-varying delays and Markovian jumping parameters. The addressed neural networks have a finite number of modes, and the modes may jump from one to another according to a Markov process. By construction of a suitable Lyapunov—Krasovskii functional, a delay-dependent condition is developed to estimate the neuron states through available output measurements such that the estimation error system is globally asymptotically stable in a mean square. The criterion is formulated in terms of a set of linear matrix inequalities (LMIs), which can be checked efficiently by use of some standard numerical packages

A discrete single server queue with Markovian arrivals and phase type group services

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Attahiru Sule Alfa

1995-01-01

Full Text Available We consider a single-server discrete queueing system in which arrivals occur according to a Markovian arrival process. Service is provided in groups of size no more than M customers. The service times are assumed to follow a discrete phase type distribution, whose representation may depend on the group size. Under a probabilistic service rule, which depends on the number of customers waiting in the queue, this system is studied as a Markov process. This type of queueing system is encountered in the operations of an automatic storage retrieval system. The steady-state probability vector is shown to be of (modified matrix-geometric type. Efficient algorithmic procedures for the computation of the rate matrix, steady-state probability vector, and some important system performance measures are developed. The steady-state waiting time distribution is derived explicitly. Some numerical examples are presented.

Classification, diagnostic criteria, and treatment recommendations for orofacial manifestations in HIV-infected pediatric patients. Collaborative Workgroup on Oral Manifestations of Pediatric HIV Infection.

Science.gov (United States)

Ramos-Gomez, F J; Flaitz, C; Catapano, P; Murray, P; Milnes, A R; Dorenbaum, A

1999-01-01

The criteria for diagnosis of HIV-related oral lesions in adults are well established, but corresponding criteria in the pediatric population are not as well defined. The Collaborative Workgroup on the Oral Manifestations of Pediatric HIV infection reached a consensus, based upon available data, as to the presumptive and definitive criteria to diagnose the oral manifestations of HIV infection in children. Presumptive criteria refer to the clinical features of the lesions, including signs and symptoms, whereas definitive criteria require specific laboratory tests. In general, it is recommended that definitive criteria be established whenever possible. Orofacial manifestations have been divided into three groups: 1) those commonly associated with pediatric HIV infection; 2) those less commonly associated with pediatric HIV infection; and 3) those strongly associated with HIV infection but rare in children. Orofacial lesions commonly associated with pediatric HIV infection include candidiasis, herpes simplex infection, linear gingival erythema, parotid enlargement, and recurrent aphthous stomatitis. In contrast, orofacial lesions strongly associated with HIV infection but rare in children include Kaposi's sarcoma, non-Hodgkin's lymphoma, and oral hairy leukoplakia. Treatment recommendations, specific for this age group, have been included for some of the more common HIV-related orofacial manifestations.

Correlation of Serotype-Specific Dengue Virus Infection with Clinical Manifestations

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Halsey, Eric S.; Marks, Morgan A.; Gotuzzo, Eduardo; Fiestas, Victor; Suarez, Luis; Vargas, Jorge; Aguayo, Nicolas; Madrid, Cesar; Vimos, Carlos; Kochel, Tadeusz J.; Laguna-Torres, V. Alberto

2012-01-01

Background Disease caused by the dengue virus (DENV) is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype. Methodology and Principal Findings Between the years 2005–2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%), DENV-2 (4.3%), DENV-3 (41.5%), or DENV-4 (14.4%). When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations. Conclusions/Significance Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype. PMID:22563516

Correlation of serotype-specific dengue virus infection with clinical manifestations.

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Eric S Halsey

Full Text Available Disease caused by the dengue virus (DENV is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4 with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype.Between the years 2005-2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%, DENV-2 (4.3%, DENV-3 (41.5%, or DENV-4 (14.4%. When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations.Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype.

Bilingualism delays clinical manifestation of Alzheimer's disease

OpenAIRE

Woumans, Evy; Santens, Patrick; Sieben, Anne; Versijpt, Jan; Stevens, Michaël; Duyck, Wouter

2015-01-01

The current study investigated the effects of bilingualism on the clinical manifestation of Alzheimer's disease (AD) in a European sample of patients. We assessed all incoming AD patients in two university hospitals within a specified timeframe. Sixty-nine monolinguals and 65 bilinguals diagnosed with probable AD were compared for time of clinical AD manifestation and diagnosis. The influence of other potentially interacting variables was also examined. Results indicated a significant delay f...

Some regularities of manifestation of synergistic effects of microplasticity under electrolytic iron hydpidation

International Nuclear Information System (INIS)

Skryabina, N.E.; Spivak, L.V.; Volyntsev, A.B.

1984-01-01

Effect of the crystalline lattice type, material chemical composition, kinds of strain and regimes of cathode polarization on the fact of appearance and magnitude of the microplastic aftereffect deformation (MAD) has been studied. Investigation of some factors determining the MAD strengthening during the electrolytic metal hydridation allows one to define the following necessary conditions for manifestation of those synergistic effects: a sufficiently high hydrogen permeability; an existence of strains gradient and hydrogen concentration across sample cross section, an existence of some specific structural state

Some regularities of manifestation of synergistic effects of microplasticity under electrolytic iron hydridation

Energy Technology Data Exchange (ETDEWEB)

Skryabina, N.E.; Spivak, L.V.; Volyntsev, A.B.

Effect of the crystalline lattice type, material chemical composition, kinds of strain and regimes of cathode polarization on the fact of appearance and magnitude of the microplastic aftereffect deformation (MAD) has been studied. Investigation of some factors determining the MAD strengthening during the electrolytic metal hydridation allows one to define the following necessary conditions for manifestation of those synergistic effects: a sufficiently high hydrogen permeability; an existence of strains gradient and hydrogen concentration across sample cross section, an existence of some specific structural state.

Are Systemic Manifestations Ascribable to COPD in Smokers? A Structural Equation Modeling Approach.

Science.gov (United States)

Boyer, Laurent; Bastuji-Garin, Sylvie; Chouaid, Christos; Housset, Bruno; Le Corvoisier, Philippe; Derumeaux, Geneviève; Boczkowski, Jorge; Maitre, Bernard; Adnot, Serge; Audureau, Etienne

2018-06-05

Whether the systemic manifestations observed in Chronic Obstructive Pulmonary Disease (COPD) are ascribable to lung dysfunction or direct effects of smoking is in debate. Structural Equations Modeling (SEM), a causal-oriented statistical approach, could help unraveling the pathways involved, by enabling estimation of direct and indirect associations between variables. The objectives of the study was to investigate the relative impact of smoking and COPD on systemic manifestations, inflammation and telomere length. In 292 individuals (103 women; 97 smokers with COPD, 96 smokers without COPD, 99 non-smokers), we used SEM to explore the pathways between smoking (pack-years), lung disease (FEV 1 , K CO ), and the following parameters: arterial stiffness (aortic pulse wave velocity, PWV), bone mineral density (BMD), appendicular skeletal muscle mass (ASMM), grip strength, insulin resistance (HOMA-IR), creatinine clearance (eGFR), blood leukocyte telomere length and inflammatory markers (Luminex assay). All models were adjusted on age and gender. Latent variables were created for systemic inflammation (inflammatory markers) and musculoskeletal parameters (ASMM, grip strength, BMD). SEM showed that most effects of smoking were indirectly mediated by lung dysfunction: e.g. via FEV 1 on musculoskeletal factor, eGFR, HOMA-IR, PWV, telomere length, CRP, white blood cells count (WBC) and inflammation factor, and via K CO on musculoskeletal factor, eGFR and PWV. Direct effects of smoking were limited to CRP and WBC. Models had excellent fit. In conclusion, SEM highlighted the major role of COPD in the occurrence of systemic manifestations while smoking effects were mostly mediated by lung function.

Novel manifestations of the Aharonov-Bohm effect in quantum rings and Moebius rings

International Nuclear Information System (INIS)

Fomin, Vladimir M.

2013-01-01

- An overview is given on the recent experimental and theoretical advancements in studies of novel manifestations of the Aharonov-Bohm quantum-interference effect for excitons confined to self assembled quantum rings and other semiconductor nanostructures with ring-like states of charge carriers as well as for electrons in Moebius rings at the micro- and nanoscale. The exciton Aharonov-Bohm effect can be effectively controlled by an out-of-plane magnetic field, a vertical electric field, a spin disorder. A 'delocalization-to-localization' transition for the electron ground state occurs in a Moebius ring as it is made more inhomogeneous. (authors)

Optimal strategy for a single-qubit gate and the trade-off between opposite types of decoherence

International Nuclear Information System (INIS)

Alicki, Robert; Horodecki, Michal; Horodecki, Ryszard; Horodecki, Pawel; Jacak, Lucjan; Machnikowski, Pawel

2004-01-01

We study reliable quantum-information processing (QIP) under two different types of environment. The first type is Markovian exponential decay, and the appropriate elementary strategy of protection of qubit is to apply fast gates. The second one is strongly non-Markovian and occurs solely during operations on the qubit. The best strategy is then to work with slow gates. If the two types are both present, one has to optimize the speed of gate. We show that such a trade-off is present for a single-qubit operation in a semiconductor quantum dot implementation of QIP, where recombination of exciton (qubit) is Markovian, while phonon dressing gives rise to the non-Markovian contribution

Memory effects in the relaxation of nonideal plasmas

International Nuclear Information System (INIS)

Bonitz, M.; Kremp, D.; Scott, D.C.; Binder, R.

1995-01-01

Traditionally, nonequilibrium properties of many-particle systems have been quite successfully described on the basis of Markovian kinetic equations, such as the Landau, Boltzmann or Lenard-Balescu equation. However, these equations have to well-known principal defects: (1) they are applicable only to time-scales bigger than the correlation time τ cor and (2) they conserve only the kinetic energy but not the total energy of the system. The latter problem is important for strongly coupled systems, where the potential energy becomes comparable to the kinetic energy. Then, e.g. the equilibrium properties will be essentially determined by interaction effects. All thermodynamic quantities and transport coefficients will contain additional correlation contributions. These requirements make it necessary to consider generalized kinetic equations which conserve total energy like have been derived by Prigogine et al., Zubarev, Klimontovich and others. In this contribution we consider the proper non-Markovian generalization of the Boltzmann equation (binary collision approximation) and of the Landau equation (Born approximation). Many-particle effects, such as Pauli blocking, initial correlations, retardation (memory), energy broadening and self energy are included. The resulting generalized kinetic equations are discussed in detail. Important limiting cases, such as following from retardation or gradient expansions, are investigated

Computed tomographic findings in manifesting carriers of Duchenne muscular dystrophy

NARCIS (Netherlands)

de Visser, M.; Verbeeten, B.

1985-01-01

Clinical and computed tomographic (CT) findings in 3 manifesting carriers of Duchenne muscular dystrophy are reported. CT proved to be an important adjunct to the clinical examination: in all our 3 cases a decrease in density was found in various non-paretic muscles

Markovian Monte Carlo program EvolFMC v.2 for solving QCD evolution equations

Science.gov (United States)

Jadach, S.; Płaczek, W.; Skrzypek, M.; Stokłosa, P.

2010-02-01

We present the program EvolFMC v.2 that solves the evolution equations in QCD for the parton momentum distributions by means of the Monte Carlo technique based on the Markovian process. The program solves the DGLAP-type evolution as well as modified-DGLAP ones. In both cases the evolution can be performed in the LO or NLO approximation. The quarks are treated as massless. The overall technical precision of the code has been established at 5×10. This way, for the first time ever, we demonstrate that with the Monte Carlo method one can solve the evolution equations with precision comparable to the other numerical methods. New version program summaryProgram title: EvolFMC v.2 Catalogue identifier: AEFN_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFN_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including binary test data, etc.: 66 456 (7407 lines of C++ code) No. of bytes in distributed program, including test data, etc.: 412 752 Distribution format: tar.gz Programming language: C++ Computer: PC, Mac Operating system: Linux, Mac OS X RAM: Less than 256 MB Classification: 11.5 External routines: ROOT ( http://root.cern.ch/drupal/) Nature of problem: Solution of the QCD evolution equations for the parton momentum distributions of the DGLAP- and modified-DGLAP-type in the LO and NLO approximations. Solution method: Monte Carlo simulation of the Markovian process of a multiple emission of partons. Restrictions:Limited to the case of massless partons. Implemented in the LO and NLO approximations only. Weighted events only. Unusual features: Modified-DGLAP evolutions included up to the NLO level. Additional comments: Technical precision established at 5×10. Running time: For the 10 6 events at 100 GeV: DGLAP NLO: 27s; C-type modified DGLAP NLO: 150s (MacBook Pro with Mac OS X v.10

Order-disorder transitions in time-discrete mean field systems with memory: a novel approach via nonlinear autoregressive models

International Nuclear Information System (INIS)

Frank, T D; Mongkolsakulvong, S

2015-01-01

In a previous study strongly nonlinear autoregressive (SNAR) models have been introduced as a generalization of the widely-used time-discrete autoregressive models that are known to apply both to Markov and non-Markovian systems. In contrast to conventional autoregressive models, SNAR models depend on process mean values. So far, only linear dependences have been studied. We consider the case in which process mean values can have a nonlinear impact on the processes under consideration. It is shown that such models describe Markov and non-Markovian many-body systems with mean field forces that exhibit a nonlinear impact on single subsystems. We exemplify that such nonlinear dependences can describe order-disorder phase transitions of time-discrete Markovian and non-Markovian many-body systems. The relevant order parameter equations are derived and issues of stability and stationarity are studied. (paper)

Asymptomatic hyper-creatine-kinase-emia as sole manifestation of inclusion body myositis

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Josef Finsterer

2013-06-01

Full Text Available Sporadic inclusion body myositis (sIBM usually manifests with painless weakness of the hand, finger and hip flexors. Absence of symptoms or signs, but mild hyper-CK-emia as the sole manifestation of IBM, has not been reported. We report the case of a 73-year-old male who presented with asymptomatic recurrent hyper-CK-emia ranging from 200 to 1324 U/L (n<171 U/L, since 10 years. Clinical neurologic investigation, nerve conduction studies and EMG were non-informative. Muscle biopsy surprisingly revealed sIBM. sIBM may be asymptomatic and may manifest with hyper-CK-emia exclusively. So, it has to be included in the differential diagnoses of asymptomatic hyper-CK-emia.

Sclerodermatomyositis, ocular manifestations.

Science.gov (United States)

Pedroza-Seres, M; Serna-Ojeda, J C; Flores-Suárez, L F

2017-07-01

Sclerodermatomyositis is an overlap syndrome of myositis and scleroderma, with dermatological, muscular and joint involvement, but may also present with ocular manifestations. A 57 year-old woman presented with ophthalmological manifestations, including scleral thinning 360°, and the presence of cells in the anterior and posterior chamber. Oriented physical examination and laboratory studies led to the diagnosis, with the need for systemic treatment. Sclerodermatomyositis is a rare disease. Its diagnosis needs thorough clinical and laboratory studies, and its management should be multidisciplinary when inflammatory ocular manifestations may be present. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

Ocular Manifestations of Acquired Immunodeficiency Syndrome.

Science.gov (United States)

Kim, Young Shin; Sun, Hae Jung; Kim, Tae Hyong; Kang, Kui Dong; Lee, Sung Jin

2015-08-01

To investigate the patterns and risk factors of the ocular manifestations of acquired immunodeficiency syndrome (AIDS) and their correlation with CD4+ count in the era of highly active antiretroviral therapy (HAART). This retrospective study examined 127 AIDS patients who presented to Soonchunhyang University Hospital. Data were collected from patient interviews, clinical examinations, and laboratory investigations. Ophthalmologic examinations included the best-corrected visual acuity, intraocular pressure, anterior segment and adnexal examination, and dilated fundus examination. Of the 127 patients with AIDS, 118 were on HAART and 9 were not. The mean CD4+ count was 266.7 ± 209.1 cells/µL. There were ocular manifestations in 61 patients (48.0%). The incidence of anterior segment manifestations was higher than posterior segment manifestations at 28.3% and 19.7%, respectively. The mean CD4+ count was significantly (p AIDS. In this study, anterior segment and external ocular manifestations occurred more frequently than posterior segment manifestations. Also, the mean CD4+ count was significantly lower in patients with posterior segment ocular manifestations versus anterior segment ocular manifestations. We found that CD4+ count and age >35 years were independent risk factors for developing ocular manifestations.

Clinical manifestations and management of Gaucher disease.

Science.gov (United States)

Linari, Silvia; Castaman, Giancarlo

2015-01-01

Gaucher disease is a rare multi-systemic metabolic disorder caused by the inherited deficiency of the lysosomal enzyme β-glucocerebrosidase, which leads to the accumulation of its normal substrate, glucocerebroside, in tissue macrophages with damage to haematological, visceral and bone systems. Anaemia, thrombocytopenia, enlargement of liver and/or spleen, skeletal abnormalities (osteopenia, lytic lesions, pathological fractures, chronic bone pain, bone crisis, bone infarcts, osteonecrosis and skeletal deformities) are typical manifestations of the most prevalent form of the disease, the so-called non-neuronopathic type 1. However, severity and coexistence of different symptoms are highly variable. The determination of deficient β-glucocerebrosidase activity in leukocytes or fibroblasts by enzymatic assay is the gold standard for the diagnosis of Gaucher disease. Comprehensive and reproducible evaluation and monitoring of all clinically relevant aspects are fundamental for the effective management of Gaucher disease patients. Enzyme replacement therapy has been shown to be effective in reducing glucocerebroside storage burden and diminishing the deleterious effects caused by its accumulation. Tailored treatment plan for each patient should be directed to symptom relief, general improvement of quality of life, and prevention of irreversible damage.

Neuropsychiatric manifestations of scrub typhus

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Sanjay K Mahajan

2017-01-01

Full Text Available Scrub typhus is caused by Orientia tsutsugamushi characterized by focal or disseminated vasculitis and perivasculitis which may involve the lungs, heart, liver, spleen and central nervous system. It was thought to have been eradicated from India. Recently it is being reported from many areas of India. The clinical picture and severity of the symptoms varies widely. The neurological manifestations of scrub typhus are not uncommon but are diverse. Meningoencephalitis is classical manifestation of scrub typhus but cerebellitis, cranial nerve palsies, plexopathy, transverse myelitis, neuroleptic malignant syndrome and Guillan-Barré syndrome are other manifestations reported in literature. The availability of literature on the neurological manifestations of scrub typhus is limited to case reports mainly. This article reviews various neurological manifestations of scrub typhus reported in literature.

A finite capacity queue with Markovian arrivals and two servers with group services

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S. Chakravarthy

1994-01-01

Full Text Available In this paper we consider a finite capacity queuing system in which arrivals are governed by a Markovian arrival process. The system is attended by two exponential servers, who offer services in groups of varying sizes. The service rates may depend on the number of customers in service. Using Markov theory, we study this finite capacity queuing model in detail by obtaining numerically stable expressions for (a the steady-state queue length densities at arrivals and at arbitrary time points; (b the Laplace-Stieltjes transform of the stationary waiting time distribution of an admitted customer at points of arrivals. The stationary waiting time distribution is shown to be of phase type when the interarrival times are of phase type. Efficient algorithmic procedures for computing the steady-state queue length densities and other system performance measures are discussed. A conjecture on the nature of the mean waiting time is proposed. Some illustrative numerical examples are presented.

Effect of turbulent collisions on diffusion in stationary plasma turbulence

International Nuclear Information System (INIS)

Xia, H.; Ishihara, O.

1990-01-01

Recently the velocity diffusion process was studied by the generalized Langevin equation derived by the projection operator method. The further study shows that the retarded frictional function plays an important role in suppressing particle diffusion in the velocity space in stronger turbulence as much as the resonance broadening effect. The retarded frictional effect, produced by the effective collisions due to the plasma turbulence is assumed to be a Gaussian, but non-Markovian and non-wide-sense stationary process. The relations between the proposed formulation and the extended resonance broadening theory is discussed. The authors also carry out test particle numerical experiment for Langmuir turbulence to test the theories. In a stronger turbulence a deviation of the diffusion rate from the one predicted by both the quasilinear and the extended resonance theories has been observed and is explained qualitatively by the present formulation

Memory effects, two color percolation, and the temperature dependence of Mott variable-range hopping

Science.gov (United States)

Agam, Oded; Aleiner, Igor L.

2014-06-01

There are three basic processes that determine hopping transport: (a) hopping between normally empty sites (i.e., having exponentially small occupation numbers at equilibrium), (b) hopping between normally occupied sites, and (c) transitions between normally occupied and unoccupied sites. In conventional theories all these processes are considered Markovian and the correlations of occupation numbers of different sites are believed to be small (i.e., not exponential in temperature). We show that, contrary to this belief, memory effects suppress the processes of type (c) and manifest themselves in a subleading exponential temperature dependence of the variable-range hopping conductivity. This temperature dependence originates from the property that sites of type (a) and (b) form two independent resistor networks that are weakly coupled to each other by processes of type (c). This leads to a two-color percolation problem which we solve in the critical region.

Semigroup evolution in the Wigner-Weisskopf pole approximation with Markovian spectral coupling

International Nuclear Information System (INIS)

Shikerman, F.; Peer, A.; Horwitz, L. P.

2011-01-01

We establish the relation between the Wigner-Weisskopf theory for the description of an unstable system and the theory of coupling to an environment. According to the Wigner-Weisskopf general approach, even within the pole approximation, the evolution of a total system subspace is not an exact semigroup for multichannel decay unless the projectors into eigenstates of the reduced evolution generator W(z) are orthogonal. With multichannel decay, the projectors must be evaluated at different pole locations z α ≠z β , and since the orthogonality relation does not generally hold at different values of z, the semigroup evolution is a poor approximation for the multichannel decay, even for very weak coupling. Nevertheless, if the theory is generalized to take into account interactions with an environment, one can ensure orthogonality of the W(z) projectors regardless of the number of poles. Such a possibility occurs when W(z), and hence its eigenvectors, is independent of z, which corresponds to the Markovian limit of the coupling to the continuum spectrum.

Semigroup evolution in the Wigner-Weisskopf pole approximation with Markovian spectral coupling

Energy Technology Data Exchange (ETDEWEB)

Shikerman, F.; Peer, A. [Physics department and BINA center for nano-technology, Bar Ilan University, Ramat Gan 52900 (Israel); Horwitz, L. P. [Physics department and BINA center for nano-technology, Bar Ilan University, Ramat Gan 52900 (Israel); School of Physics, Tel-Aviv University, Ramat-Aviv 69978 (Israel); Department of Physics, Ariel University Center of Samaria, Ariel 40700 (Israel)

2011-07-15

We establish the relation between the Wigner-Weisskopf theory for the description of an unstable system and the theory of coupling to an environment. According to the Wigner-Weisskopf general approach, even within the pole approximation, the evolution of a total system subspace is not an exact semigroup for multichannel decay unless the projectors into eigenstates of the reduced evolution generator W(z) are orthogonal. With multichannel decay, the projectors must be evaluated at different pole locations z{sub {alpha}}{ne}z{sub {beta}}, and since the orthogonality relation does not generally hold at different values of z, the semigroup evolution is a poor approximation for the multichannel decay, even for very weak coupling. Nevertheless, if the theory is generalized to take into account interactions with an environment, one can ensure orthogonality of the W(z) projectors regardless of the number of poles. Such a possibility occurs when W(z), and hence its eigenvectors, is independent of z, which corresponds to the Markovian limit of the coupling to the continuum spectrum.

Dengue encephalitis–A rare manifestation of dengue fever

OpenAIRE

Madi, Deepak; Achappa, Basavaprabhu; Ramapuram, John T; Chowta, Nityananda; Laxman, Mridula; Mahalingam, Soundarya

2014-01-01

The clinical spectrum of dengue fever ranges from asymptomatic infection to dengue shock syndrome. Dengue is classically considered a non-neurotropic virus. Neurological complications are not commonly seen in dengue. The neurological manifestations seen in dengue are encephalitis, meningitis, encephalopathy, stroke and Guillain-Barré syndrome. Dengue encephalitis is a rare disease. We report an interesting case of dengue encephalitis from Southern India. A 49-year-old gentleman presented with...

Atomic theory of viscoelastic response and memory effects in metallic glasses

Science.gov (United States)

Cui, Bingyu; Yang, Jie; Qiao, Jichao; Jiang, Minqiang; Dai, Lanhong; Wang, Yun-Jiang; Zaccone, Alessio

2017-09-01

An atomic-scale theory of the viscoelastic response of metallic glasses is derived from first principles, using a Zwanzig-Caldeira-Leggett system-bath Hamiltonian as a starting point within the framework of nonaffine linear response to mechanical deformation. This approach provides a generalized Langevin equation (GLE) as the average equation of motion for an atom or ion in the material, from which non-Markovian nonaffine viscoelastic moduli are extracted. These can be evaluated using the vibrational density of states (DOS) as input, where the boson peak plays a prominent role in the mechanics. To compare with experimental data for binary ZrCu alloys, a numerical DOS was obtained from simulations of this system, which also take electronic degrees of freedom into account via the embedded-atom method for the interatomic potential. It is shown that the viscoelastic α -relaxation, including the α -wing asymmetry in the loss modulus, can be very well described by the theory if the memory kernel (the non-Markovian friction) in the GLE is taken to be a stretched-exponential decaying function of time. This finding directly implies strong memory effects in the atomic-scale dynamics and suggests that the α -relaxation time is related to the characteristic time scale over which atoms retain memory of their previous collision history. This memory time grows dramatically below the glass transition.

Rheumatic manifestations at presentation of Hodgkin's disease and non-Hodgkin's malignant lymphoma. A national survey of one hundred forty-six patients

International Nuclear Information System (INIS)

Gaudin, P.; Rozand, Y.; Fauconnier, J.; Phelip, X.

1995-01-01

The authors report the findings of a national survey conducted at the request for the French Society for Rheumatology to list the rheumatic manifestations that can be inaugural in Hodgkin's disease on non-Hodgkin's malignant lymphoma. This was an exploratory, retrospective, descriptive study of 146 patients from 22 rheumatology departments. A number of clinical features (young male, nocturnal sweats, generalized pruritus, protracted fever, central or peripheral lymphadenopathy) and laboratory test abnormalities (evidence of severe inflammation) considerably increased the likelihood of Hodgkin's disease rather than malignant lymphoma. The diagnosis of bony involvement requires multidisciplinary studies of tumor specimens. (authors). 4 figs., 7 tabs., 71 refs

Depolarizing channel as a completely positive map with memory

International Nuclear Information System (INIS)

Daffer, Sonja; McIver, John K.; Wodkiewicz, Krzysztof; Cresser, James D.

2004-01-01

The prevailing description for dissipative quantum dynamics is given by the Lindblad form of a Markovian master equation, used under the assumption that memory effects are negligible. However, in certain physical situations, the master equation is essentially of a non-Markovian nature. In this paper we examine master equations that possess a memory kernel, leading to a replacement of white noise by colored noise. The conditions under which this leads to a completely positive, trace-preserving map are discussed for an exponential memory kernel

Kraus map for non-Markovian quantum dynamics driven by a thermal reservoir

NARCIS (Netherlands)

van Wonderen, A.J.; Suttorp, L.G.

2013-01-01

Starting from unitary dynamics we study the evolution in time of a non-relativistic quantum system that exchanges energy with a thermal reservoir of harmonic oscillators. System and reservoir are assumed to be initially decorrelated. Reservoir correlation functions are factorized by means of a Kraus

Bifurcation dynamics of the tempered fractional Langevin equation

Energy Technology Data Exchange (ETDEWEB)

Zeng, Caibin, E-mail: macbzeng@scut.edu.cn; Yang, Qigui, E-mail: qgyang@scut.edu.cn [School of Mathematics, South China University of Technology, Guangzhou 510640 (China); Chen, YangQuan, E-mail: ychen53@ucmerced.edu [MESA LAB, School of Engineering, University of California, Merced, 5200 N. Lake Road, Merced, California 95343 (United States)

2016-08-15

Tempered fractional processes offer a useful extension for turbulence to include low frequencies. In this paper, we investigate the stochastic phenomenological bifurcation, or stochastic P-bifurcation, of the Langevin equation perturbed by tempered fractional Brownian motion. However, most standard tools from the well-studied framework of random dynamical systems cannot be applied to systems driven by non-Markovian noise, so it is desirable to construct possible approaches in a non-Markovian framework. We first derive the spectral density function of the considered system based on the generalized Parseval's formula and the Wiener-Khinchin theorem. Then we show that it enjoys interesting and diverse bifurcation phenomena exchanging between or among explosive-like, unimodal, and bimodal kurtosis. Therefore, our procedures in this paper are not merely comparable in scope to the existing theory of Markovian systems but also provide a possible approach to discern P-bifurcation dynamics in the non-Markovian settings.

Surgical manifestations of filariasis

Directory of Open Access Journals (Sweden)

Subrahmanyam M

1978-01-01

Full Text Available Surgical manifestations of filariasis as seen in 150 cases over a period of three years in the department of Surgery, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Wardha are reviewed. The genital manifestations are more common than the elephantiasis in this endemic zone.

Respiratory manifestations of gastro-oesophageal reflux in children.

Science.gov (United States)

de Benedictis, Fernando Maria; Bush, Andrew

2018-03-01

Gastro-oesophageal reflux disease (GORD) is a complex problem in children. Suspected respiratory manifestations of GORD, such as asthma, chronic cough and laryngitis, are commonly encountered in the paediatric practice, but continue to be entities with more questions than answers. The accuracy of diagnostic tests (ie, pH or pH-impedance monitoring, laryngoscopy, endoscopy) for patients with suspected extraoesophageal manifestations of GORD is suboptimal and therefore whether there is a causal relationship between these conditions remains largely undetermined. An empiric trial of proton pump inhibitors can help individual children with undiagnosed respiratory symptoms and suspicion of GORD, but the response to therapy is unpredictable, and in any case what may be being observed is spontaneous improvement. Furthermore, the safety of these agents has been called into question. Poor response to antireflux therapy is an important trigger to search for non-gastro-oesophageal reflux causes for patients' symptoms. Evidence for the assessment of children with suspected extraoesophageal manifestations of GORD is scanty and longitudinal studies with long-term follow-up are urgently required. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Recurrent Hyponatremia as Presenting Manifestation of Pituitary Macroadenoma

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Rajput R.

2017-05-01

Full Text Available Hyponatremia is commonly seen electrolyte disturbance clinically. It is potentially life-threatening and requires prompt diagnosis and treatment. Non-functioning pituitary macroadenoma generally presents with a headache, visual disturbances, and the diagnosis is often delayed because of nonspecific nature of symptoms. Hyponatremia being initial manifestation before other common symptoms of pituitary macroadenoma is rare. We present a case of 55-year-old male with recurrent episodes of hyponatremia who was found to non-functioning pituitary macroadenoma along with panhypopituitarism. He was managed with hormone replacements. Our case highlights the importance of correct diagnosis of hyponatremia, measurement of the thyroid, adrenal and pituitary function in cases of hyponatremia.

Measuring the effective phonon density of states of a quantum dot in cavity quantum electrodynamics

DEFF Research Database (Denmark)

Madsen, Kristian Høeg; Nielsen, Per Kær; Kreiner-Møller, Asger

2013-01-01

We employ detuning-dependent decay-rate measurements of a quantum dot in a photonic-crystal cavity to study the influence of phonon dephasing in a solid-state quantum-electrodynamics experiment. The experimental data agree with a microscopic non-Markovian model accounting for dephasing from...... longitudinal acoustic phonons, and the analysis explains the difference between nonresonant cavity feeding in different nanocavities. From the comparison between experiment and theory we extract the effective phonon density of states experienced by the quantum dot in the nanocavity. This quantity determines...

Non-Markovian effects on the dynamics of bubble growth in hot asymmetric nuclear matter

International Nuclear Information System (INIS)

Kolomietz, V.M.; Sanzhur, A.I.; Shlomo, S.

2003-01-01

We study the conditions for the generation and the dynamical evolution of embryonic overcritical vapor bubbles in an overheated asymmetric nuclear matter. We show that the Fermi-surface distortion and memory effects significantly hinder the growth of the bubbles. Moreover, the growth of the bubble is accompanied by characteristic oscillations of its radius R. The characteristic energy E, the damping parameter Γ, and the instability growth rate parameter ζ, depend on the relaxation time τ. The characteristic oscillations disappear in the short relaxation time limit τ→0. Our approach ignores the fluctuations of the particle numbers in the bubble region and the finite diffuse layer of the bubble. The minimum size of the critical radius R * for which our approach applies is determined by the condition a/R * <<1, where a=0.5-1 fm is the temperature-dependent surface thickness of the bubble

Musculoskeletal manifestations of bacterial endocarditis

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Érika Bevilaqua Rangel

2000-09-01

Full Text Available CONTEXT: The incidence of staphylococcal infection has been increasing during the last 20 years. OBJECTIVE: Report a case of staphylococcal endocarditis preceded by musculoskeletal manifestations, which is a rare form of clinical presentation. DESIGN: Case report. CASE REPORT: A 45-year-old-man, without addictions and without known previous cardiopathy, was diagnosed as having definitive acute bacterial endocarditis due to Staphylococcus aureus. Its etiology was community-acquired, arising from a non-apparent primary focus. In addition, the musculoskeletal symptoms preceded the infective endocarditis (IE by about 1 month, which occurred together with other symptoms, e.g. mycotic aneurysms and petechiae. Later, the patient showed perforation of the mitral valve and moderate mitral insufficiency with clinical control.

Cardiac tamponade as the initial manifestation of pulmonary adenocarcinoma

International Nuclear Information System (INIS)

Letonja, M.; Debeljak, A.

2007-01-01

Background. Neoplastic pericarditis can be presented as acute pericarditis, pericardial effusion, effusive constrictive pericarditis or cardiac tamponade. For the majority of patients, a clinical manifestation of neoplastic pericarditis is absent or remains unrecognised during their life. Case report: A 69-year-old non-smoking woman with acute dyspnoea, tachycardia, jugular venous distension, hepatomegaly and right side pleural effusion was presented in the emergency department. The roentgen picture of the chest confirmed pleural effusion and revealed enlarged heart. An emergency echocardiogram established the diagnosis of cardiac tamponade. The patient improved immediately after the therapeutic pericardiocentesis. Cytology of pericardial fluid confirmed malignant glandular cells, consistent with metastatic adenocarcinoma. A computed chest tomography showed a right side pleural effusion and a solitary round lesion in the right lower lobe of the lung. Bronchoscopy with fundoscopic lung biopsy and brushing revealed adenocarcinoma. Cardiac tamponade as the initial manifestation of malignancy is rare and rare is also malignant pericardial effusion due the adenocarcinoma of the lung in a non-smoking woman. The presented patient had one of the longest survival reported in literature despite a limited life expectancy regardless of the treatment in the patient presented with neoplastic pericarditis. (author)

Extrathoracic manifestations of tuberculosis

International Nuclear Information System (INIS)

Kienzl-Palma, D.; Prosch, H.

2016-01-01

Besides the lungs, tuberculosis (TB) can affect any organ system. In most cases, extrathoracic TB occurs in immunosuppressed patients as part of a severe illness via hematogenous spread. Extrathoracic involvement most commonly involves abdominal organs, especially the urogenital tract and less commonly the central nervous system (CNS) and the musculoskeletal system. Most frequently, computed tomography (CT) is used for detecting extrathoracic TB manifestations, except for CNS and musculoskeletal manifestations, where contrast-enhanced magnetic resonance imaging (MRI) is the gold standard. Extrathoracic manifestations of TB may be indistinguishable from inflammatory or malignant causes. Due to unspecific symptoms the diagnosis is often delayed. This article summarizes and discusses the various radiological manifestations of extrathoracic manifestation of TB. Radiological modalities for screening extrathoracic TB are CT and MRI. Conventional X-radiographs do not play a role in the diagnosis of extrathoracic TB. The possibility of extrathoracic TB should be considered particularly in immunosuppressed patients, such as the homeless, alcoholics or drug addicts or in patients with an immigrant background from the endemic areas of TB. The most likely site of extrathoracic TB is the abdomen; however, infections of the CNS or musculoskeletal systems and multisystem infections can also occur. In patients with suspected extrathoracic TB, radiological modalities for screening are CT, especially for abdominal infections and lymphadenopathy and MRI with contrast media for the musculoskeletal system and the CNS. (orig.) [de

Amplification of non-Markovian decay due to bound state absorption into continuum

International Nuclear Information System (INIS)

Garmon, S.; Simine, L.; Segal, D.; Petrosky, T.

2013-01-01

It is known that quantum systems yield non-exponential (power law) decay on long time scales, associated with continuum threshold effects contributing to the survival probability for a prepared initial state. For an open quantum system consisting of a discrete state coupled to continuum, we study the case in which a discrete bound state of the full Hamiltonian approaches the energy continuum as the system parameters are varied. We find in this case that at least two regions exist yielding qualitatively different power law decay behaviors; we term these the long time 'near zone' and long time 'far zone'. In the near zone the survival probability falls off according to a t -1 power law, and in the far zone i t falls off as t -3 . We show that the timescale T Q separating these two regions is inversely related to the gap between the discrete bound state energy and the continuum threshold. In the case that the bound state is absorbed into the continuum and vanishes, then the time scale T Q diverges and the survival probability follows the t -1 power law even on asymptotic scales. Conversely, one could study the case of an anti-bound state approaching the threshold before being ejected from the continuum to form a bound state. Again the t -1 power law dominates precisely at the point of ejection. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Nasal manifestations in chromium industry workers.

Science.gov (United States)

Aiyer, R G; Kumar, Gaurav

2003-04-01

People working in mines, plating factories, cement industries are mainly exposed to chrome substances, IIexavalent chromium has been implicated for its toxic effect on the nasal mucosa. Hereby we present a rare study of 28 patients who attended out patient department of Otorhinolaryngology at SSG Hospital, Baroda from a nearby chromium industry. This study aims to present various nasal manifestations of toxic effects of prolonged chromium exposure.

Manifestations and possible sources of lunar transient phenomena (LTP)

International Nuclear Information System (INIS)

Cameron, W.S.

1975-01-01

Several different manifestations of lunar transient phenomena (LTP) have been reported. These include: (1) brightenings--both sudden and slow, (2) reddish--both bright and dull, (3) bluish--both bright and dull, (4) fairly abrupt dimmings or darkenings, and (5) obscurations, which may be accompanied by any of the other four manifestations. Approximately 200 lunar features exhibiting such anomalies have been reported at least once, but 80% of all observations are found in less than a dozen sites and 60% are found in about one-half dozen sites. An observing program is being conducted for the Association of Lunar and Planetary Observers which is designed to monitor the LTP sites, the seismic epicenter sites and non-LTP comparison sites. It addresses the ''brightenings'' category of observations and is designed to establish normal brightness of each observed feature for all phases of a lunation. It also seeks to establish a quantified ''seeing'' scale. About one-half dozen observers have reported albedo measures (estimated from an albedo scale set up by each observer). The most extensive new data on albedo versus age (phase of Moon) are for the crater Dawes. Several LTP effects have been discerned in Dawes. In addition, seeing estimates, based on the behavior of a star's diffraction disk, provided some unexpected results when disk behavior is compared with other subjective estimates of seeing

Skin Manifestations of Endocrine Diseases.

Science.gov (United States)

Demirkesen, Cuyan

2015-01-01

Endocrine diseases may result in changes in cutaneous function and morphology, which cause various skin manifestations, including nonspecific or pathognomonic signs. Some of these manifestations are already known dermatologic diseases with only increased frequency in this patient group. As a result the skin may the play role of a screen displaying endocrine disorders, either due to hormone excess or deficiency. Awareness of the skin manifestations may permit prompt and adequate approach to the patients, and therefore facilitate the early diagnosis of the endocrine disease and even be life saving. Some of these manifestations may be recognized clinically, but sometimes they need to be confirmed histopathologically. In this article, many endocrine diseases and their associated skin lesions will be reviewed briefly.

Neurological Manifestations In Inflammatory Bowel Disease

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youssef HNACH

2015-06-01

Full Text Available IntroductionThe purpose of this retrospective study was to report neurological manifestations noted in patients who were monitored for inflammatory bowel disease, in order to document the pathophysiological, clinical, progressive, and therapeutic characteristics of this entity.Material and methodsWe conducted a retrospective study on patients monitored -in the gastroenterology service in Ibn Sina Hospital in Rabat, Morocco- for inflammatory bowel disease from 1992 till 2013 and who developed neurological manifestations during its course. Patients with iatrogenic complications were excluded, as well as patients with cerebrovascular risk factors.ResultsThere were 6 patients, 4 of whom have developed peripheral manifestations. Electromyography enabled the diagnosis to be made and the outcome was favorable with disappearance of clinical manifestations and normalization of the electromyography.The other 2 patients, monitored for Crohn’s disease, developed ischemic stroke. Cerebral computed tomography angiography provided positive and topographic diagnosis. Two patients were admitted to specialized facilities.ConclusionNeurological manifestations in inflammatory bowel disease are rarely reported.  Peripheral neuropathies and stroke remain the most common manifestations. The mechanisms of these manifestations are not clearly defined yet. Currently, we hypothesize the interaction of immune mediators.

Clinical manifestations and managements in jellyfish envenomation A systematic review

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Negar Taheri

2013-11-01

Full Text Available Background: The phylum Cnidarians have over nine thousand species that approximately, one hundred species are dangerous for humans. Annually, a large number of deaths were reported due to jellyfish stings. The manifestations depend on their species and kind of venoms, and include the local and systemic manifestations. A number of methods and compounds were used and under investigation for management of injuries with jellyfishes. Due to the lack of an integrated systematic review, the current study was done. Materials and Methods: The PubMed data bank was searched for the term “Jellyfish”. A total of 1677 papers were found. These papers were divided into three categories: medical, biomedical and biotechnological fields. The medical category was further divided into three subcategories comprising systemic manifestations, cutaneous manifestations and treatments for the stings of jellyfishes. The biomedical category was further subdivided into genomics, proteomics, and biology of venoms, mechanisms of actions and products of biomedical significance. In this part of systematic review, the medical aspects of injuries with jellyfishes were evaluated. Results: The clinical manifestations in jellyfish envenomation depend on their species and the nature of venoms. The most common clinical manifestations of jellyfish stings are cutaneous presentations like urticasia, erythema, swelling, vesicles and severe dermonectoric manifestations. Systemic manifestations were seen in the stings of box jellyfishes, Portuguese man-of-war and in Irukandji syndrome. The most common recommendations for jellyfish envenomation managements include decreasing the local effects of venom, prevention of the venomous nematocysts release, and Controlling of systemic reactions. Application of commercial vinegar (4 - 6% acetic acid, hot water immersion (HWI (42 ° C for 20 minutes, ice packs, sea water rinsing for inactivating nematocysts, administration of topical and parenteral

Natural variation in sensory-motor white matter organization influences manifestations of Huntington's disease.

Science.gov (United States)

Orth, Michael; Gregory, Sarah; Scahill, Rachael I; Mayer, Isabella Sm; Minkova, Lora; Klöppel, Stefan; Seunarine, Kiran K; Boyd, Lara; Borowsky, Beth; Reilmann, Ralf; Bernhard Landwehrmeyer, G; Leavitt, Blair R; Roos, Raymund Ac; Durr, Alexandra; Rees, Geraint; Rothwell, John C; Langbehn, Douglas; Tabrizi, Sarah J

2016-12-01

While the HTT CAG-repeat expansion mutation causing Huntington's disease (HD) is highly correlated with the rate of pathogenesis leading to disease onset, considerable variance in age-at-onset remains unexplained. Therefore, other factors must influence the pathogenic process. We asked whether these factors were related to natural biological variation in the sensory-motor system. In 243 participants (96 premanifest and 35 manifest HD; 112 controls), sensory-motor structural MRI, tractography, resting-state fMRI, electrophysiology (including SEP amplitudes), motor score ratings, and grip force as sensory-motor performance were measured. Following individual modality analyses, we used principal component analysis (PCA) to identify patterns associated with sensory-motor performance, and manifest versus premanifest HD discrimination. We did not detect longitudinal differences over 12 months. PCA showed a pattern of loss of caudate, grey and white matter volume, cortical thickness in premotor and sensory cortex, and disturbed diffusivity in sensory-motor white matter tracts that was connected to CAG repeat length. Two further major principal components appeared in controls and HD individuals indicating that they represent natural biological variation unconnected to the HD mutation. One of these components did not influence HD while the other non-CAG-driven component of axial versus radial diffusivity contrast in white matter tracts were associated with sensory-motor performance and manifest HD. The first component reflects the expected CAG expansion effects on HD pathogenesis. One non-CAG-driven component reveals an independent influence on pathogenesis of biological variation in white matter tracts and merits further investigation to delineate the underlying mechanism and the potential it offers for disease modification. Hum Brain Mapp 37:4615-4628, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Arrhythmia as a cardiac manifestation in MELAS syndrome.

Science.gov (United States)

Thomas, Tamara; Craigen, William J; Moore, Ryan; Czosek, Richard; Jefferies, John L

2015-09-01

A 44-year-old female with a diagnosis of mitochondrial myopathy, encephalopathy and stroke-like episodes (MELAS) syndrome had progressive left ventricular hypertrophy (LVH) on echocardiogram. A Holter monitor demonstrated episodes of non-sustained atrial tachycardia, a finding not been previously described in this population. This unique case of MELAS syndrome demonstrates the known associated cardiac manifestation of LVH and the new finding of atrial tachycardia which may represent the potential for subclinical arrhythmia in this population.

Multi-scale inference of interaction rules in animal groups using Bayesian model selection.

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Richard P Mann

2012-01-01

Full Text Available Inference of interaction rules of animals moving in groups usually relies on an analysis of large scale system behaviour. Models are tuned through repeated simulation until they match the observed behaviour. More recent work has used the fine scale motions of animals to validate and fit the rules of interaction of animals in groups. Here, we use a Bayesian methodology to compare a variety of models to the collective motion of glass prawns (Paratya australiensis. We show that these exhibit a stereotypical 'phase transition', whereby an increase in density leads to the onset of collective motion in one direction. We fit models to this data, which range from: a mean-field model where all prawns interact globally; to a spatial Markovian model where prawns are self-propelled particles influenced only by the current positions and directions of their neighbours; up to non-Markovian models where prawns have 'memory' of previous interactions, integrating their experiences over time when deciding to change behaviour. We show that the mean-field model fits the large scale behaviour of the system, but does not capture fine scale rules of interaction, which are primarily mediated by physical contact. Conversely, the Markovian self-propelled particle model captures the fine scale rules of interaction but fails to reproduce global dynamics. The most sophisticated model, the non-Markovian model, provides a good match to the data at both the fine scale and in terms of reproducing global dynamics. We conclude that prawns' movements are influenced by not just the current direction of nearby conspecifics, but also those encountered in the recent past. Given the simplicity of prawns as a study system our research suggests that self-propelled particle models of collective motion should, if they are to be realistic at multiple biological scales, include memory of previous interactions and other non-Markovian effects.

A Rare Manifestation of Hypothyroid Myopathy: Hoffmann's Syndrome

Directory of Open Access Journals (Sweden)

Kang Won Lee

2015-12-01

Full Text Available Hypothyroid myopathy is observed frequently and the resolution of the clinical manifestations of myopathy following thyroid hormone replacement is well known. However, a specific subtype of hypothyroid myopathy, Hoffmann's syndrome, characterized by increased muscular mass (pseudohypertrophy, proximal muscle weakness, muscle stiffness and cramps, is rarely reported. Herein, we describe a 34-year-old male who presented with proximal muscle weakness and non-pitting edema of the lower extremities. He initially visited the neurology department where he was suspected of having polymyositis. Additional laboratory evaluation revealed profound autoimmune hypothyroidism and elevated muscle enzymes including creatine kinase. The patient was started on levothyroxine treatment and, subsequently, clinical symptoms and biochemical parameters resolved with the treatment. The present case highlights that hypothyroidism should be considered in the differential diagnosis of musculoskeletal symptoms even in the absence of overt manifestations of hypothyroidism. To our knowledge, this is the first case reported in Korea.

Thoracic manifestation of tuberculosis; Thorakale Manifestation der Tuberkulose

Energy Technology Data Exchange (ETDEWEB)

Kienzl-Palma, D.; Prosch, H. [Medizinische Universitaet Wien, Abteilung fuer Allgemeine Radiologie und Kinderradiologie, Universitaetsklinik fuer Radiologie und Nuklearmedizin, Wien (Austria)

2016-10-15

Tuberculosis (TB) is a granulomatous disease caused by Mycobacterium tuberculosis and transmission is via an airborne route by droplet infection. In the majority of cases patients have thoracic TB, which most frequently presents with hilar lymphadenopathy and pulmonary manifestation. Due to the rise in incidence of TB in central Europe to be expected over the coming years, it is essential to be acquainted with the radiological manifestations of pulmonary TB, particularly to be able to discriminate active from inactive TB. Due to the use of molecular techniques entailing DNA fingerprinting, the traditional classification of TB in primary and postprimary TB is being challenged. These genetic studies have revealed that variations in the clinical and radiographic appearance of TB are mainly affected by the immune status of the patients. Due to the low prevalence of TB in central Europe and the wide variation of radiological presentations, the diagnosis and therapy of TB is often delayed. In this article, the radiographic manifestations of thoracic TB are summarized and discussed. Together with the medical history and bacteriological tests, chest X-ray imaging and computed tomography (CT) play a major role not only in the detection of TB but also in the follow-up during and after therapy. Chest X-radiographs should be the primary diagnostic method in patients with suspected TB in screening as well as for diagnosis and therapy monitoring. The use of CT is more sensitive than chest radiographs and is frequently performed after chest radiographs to obtain detailed information about subtle parenchymal changes or lymph node manifestation. When active TB is suspected CT should be performed. Tree in bud, lobular consolidations, centrilobular nodules, cavities and ground-glass opacification are typical changes in active TB. (orig.) [German] Tuberkulose (Tbc) ist eine durch Troepfchen uebertragene granulomatoese Infektionserkrankung, die durch das Mycobacterium tuberculosis

Idiopathic Pulmonary Fibrosis: Diagnosis and Clinical Manifestations

Science.gov (United States)

Nakamura, Yutaro; Suda, Takafumi

2015-01-01

Idiopathic pulmonary fibrosis (IPF) is a parenchymal lung disease characterized by progressive interstitial fibrosis. The clinical course of IPF can be unpredictable and may be punctuated by acute exacerbations. Although much progress is being made in unraveling the mechanisms underlying IPF, effective therapy for improving survival remains elusive. Longitudinal disease profiling, especially in terms of clinical manifestations in a large cohort of patients, should lead to proper management of the patients and development of new treatments for IPF. Appropriate multidisciplinary assessment in ongoing registries is required to achieve this. This review summarizes the current status of the diagnosis and clinical manifestations of IPF. PMID:27625576

Global exponential stability of neutral high-order stochastic Hopfield neural networks with Markovian jump parameters and mixed time delays.

Science.gov (United States)

Huang, Haiying; Du, Qiaosheng; Kang, Xibing

2013-11-01

In this paper, a class of neutral high-order stochastic Hopfield neural networks with Markovian jump parameters and mixed time delays is investigated. The jumping parameters are modeled as a continuous-time finite-state Markov chain. At first, the existence of equilibrium point for the addressed neural networks is studied. By utilizing the Lyapunov stability theory, stochastic analysis theory and linear matrix inequality (LMI) technique, new delay-dependent stability criteria are presented in terms of linear matrix inequalities to guarantee the neural networks to be globally exponentially stable in the mean square. Numerical simulations are carried out to illustrate the main results. © 2013 ISA. Published by ISA. All rights reserved.

From a stochastic to a macroscopic approach to brownian motion

International Nuclear Information System (INIS)

Bocquet, L.

1998-01-01

In this lecture, we examine the dynamics of suspensions of mesoscopic (Brownian) particles in a molecular fluid, starting from first principles. We introduce the technique of multiple time-scales to derive the Fokker-Planck equation for a single, or for a set of interacting Brownian particles, starting from the Liouville equation for the full system (Brownian particles and discrete bath). The limitations of the Fokker-Planck equation will then be emphasized. In particular, we shall point out that under ''standard'' experimental conditions, the Fokker-Planck description cannot be correct and that non-Markovian effects are expected. A microscopic description in the true experimental limit confirms this breakdown and leads to a ''generalized'' (non-Markovian and non-local in velocity space) Fokker-Planck equation, which describes the thermalization of the Brownian particle. (author)

Effect of two-qutrit entanglement on quantum speed limit time of a bipartite V-type open system

Energy Technology Data Exchange (ETDEWEB)

Behzadi, N., E-mail: n.behzadi@tabrizu.ac.ir [Research Institute for Fundamental Sciences, University of Tabriz (Iran, Islamic Republic of); Ahansaz, B.; Ektesabi, A.; Faizi, E. [Physics Department, Azarbaijan Shahid Madani University, Tabriz (Iran, Islamic Republic of)

2017-03-15

In the present paper, quantum speed limit (QSL) time of a bipartite V-type three-level atomic system under the effect of two-qutrit entanglement is investigated. Each party interacts with own independent reservoir. By considering two local unitarily equivalent Werner states and the Horodecki PPT state, as initial states, the QSL time is evaluated for each of them in the respective entangled regions. It is counterintuitively observed that the effect of entanglement on the QSL time driven from each of the initial Werner states are completely different when the degree of non-Markovianity is considerable. In addition, it is interesting that the effect of entanglement of the non-equivalent Horodecki state on the calculated QSL time displays an intermediate behavior relative to the cases obtained for the Werner states.

Gastrointestinal Manifestations of Cystic Fibrosis

Science.gov (United States)

2016-01-01

Cystic fibrosis has historically been considered a pulmonary disease, but with the increasing life expectancy of these patients, gastrointestinal manifestations are becoming more important. Furthermore, nutritional status is closely linked to pulmonary function and, thus, overall mortality. This article discusses gastrointestinal manifestations (which involve nutritional, pancreatic, hepatobiliary, and, in particular, gastrointestinal tract issues) of cystic fibrosis as well as management of the disease. In addition, the article discusses studies that have been critical to our understanding of gastrointestinal manifestations of cystic fibrosis. PMID:27330503

Nephrogenic systemic fibrosis: late skin manifestations

DEFF Research Database (Denmark)

Bangsgaard, Nannie; Marckmann, Peter; Rossen, Kristian

2009-01-01

BACKGROUND: Nephrogenic systemic fibrosis (NSF) is a serious disease that occurs in patients with severe renal disease and is believed to be caused by gadolinium-containing contrast agents. A detailed description of the late skin manifestations of NSF is important to help dermatologists...... and nephrologists recognize the disease. OBSERVATIONS: We studied 17 patients with NSF late in the disease. All patients showed epidermal atrophy and hairlessness of the affected regions, primarily the lower legs. Affected areas were symmetrically distributed and hyperpigmented in most cases. Eleven patients showed......: This descriptive case series of patients with NSF gives a detailed clinical picture of the skin manifestations late in the disease. It demonstrates that the clinical picture in the late stage has a varied presentation and that NSF has a significant effect on the quality of life....

Memory effects on stochastic resonance

Science.gov (United States)

Neiman, Alexander; Sung, Wokyung

1996-02-01

We study the phenomenon of stochastic resonance (SR) in a bistable system with internal colored noise. In this situation the system possesses time-dependent memory friction connected with noise via the fluctuation-dissipation theorem, so that in the absence of periodic driving the system approaches the thermodynamic equilibrium state. For this non-Markovian case we find that memory usually suppresses stochastic resonance. However, for a large memory time SR can be enhanced by the memory.

Gaucher disease in children: radiology of non-central nervous system manifestations

International Nuclear Information System (INIS)

McHugh, K.; Olsen, Oe.E.; Vellodi, A.

2004-01-01

The radiological findings in paediatric Gaucher disease (GD) are reviewed and future challenges for radiology are discussed. This overview is based on a literature review and our experience of children with GD in one of two national institutions for paediatric GD in the UK. GD is known to progress more rapidly in childhood. Current imaging is mainly suitable for ascertaining the complications of GD. The UK recommendations for routine radiological surveillance are discussed. With enzyme replacement therapy (ERT), which dramatically modifies the course of the disorder, the challenge for radiology in the future is likely to be assessing treatment efficacy rather than the detection of disease complications. Disease manifestations are likely to change in those on ERT and the most notable recent alteration in the disease profile in childhood is the virtual disappearance of the acute bone crisis in this population

Gaucher disease in children: radiology of non-central nervous system manifestations

Energy Technology Data Exchange (ETDEWEB)

McHugh, K. E-mail: kmchugh@gosh.nhs.uk; Olsen, Oe.E.; Vellodi, A

2004-02-01

The radiological findings in paediatric Gaucher disease (GD) are reviewed and future challenges for radiology are discussed. This overview is based on a literature review and our experience of children with GD in one of two national institutions for paediatric GD in the UK. GD is known to progress more rapidly in childhood. Current imaging is mainly suitable for ascertaining the complications of GD. The UK recommendations for routine radiological surveillance are discussed. With enzyme replacement therapy (ERT), which dramatically modifies the course of the disorder, the challenge for radiology in the future is likely to be assessing treatment efficacy rather than the detection of disease complications. Disease manifestations are likely to change in those on ERT and the most notable recent alteration in the disease profile in childhood is the virtual disappearance of the acute bone crisis in this population.

Actigraphy Detects Greater Intra-Individual Variability During Gait in Non-Manifesting LRRK2 Mutation Carriers.

Science.gov (United States)

van den Heuvel, Lieneke; Lim, Andrew S; Visanji, Naomi P; Huang, Jana; Ghate, Taneera; Mestre, Tiago A; AlDakheel, Amaal; Connolly, Barbara S; Gasca-Salas, Carmen; Kern, Drew S; Jain, Jennifer; Slow, Elizabeth J; Pondal, Margarita; Faust-Socher, Achinoam; Rogaeva, Ekaterina; Tomlinson, George; Lang, Anthony E; Marras, Connie

2018-01-01

With recent advances in the search for disease-modifying therapies for Parkinson's disease (PD) the importance of identifying prodromal markers becomes greater. Non-manifesting LRRK2 mutation carriers (NMC) are at risk for developing PD, and provide a population in which to identify possible markers. The aim of this study was to test the hypothesis that NMC have differences in daily activity, fragmentation of sleep, arm swing asymmetry, and movement variability during walking, detectable by actigraphy, as compared to matched control subjects. Eleven NMC, fourteen PD patients (4 LRRK2-PD, 10 idiopathic PD (iPD)), and twenty-nine controls wore wristbands containing an accelerometer for seven days, and performed a daily walking task. Outcome measures included daily activity, fragmentation of activity, fragmentation of sleep, arm swing asymmetry during walking, and intra-individual variability. Compared to healthy controls, both NMC and LRRK2/iPD showed higher intra-individual variability in activity during walking compared to healthy controls. Individuals with LRRK2-PD/iPD, but not NMC, tend to have lower activity levels, more arm swing asymmetry and less increase of arm swing with transition from slow to faster walking speed compared to healthy controls. Higher intra-individual variability of gait-associated movements might be a useful biomarker of prodromal PD. These results encourage replication in a larger sample and longitudinal analysis is warranted.

Cardiometabolic effects of antidiabetic drugs in non-alcoholic fatty liver disease

DEFF Research Database (Denmark)

Rix, Iben; Steen Pedersen, Julie; Storgaard, Heidi

2018-01-01

PURPOSE: Non-alcoholic fatty liver disease (NAFLD) affects about 25% of the population worldwide. NAFLD may be viewed as the hepatological manifestation of metabolic syndrome. Patients with metabolic syndrome due to diabetes or obesity have an increased risk of cardiovascular disease....... This narrative review describes cardiometabolic effects of antidiabetic drugs in NAFLD. METHODS: We conducted a systematic search in PubMed and manually scanned bibliographies in trial databases and reference lists in relevant articles. RESULTS: Heart disease is the leading cause of death in NAFLD. Conversely......, NAFLD is an independent cardiovascular risk factor in patients suffering from metabolic syndrome. NAFLD is associated with markers of atherosclerosis, and patients have increased risk of ischaemic heart disease. Additionally, patients with NAFLD have increased risk of cardiac dysfunction and heart...

Estimation of temperature in micromaser-type systems

Science.gov (United States)

Farajollahi, B.; Jafarzadeh, M.; Rangani Jahromi, H.; Amniat-Talab, M.

2018-06-01

We address the estimation of the number of photons and temperature in a micromaser-type system with Fock state and thermal fields. We analyze the behavior of the quantum Fisher information (QFI) for both fields. In particular, we show that in the Fock state field model, the QFI for non-entangled initial state of the atoms increases monotonously with time, while for entangled initial state of the atoms, it shows oscillatory behavior, leading to non-Markovian dynamics. Moreover, it is observed that the QFI, entropy of entanglement and fidelity have collapse and revival behavior. Focusing on each period that the collapses and revivals occur, we see that the optimal points of the QFI and entanglement coincide. In addition, when one of the subsystems evolved state fidelity becomes maximum, the QFI also achieves its maximum. We also address the evolved fidelity versus the initial state as a good witness of non-Markovianity. Moreover, we interestingly find that the entropy of the composite system can be used as a witness of non-Markovian evolution of the subsystems. For the thermal field model, we similarly investigate the relation among the QFI associated with the temperature, von Neumann entropy, and fidelity. In particular, it is found that at the instants when the maximum values of the QFI are achieved, the entanglement between the two-qubit system and the environment is maximized while the entanglement between the probe and its environment is minimized. Moreover, we show that the thermometry may lead to optimal estimation of practical temperatures. Besides, extending our computation to the two-qubit system, we find that using a two-qubit probe generally leads to more effective estimation than the one-qubit scenario. Finally, we show that initial state entanglement plays a key role in the advent of non-Markovianity and determination of its strength in the composite system and its subsystems.

Generalized Langevin dynamics of a nanoparticle using a finite element approach: Thermostating with correlated noise

Science.gov (United States)

Uma, B.; Swaminathan, T. N.; Ayyaswamy, P. S.; Eckmann, D. M.; Radhakrishnan, R.

2011-09-01

A direct numerical simulation (DNS) procedure is employed to study the thermal motion of a nanoparticle in an incompressible Newtonian stationary fluid medium with the generalized Langevin approach. We consider both the Markovian (white noise) and non-Markovian (Ornstein-Uhlenbeck noise and Mittag-Leffler noise) processes. Initial locations of the particle are at various distances from the bounding wall to delineate wall effects. At thermal equilibrium, the numerical results are validated by comparing the calculated translational and rotational temperatures of the particle with those obtained from the equipartition theorem. The nature of the hydrodynamic interactions is verified by comparing the velocity autocorrelation functions and mean square displacements with analytical results. Numerical predictions of wall interactions with the particle in terms of mean square displacements are compared with analytical results. In the non-Markovian Langevin approach, an appropriate choice of colored noise is required to satisfy the power-law decay in the velocity autocorrelation function at long times. The results obtained by using non-Markovian Mittag-Leffler noise simultaneously satisfy the equipartition theorem and the long-time behavior of the hydrodynamic correlations for a range of memory correlation times. The Ornstein-Uhlenbeck process does not provide the appropriate hydrodynamic correlations. Comparing our DNS results to the solution of an one-dimensional generalized Langevin equation, it is observed that where the thermostat adheres to the equipartition theorem, the characteristic memory time in the noise is consistent with the inherent time scale of the memory kernel. The performance of the thermostat with respect to equilibrium and dynamic properties for various noise schemes is discussed.

Cutaneous manifestations of systemic lupus erythematosus in a tertiary referral center

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Kole Alakes

2009-01-01

Full Text Available Background : Systemic lupus erythematosus (SLE is an autoimmune disease with multiorgan involvement. The skin is the second most commonly affected organ. SLE with skin lesions can produce considerable morbidity resulting from painful skin lesions, alopecia, disfigurement, etc. Skin lesions in patients with lupus may be specific (LE specific or may be non specific (LE non specific. Acute cutaneous LE (Lupus specific has a strong association with systemic disease and non-specific skin lesions always indicate disease activity for which patients present to rheumatologists and internists. Therefore, a thorough understanding of the cutaneous manifestations of SLE is essential for most efficient management. Aims: The aims of this study were to evaluate the patterns and prevalence of skin lesions in patients with SLE and to assess the relationship between skin lesions and other systemic involvement. Materials and Methods: At the Department of Rheumatology and Clinical Immunology, IPGME&R in Kolkata, 150 patients with SLE fulfilling the clinical and laboratory criteria of the American Rheumatology Association (updated 1982 were examined and followed-up for cutaneous manifestations between January 2002 and January 2007. Results: Skin lesions were important clinical features. About 45 patients (30% presented with skin lesions although all patients had skin lesions during the follow-up period. Skin changes noted were as follows: Lupus specific lesions: malar rash in 120 patients (80%, photosensitive dermatitis in 75 patients (50%, generalized maculopapular rash in 40 patients (26.67%, discoid rash in 30 patients (20%, subacute cutaneous lupus erythematosus (SCLE in 5 patients (3.34%, lupus profundus in 5 patients (3.34%. The lupus non-specific lesions were non-scarring alopecia in 130 patients (86.67%, oral ulcers in 85 patients (56.67%, vasculitic lesions in 50 patients (33.34%, bullous lesions in 15 patients (10%, Raynaud′s phenomenon in 10 patients (6

Animal vocal sequences: not the Markov chains we thought they were.

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Kershenbaum, Arik; Bowles, Ann E; Freeberg, Todd M; Jin, Dezhe Z; Lameira, Adriano R; Bohn, Kirsten

2014-10-07

Many animals produce vocal sequences that appear complex. Most researchers assume that these sequences are well characterized as Markov chains (i.e. that the probability of a particular vocal element can be calculated from the history of only a finite number of preceding elements). However, this assumption has never been explicitly tested. Furthermore, it is unclear how language could evolve in a single step from a Markovian origin, as is frequently assumed, as no intermediate forms have been found between animal communication and human language. Here, we assess whether animal taxa produce vocal sequences that are better described by Markov chains, or by non-Markovian dynamics such as the 'renewal process' (RP), characterized by a strong tendency to repeat elements. We examined vocal sequences of seven taxa: Bengalese finches Lonchura striata domestica, Carolina chickadees Poecile carolinensis, free-tailed bats Tadarida brasiliensis, rock hyraxes Procavia capensis, pilot whales Globicephala macrorhynchus, killer whales Orcinus orca and orangutans Pongo spp. The vocal systems of most of these species are more consistent with a non-Markovian RP than with the Markovian models traditionally assumed. Our data suggest that non-Markovian vocal sequences may be more common than Markov sequences, which must be taken into account when evaluating alternative hypotheses for the evolution of signalling complexity, and perhaps human language origins. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Colored thermal noise driven dynamical system in the presence and absence of non-equilibrium constraint: time dependence of information entropy flux and entropy production

International Nuclear Information System (INIS)

Goswami, Gurupada; Mukherjee, Biswajit; Bag, Bidhan Chandra

2005-01-01

We have studied the relaxation of non-Markovian and thermodynamically closed system both in the absence and presence of non-equilibrium constraint in terms of the information entropy flux and entropy production based on the Fokker-Planck and the entropy balance equations. Our calculation shows how the relaxation time depends on noise correlation time. It also considers how the non-equilibrium constraint is affected by system parameters such as noise correlation time, strength of dissipation and frequency of dynamical system. The interplay of non-equilibrium constraint, frictional memory kernel, noise correlation time and frequency of dynamical system reveals the extremum nature of the entropy production

Colored thermal noise driven dynamical system in the presence and absence of non-equilibrium constraint: time dependence of information entropy flux and entropy production

Science.gov (United States)

Goswami, Gurupada; Mukherjee, Biswajit; Bag, Bidhan Chandra

2005-06-01

We have studied the relaxation of non-Markovian and thermodynamically closed system both in the absence and presence of non-equilibrium constraint in terms of the information entropy flux and entropy production based on the Fokker-Planck and the entropy balance equations. Our calculation shows how the relaxation time depends on noise correlation time. It also considers how the non-equilibrium constraint is affected by system parameters such as noise correlation time, strength of dissipation and frequency of dynamical system. The interplay of non-equilibrium constraint, frictional memory kernel, noise correlation time and frequency of dynamical system reveals the extremum nature of the entropy production.

Consensus of multiple autonomous underwater vehicles with double independent Markovian switching topologies and timevarying delays

International Nuclear Information System (INIS)

Yan Zhe-Ping; Liu Yi-Bo; Zhou Jia-Jia; Zhang Wei; Wang Lu

2017-01-01

A new method in which the consensus algorithm is used to solve the coordinate control problems of leaderless multiple autonomous underwater vehicles (multi-AUVs) with double independent Markovian switching communication topologies and time-varying delays among the underwater sensors is investigated. This is accomplished by first dividing the communication topology into two different switching parts, i.e., velocity and position, to reduce the data capacity per data package sent between the multi-AUVs in the ocean. Then, the state feedback linearization is used to simplify and rewrite the complex nonlinear and coupled mathematical model of the AUVs into a double-integrator dynamic model. Consequently, coordinate control of the multi-AUVs is regarded as an approximating consensus problem with various time-varying delays and velocity and position topologies. Considering these factors, sufficient conditions of consensus control are proposed and analyzed and the stability of the multi-AUVs is proven by Lyapunov–Krasovskii theorem. Finally, simulation results that validate the theoretical results are presented. (paper)

Radiographic manifestations of hypochondroplasia

Energy Technology Data Exchange (ETDEWEB)

Heselson, N G; Cremin, B J [Groote Schuur Hospital, Cape Town (South Africa); Beighton, P

1979-01-01

Hypochrondroplasia is an inherited skeletal dysplasia that resembles achondroplasia in mild degree. Radiographic manifestations encountered in 12 affected individuals in South Africa include slight shortening of all segments of the tubular bones, moderate caudal diminution of the lumbar interpedicular distances, increased lumbar lordosis with cacral tilt and distal prolongation of the fibular. Hypochondroplasia can be distinguished from other osteochondrodystrophies such as achondroplasia, pseudo-achondroplasia and metaphyseal chondroplasia by the recognition of it clinical and radiographic manifestations.

Intrathoracic manifestations of Rosai-Dorfman disease.

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Cartin-Ceba, Rodrigo; Golbin, Jason M; Yi, Eunhee S; Prakash, Udaya B S; Vassallo, Robert

2010-09-01

Rosai-Dorfman Disease (RDD), also known as Sinus Histiocytosis with Massive Lymphadenopathy (SHML), is a rare monocyte/macrophage proliferative disorder of varied biological behavior. Although cutaneous and lymph node involvement are relatively well-described, intrathoracic manifestations of RDD have only occasionally been reported. We conducted a retrospective computer-assisted search of the Mayo Clinic record from 1976 to 2005 for patients with histopathologic evidence of RDD on organ biopsy. Clinical characteristics were abstracted from charts and thoracic manifestations recorded. Survival was estimated using the national social security database. A total of 21 patients were diagnosed with RDD over a period of 30 years; 9 had intrathoracic manifestations (43%). Main pulmonary symptoms included dyspnea and cough. Age at the time of diagnosis, gender, race, smoking history, mortality and time of survival after diagnosis were no different between RDD patients with and without intrathoracic manifestations. The most common radiographic thoracic manifestation was mediastinal lymphadenopathy (6 patients). Cystic change, interstitial lung disease, and airway disease were radiographically evident in 4 patients. Seven patients were treated at some point in the course of their disease, most commonly with oral corticosteroids. At the time of last follow-up 87% were alive, with a median (IQR) time interval since diagnosis of 8 years (4-9.7). Intrathoracic manifestations of RDD are relatively common and include mediastinal lymphadenopathy, airway disease, pleural effusion, cystic and interstitial lung disease. Although limited in size, this series suggests the prognosis of patients with RDD and intrathoracic manifestations is relatively good.

Imaging of systemic lupus erythematosus. Part I: CNS, cardiovascular, and thoracic manifestations

International Nuclear Information System (INIS)

Goh, Y.P.; Naidoo, P.; Ngian, G.S.

2013-01-01

Systemic lupus erythematosus (SLE) is a chronic, multisystem autoimmune disease that has a relapsing and remitting course. It has a wide range of non-specific symptoms with various organ manifestations. In 1982, the American College of Rheumatology (ACR) published the revised criteria for the classification of SLE. The diagnosis of SLE may be made if four or more of the 11 ACR criteria are present, either serially or simultaneously, during any interval of observation. Whilst the diagnosis of SLE is based on clinical and laboratory features, with no universally accepted radiological diagnostic criteria, imaging is nonetheless useful for diagnosing specific organ manifestations, monitoring disease progression, and identifying complications secondary to immunosuppressive therapy. In this review, we describe the spectrum of radiological findings of SLE in various organ systems and compile a list of organ manifestations including the most frequently occurring diseases as well as the rare but not-to-be-missed diseases. This review aims to serve as a concise reference tool in an endeavour to assist clinicians and radiologists in the diagnosis and monitoring of this disease. This pictorial review presents the various radiological findings of CNS, cardiovascular and thoracic manifestation of SLE. The gastrointestinal, renal and musculoskeletal systems will be covered in part II.

Temporal profile of pain and other sensory manifestations in Guillain-Barre′ syndrome during ten days of hospitalization

OpenAIRE

K Karkare; Arun B Taly; Sanjib Sinha; S Rao

2011-01-01

Background: Focused studies on sensory manifestations, especially pain and paresthesia in Guillain-Barre′ (GB) syndrome are few and far between. Aim: To study the sensory manifestations in GB syndrome during 10 days of hospitalization with clinico-electrophysiological correlation. Materials and Methods: The study included 60 non-consecutive patients with GB syndrome, fulfilling National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) criteria for GB syndrome. Data es...

Manifestation of transient effects in fission induced by relativistic heavy-ion collisions

Energy Technology Data Exchange (ETDEWEB)

Jurado, B.; Schmitt, C.; Schmidt, K.H.; Benlliure, J. [Universidad de Santiago de Compostela (Spain); Junghans, A.R. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (Germany)

2004-03-01

We examine the manifestation of transient effects in fission by analysing experimental data where fission is induced by peripheral heavy-ion collisions at relativistic energies. Available total nuclear fission cross sections of {sup 238}U at1.A GeV on gold and uranium targets are compared with a nuclear-reaction code, where transient effects in fission are modelled using different approximations to the numerical time-dependent fission-decay width: a new analytical description based on the solution of the Fokker-Planck equation and two widely used but less realistic descriptions, a step function and an exponential-like function. The experimental data are only reproduced when transient effects are considered. The deduced value of the dissipation strength {beta} depends strongly on the approximation applied for the time-dependent fission-decay width and is estimated to be of the order of 2 x 10{sup 21} s{sup -1}. A careful analysis sheds severe doubts on the use of the exponential-like in-growth function largely used in the past. Finally, we discuss which should be the characteristics of experimental observables to be most sensitive to transient effects in fission. (orig.)

Cutaneous manifestations of primary immunodeficiency

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Safa Abdelhakim

2017-01-01

Full Text Available Primary immunodeficiency diseases (PIDs are a group of rare, chronic disorders with deficient or malfunctioning immune system. It commonly affects the hematopoietic system, with skin the second most affected organ. Skin involvement is observed in half of pediatric PID cases and often precedes the final diagnosis. Skin infections and eczemas are the two most common manifestations in PID.[1] Skin manifestations associated with PIDs can be of infectious and noninfectious causes. Common noninfectious causes are eczema, erythroderma, cutaneous granulomas, dysplasia, vasculitis, and telangiectasia. It is important to be aware of skin manifestations in pediatric patients as early detection of PID may aid in the management of serious immunologic conditions and prevent associated morbidity and mortality.

Season of birth, clinical manifestations and Dexamethasone Suppression Test in unipolar major depression

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Kaprinis George S

2007-08-01

Full Text Available Abstract Background Reports in the literature suggest that the season of birth might constitute a risk factor for the development of a major psychiatric disorder, possibly because of the effect environmental factors have during the second trimester of gestation. The aim of the current paper was to study the possible relationship of the season of birth and current clinical symptoms in unipolar major depression. Methods The study sample included 45 DSM-IV major depressive patients and 90 matched controls. The SCAN v. 2.0, Hamilton Depression Rating Scale (HDRS and Hamilton Anxiety Scale (HAS were used to assess symptomatology, and the 1 mg Dexamethasone Suppression Test (DST was used to subcategorize patients. Results Depressed patients as a whole did not show differences in birth season from controls. However, those patients born during the spring manifested higher HDRS while those born during the summer manifested the lowest HAS scores. DST non-suppressors were almost exclusively (90% likely to be born during autumn and winter. No effect from the season of birth was found concerning the current severity of suicidal ideation or attempts. Discussion The current study is the first in this area of research using modern and rigid diagnostic methodology and a biological marker (DST to categorize patients. Its disadvantages are the lack of data concerning DST in controls and a relatively small size of patient sample. The results confirm the effect of seasonality of birth on patients suffering from specific types of depression.

Environment-assisted Quantum Critical Effect for Excitation Energy Transfer in a LH2-type Trimer

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Xu, Lan; Xu, Bo

2015-10-01

In this article, we are investigating excitation energy transfer (EET) in a basic unit cell of light-harvesting complex II (LH2), named a LH2-type trimer. Calculation of energy transfer efficiency (ETE) in the framework of non-Markovian environment is also implemented. With these achievements, we theoretically predict the environment-assisted quantum critical effect, where ETE exhibits a sudden change at the critical point of quantum phase transition (QPT) for the LH2-type trimer. It is found that highly efficient EET with nearly unit efficiency may occur in the vicinity of the critical point of QPT.

Age-dependent decay in the landscape

International Nuclear Information System (INIS)

Winitzki, Sergei

2008-01-01

The picture of the 'multiverse' arising in diverse cosmological scenarios involves transitions between metastable vacuum states. It was pointed out by Krauss and Dent that the transition rates decrease at very late times, leading to a dependence of the transition probability between vacua on the age of each vacuum region. I investigate the implications of this non-Markovian, age-dependent decay on the global structure of the spacetime in landscape scenarios. I show that the fractal dimension of the eternally inflating domain is precisely equal to 3, instead of being slightly below 3, which is the case in scenarios with purely Markovian, age-independent decay. I develop a complete description of a non-Markovian landscape in terms of a nonlocal master equation. Using this description I demonstrate by an explicit calculation that, under some technical assumptions about the landscape, the probabilistic predictions of our position in the landscape are essentially unchanged, regardless of the measure used to extract these predictions. I briefly discuss the physical plausibility of realizing non-Markovian vacuum decay in cosmology in view of the possible decoherence of the metastable quantum state.

The skin as a window to the blood: Cutaneous manifestations of myeloid malignancies.

Science.gov (United States)

Li, Alvin W; Yin, Emily S; Stahl, Maximilian; Kim, Tae Kon; Panse, Gauri; Zeidan, Amer M; Leventhal, Jonathan S

2017-11-01

Cutaneous manifestations of myeloid malignancies are common and have a broad range of presentations. These skin findings are classified as specific, due to direct infiltration by malignant hematopoietic cells, or non-specific. Early recognition and diagnosis can have significant clinical implications, as skin manifestations may be the first indication of underlying hematologic malignancy, can reflect the immune status and stage of disease, and cutaneous reactions may occur from conventional and targeted agents used to treat myeloid disease. In addition, infections with cutaneous involvement are common in immunocompromised patients with myeloid disease. Given the varying presentations, dermatologic findings associated with myeloid malignancies can pose diagnostic challenges for hematologists and dermatologists. In this clinical review intended for the practicing hematologist/oncologist, we discuss the presentation, diagnosis, treatment, and prognostic value of the most common cutaneous manifestations associated with myeloid malignancies using illustrative macro- and microscopic figures and with a special emphasis on practical considerations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tripartite nonlocality for an open Dirac system in the background of Schwarzschild space-time

Science.gov (United States)

Ding, Zhi-Yong; Shi, Jia-Dong; Wu, Tao; He, Juan

2017-12-01

In this paper, the behavior of the tripartite nonlocality for a Dirac system in the background of Schwarzschild space-time is studied. It is shown that the nonlocality of the ultimate physical accessible state always decreases as the Hawking effect increases monotonically, which is independent of the number of particles located near the event horizon. Besides, the more particles there are located near the event horizon, the more difficult the violation of the Svetlichny inequality becomes. Furthermore, we investigate the property of these particles suffering from a non-Markovian environment, and derive that the nonlocality decreases quickly with the increasing decoherence time accompanied by damping revivals. To preserve tripartite nonlocality in the non-Markovian environment, we propose a scheme by means of prior weak measurement and post measurement reversal. It is worth noticing that the effect is better for larger measurement strengths, while it induces smaller success probability.

HIV-related stigma and psychological distress: the harmful effects of specific stigma manifestations in various social settings.

Science.gov (United States)

Stutterheim, Sarah E; Pryor, John B; Bos, Arjan E R; Hoogendijk, Robert; Muris, Peter; Schaalma, Herman P

2009-11-13

Recent research has shown that experiences of stigmatization have an adverse impact on the psychological well being of people living with HIV/AIDS (PLWHA). Most studies investigating this relationship employ an aggregate measure of stigma. Although this approach provides useful information about the psychological implications of HIV-related stigma in general, it neglects to acknowledge the possibility that some manifestations in specific settings may be psychologically more detrimental than others. The present study examines which specific stigma experiences are most strongly related to psychological distress across a number of social settings. A cross-sectional survey was administered to 667 PLWHA in the Netherlands. We examined participants' experiences of 11 manifestations of HIV-related stigma in six social settings. Linear regression analyses were conducted to determine which setting-specific manifestations best predict psychological distress after controlling for marital status, education and health status. Three manifestations in family settings, namely receiving advice to conceal one's status, being avoided and being treated with exaggerated kindness, and one manifestation in healthcare settings, namely awkward social interaction, best predicted psychological distress in PLWHA. Manifestations of HIV-related stigma vary according to setting. Certain manifestations in specific social settings impact the psychological well being of PLWHA more than others. In this study, certain experiences of stigmatization with PLWHA's families and in healthcare settings were more strongly related to psychological distress than experiences occurring in other social settings. These findings suggest that stigma reduction interventions focusing on these influential settings may benefit the psychological well being of PLWHA.

[Clinical, endoscopic and morphological manifestations of oesophageal lesion in systemic scleroderma].

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Karateev, A E; Movsiian, A E; Anan'eva, M M; Radenska-Lopovok, S G

2014-01-01

Oesophageal lesion is the commonest visceral manifestation of systemic scleroderma (SSD) affecting the quality of life and fraught with serious complications. The aim of this study was to evaluate clinical, endoscopic andmorphological manifestations of oesophageal lesion in systemic scleroderma and its relationships with other clinical symptoms and pharmacotherapy of the disease. 479 patients with SSD (93.7% women, 6.3% men, mean age 48.7 +/- 19.2 yr). All of them underwent EGDS in 2005-2010. 123 patients were examined for the detection of Barrett's oesophagus (BO), total screening regardless of complaints was conducted in 2010. Control group included 1018 age and sex-matched patients with RA who underwent EGDS in 2008-2009. Oesophageal lesions occurred much more frequently in SSD than in RA. Oesophageal symptoms were documented in 70.0 and 29.9% cases, non-erosive oesopahgitis in 28.8 and 1.5%, erosive esophagitis in 22.5 and 2.2% ulcers in 0.8 and 0% (p < 0.001). BO manifested as intestinal metaplasia (histological study of mucosal biopsy) was found in 30 SSD patients (4.2%). Screening revealed BO in 8.9% of the patients. The development of erosive oesophagitis was unrelated to the age of the patients, duration of the disease and its form (localized or diffusive), lung pathology or Sjogren's syndrome. Cytotoxic medicines significantly increased the frequency of erosive oesophagitis, it tended to increase under effect of NSAID and low doses of aspirin. Long-term intake of PPI did not reduce the risk of oesophagitis and BO. Half of the patients with SSD have oesophagitis. Over 20% of them suffer its complications (erosion and ulcers) and 9% have BO. All such patients need endoscopic study ofoesophagus regardless of clinical symptoms.

Pulmonary manifestations of leptospirosis

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Sameer Gulati

2012-01-01

Full Text Available Leptospirosis has a spectrum of presentation which ranges from mild disease to a severe form comprising of jaundice and renal failure. Involvement of the lung can vary from subtle clinical features to deadly pulmonary hemorrhage and acute respiratory distress syndrome. Of late, it has been identified that leptospirosis can present atypically with predominant pulmonary manifestations. This can delay diagnosis making and hence optimum treatment. The purpose of this review is to bring together all the reported pulmonary manifestations of leptospirosis and the recent trends in the management.

Thermodynamics in 'Manifest Reality'

International Nuclear Information System (INIS)

Hankey, Alex

2010-01-01

D'Espagnat's proof that the universe is not a 'strongly objective reality' demands that all physical processes are reconsidered in that light. D'Espagnat suggests a 'Veiled Reality' as a suitable alternative. The most economical way to achieve that is to demand that 'information production' at a quantum level creates the basis for self-consistent perception of a world of macroscopic, 'manifest' entities, as opposed to self-existent objects. Such a 'manifest reality' fulfils both Wheeler's attempt at an 'IT-from-BIT' programme, and Zeilinger's suggestion that 'information is primary'.

Psychological effects of (non)employment: A cross-national comparison of the United States and Japan.

Science.gov (United States)

Gnambs, Timo; Stiglbauer, Barbara; Selenko, Eva

2015-12-01

The involuntary loss of employment has been shown to deteriorate subjective well-being. Adopting a cross-cultural perspective on Jahoda's (1982) deprivation model this study examines several latent and manifest benefits of work that were expected to mediate the effects of employment status on well-being. It was hypothesized that in more collectivistic societies the decline in subjective well-being would be a consequence of a diminished sense of collective purpose for the non-employed, whereas in individualistic societies the crucial factors would be a loss of social status and financial benefits. The findings from two representative national surveys conducted in the United States (N = 1,093) and Japan (N = 647) provided partial support for these hypotheses. Cultural differences moderated the effects of employment status on the benefits of work. As a consequence, different processes mediated the decline in well-being for the non-employed in the two countries. These results are embedded within the wider discourse on culture and its effect on unemployment. © 2015 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Hematologic manifestations of Crohn's disease: two clinical cases

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O. V. Taratina

2017-01-01

Full Text Available Inflammatory bowel diseases (IBD are commonly associated with extraintestinal manifestations, hematological disorders being the most special among them. In some cases, they dominate the clinical picture masking the intestinal manifestations of the underlying disease. Aplastic anemia is an extremely rare extraintestinal IBD manifestation. There are only two clinical cases of aplastic anemia associated with ulcerative colitis and non with Crohn's disease reported in the literature. Combination of Crohn's disease and В₁₂-deficient anemia is more prevalent, but is seen usually only after more than 20 cm of the ileus has been resected. The first clinical case presented in this paper is a  combination of severe fistula-forming Crohn's disease with a constriction in the terminal part of the ileus and profound pancytopenia as an outcome of aplastic anemia. This profound pancytopenia is associated with an extremely high risk of life-threatening complications both of surgical treatment, as well as of several chemotherapeutic agents, which made the management of this patient difficult. The second clinical case demonstrates the manifestation of Crohn's disease as ileocolitis starting from the symptoms of cobalamin deficiency: severe В₁₂-deficient anemia, funicular myelosis and sensory ataxia, with blunted intestinal symptoms. This made the initial diagnosis and timely treatment difficult. Replacement therapy with cobalamin injections and treatment with glucocorticoids and antibacterials led to endoscopically confirmed remission of Crohn's disease and normalization of hematological parameters, with persistent polyneuropathy. Thus, management of patients with Crohn's disease should be multidisciplinary. In the case of anemia, leucopenia and/or thrombocytopenia in IBD patients it is necessary to exclude potential myelodysplasia and bone marrow aplasia. In the event of megaloblastic anemia and/or progressive polyneuropathy one should bear in mind

Thermodiffusion as a close-to-interface effect that matters in non-isothermal (dis)orderly protein aggregations

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Gadomski, A., E-mail: agad@utp.edu.pl; Kruszewska, N., E-mail: nkruszewska@utp.edu.pl

2014-08-01

The goal of this discussion letter is to argue how and why an inherent nanoscale thermodiffusion (Soret-type) effect can be relevant in (dis)orderly protein aggregation. We propose a model in which the aggregation of proteins, in the presence of temperature gradient, is described in terms of Smoluchowski dynamics in the phase space of nuclei sizes. The Soret coefficient of the aggregation is proportional to the variations of the aggregation free energy over temperature. The free energy is related to the (interface) boundary condition of the system. When boundary condition is of equilibrium Gibbs–Thomson type, with a well-stated surface tension of the nucleus, to the system can be assigned a negative Soret effect. On the contrary, when a non-equilibrium perturbing (salting-out) term enters the boundary condition, a positive Soret effect may manifest. A zero-value Soret regime is expected to occur in between, yielding very soft (“fragile”) non-Kossel protein-type crystals. - Highlights: • Comprehension for non-isothermal formation of (dis)orderly protein aggregation. • Classification of temperature-sensitive morphologies in colloid-type aggregation. • Morphologies split into near-equilibrium and nonequilibrium structural outcomes. • Classification on mesoscopic nonequilibrium thermodynamics near local equilibrium.

The analysis of the derivation principles of kinetic equations based on exactly solvable models of the bulk reaction A + B → Product

International Nuclear Information System (INIS)

Kipriyanov, A.A.; Doktorov, A.B.

2005-01-01

We have considered two many-particle models of the irreversible reaction A + B → Product for which closed kinetic equations for the mean concentration N A (t) of A species can be exactly obtained. These equations are identically recast into a unified form of integro-differential equation of general kinetic theory. It is shown that the memory functions for both models under consideration can be represented as a sum of the Markovian and non-Markovian parts. It is essential that the Markovian part of the Laplace transform of any kernel can be obtained using the Laplace transform of the kernel itself, and is the root of the non-Markovian part of the Laplace transform of the kernel. The properties established allowed us to perform correct approximation of the memory functions at small concentrations [B] of B species and derive the binary non-Markovian integro-differential equation. Within the binary theory accuracy this equation has been rewritten in a regular frame of a familiar rate equation satisfying general principles of binary kinetic equations. Thus using particular exactly solvable many-particle models, we have reproduced the most essential steps of the known general way for the derivation of the binary kinetic equation avoiding the sophisticated many-particle technique and the corresponding approximations. Besides, the results obtained can serve as an additional evidence of the approximations made in a general many-particle approach to the derivation of the binary kinetic equation

Description of quantum-mechanical motion by using the formalism of non-Markov stochastic process

International Nuclear Information System (INIS)

Skorobogatov, G.A.; Svertilov, S.I.

1999-01-01

The principle possibilities of mathematical modeling of quantum mechanical motion by the theory of a real stochastic processes is considered. The set of equations corresponding to the simplest case of a two-level system undergoing transitions under the influence of electromagnetic field are obtained. It is shown that quantum-mechanical processes are purely discrete processes of non-Markovian type. They are continuous processes in the space of probability amplitudes and posses the properties of quantum Markovity. The formulation of quantum mechanics in terms of the theory of stochastic processes is necessary for its generalization on small space-time intervals [ru

Facial diplegia: etiology, clinical manifestations, and diagnostic evaluation

Directory of Open Access Journals (Sweden)

Sefer Varol

2015-12-01

Full Text Available ABSTRACT Objective Facial diplegia (FD is a rare neurological manifestation with diverse causes. This article aims to systematically evaluate the etiology, diagnostic evaluation and treatment of FD. Method The study was performed retrospectively and included 17 patients with a diagnosis of FD. Results Patients were diagnosed with Guillain-Barré syndrome (GBS (11, Bickerstaff’s brainstem encephalitis (1, neurosarcoidosis (1, non-Hodgkin’s Lymphoma (1, tuberculous meningitis (1 herpes simplex reactivation (1 and idiopathic (1. In addition, two patients had developed FD during pregnancy. Conclusion Facial diplegia is an ominous symptom with widely varying causes that requires careful investigation.

Oral Manifestations in Pediatric Patients with Coeliac Disease - A Review Article.

Science.gov (United States)

Macho, Viviana Marisa Pereira; Coelho, Ana Sofia; Veloso E Silva, Diana Maria; de Andrade, David José Casimiro

2017-01-01

Coeliac disease is a chronic enteropathy that remains a challenge for the clinician, due to its atypical manifestations and etiopathogenic complexity. This article intends to describe the oral characteristics of Coeliac Disease in children in order to facilitate their management in the dental office. A review of the literature was performed electronically in PubMed (PubMed Central, and MEDLINE) for articles published in English from 2000 to April of 2017. The article is also based on the authors' clinical experience with children with coeliac disease. The searched keywords were "coeliac disease ","oral manifestations ", "dental enamel defects", "recurrent aphthous stomatitis" and "oral aphthous ulcers". There are some oral manifestations which are strictly related to coeliac disease: dental enamel defects, recurrent aphthous stomatitis, delayed tooth eruption, multiple caries, angular cheilitis, atrophic glossitis, dry mouth and burning tongue. The complete knowledge of the oral manifestations of coeliac disease can trigger an effective change in the quality of life of the patients with this disease.

Auger Processes Mediating the Nonresonant Optical Emission from a Semiconductor Quantum Dot Embedded Inside an Optical Cavity

DEFF Research Database (Denmark)

Settnes, Mikkel; Nielsen, Per Kær; Lund, Anders Mølbjerg

2013-01-01

perform microscopic calculations of the effect treating the wetting layer as a non-Markovian reservoir interacting with the coupled quantum dot-cavity system through Coulomb interactions. Experimentally, cavity feeding has been observed in the asymmetric detuning range of -10 to +45 meV. We show...

Nonlocal transport in the presence of transport barriers

Science.gov (United States)

Del-Castillo-Negrete, D.

2013-10-01

There is experimental, numerical, and theoretical evidence that transport in plasmas can, under certain circumstances, depart from the standard local, diffusive description. Examples include fast pulse propagation phenomena in perturbative experiments, non-diffusive scaling in L-mode plasmas, and non-Gaussian statistics of fluctuations. From the theoretical perspective, non-diffusive transport descriptions follow from the relaxation of the restrictive assumptions (locality, scale separation, and Gaussian/Markovian statistics) at the foundation of diffusive models. We discuss an alternative class of models able to capture some of the observed non-diffusive transport phenomenology. The models are based on a class of nonlocal, integro-differential operators that provide a unifying framework to describe non- Fickian scale-free transport, and non-Markovian (memory) effects. We study the interplay between nonlocality and internal transport barriers (ITBs) in perturbative transport including cold edge pulses and power modulation. Of particular interest in the nonlocal ``tunnelling'' of perturbations through ITBs. Also, flux-gradient diagrams are discussed as diagnostics to detect nonlocal transport processes in numerical simulations and experiments. Work supported by the US Department of Energy.

Antiphospholipid antibody: laboratory, pathogenesis and clinical manifestations

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T. Ziglioli

2011-06-01

Full Text Available Antiphospholipid antibodies (aPL represent a heterogeneous group of antibodies that recognize various antigenic targets including beta2 glycoprotein I (β2GPI, prothrombin (PT, activated protein C, tissue plasminogen activator, plasmin and annexin A2. The most commonly used tests to detect aPL are: lupus anticoagulant (LAC, a functional coagulation assay, anticardiolipin antibody (aCL and anti-β2GPI antibody (anti-β2GPI, which are enzyme-linked immunoassay (ELISA. Clinically aPL are associated with thrombosis and/or with pregnancy morbidity. Apparently aPL alone are unable to induce thrombotic manifestations, but they increase the risk of vascular events that can occur in the presence of another thrombophilic condition; on the other hand obstetrical manifestations were shown to be associated not only to thrombosis but mainly to a direct antibody effect on the trophoblast.

Altered brain mechanisms of emotion processing in pre-manifest Huntington's disease.

Science.gov (United States)

Novak, Marianne J U; Warren, Jason D; Henley, Susie M D; Draganski, Bogdan; Frackowiak, Richard S; Tabrizi, Sarah J

2012-04-01

, right pallidum, right thalamus, cerebellum, middle frontal, middle occipital, right superior and left inferior temporal gyri, and left superior parietal lobule. The modulated happiness network included postcentral gyri, left caudate, right cingulate cortex, right superior and inferior parietal lobules, and right superior frontal, middle temporal, middle occipital and precentral gyri. These effects were not driven merely by striatal dysfunction. We did not find equivalent associations between brain structure and emotion recognition, and the pre-manifest Huntington's disease cohort did not have a behavioural deficit in out-of-scanner emotion recognition relative to controls. In addition, we found increased neural activity in the pre-manifest subjects in response to all three emotions in frontal regions, predominantly in the middle frontal gyri. Overall, these findings suggest that pathophysiological effects of Huntington's disease may precede the development of overt clinical symptoms and detectable cerebral atrophy.

Conditional Probabilities in the Excursion Set Theory. Generic Barriers and non-Gaussian Initial Conditions

CERN Document Server

De Simone, Andrea; Riotto, Antonio

2011-01-01

The excursion set theory, where density perturbations evolve stochastically with the smoothing scale, provides a method for computing the dark matter halo mass function. The computation of the mass function is mapped into the so-called first-passage time problem in the presence of a moving barrier. The excursion set theory is also a powerful formalism to study other properties of dark matter halos such as halo bias, accretion rate, formation time, merging rate and the formation history of halos. This is achieved by computing conditional probabilities with non-trivial initial conditions, and the conditional two-barrier first-crossing rate. In this paper we use the recently-developed path integral formulation of the excursion set theory to calculate analytically these conditional probabilities in the presence of a generic moving barrier, including the one describing the ellipsoidal collapse, and for both Gaussian and non-Gaussian initial conditions. The non-Markovianity of the random walks induced by non-Gaussi...

The effect of job insecurity on employee health complaints: A within-person analysis of the explanatory role of threats to the manifest and latent benefits of work.

Science.gov (United States)

Vander Elst, Tinne; Näswall, Katharina; Bernhard-Oettel, Claudia; De Witte, Hans; Sverke, Magnus

2016-01-01

The current study contributes to the literature on job insecurity by highlighting threat to the benefits of work as an explanation of the effect of job insecurity on health complaints. Building on the latent deprivation model, we predicted that threats to both manifest (i.e., financial income) and latent benefits of work (i.e., collective purpose, social contacts, status, time structure, activity) mediate the relationships from job insecurity to subsequent mental and physical health complaints. In addition, in line with the conservation of resources theory, we proposed that financial resources buffer the indirect effect of job insecurity on health complaints through threat to the manifest benefit. Hypotheses were tested using a multilevel design, in which 3 measurements (time lag of 6 months between subsequent measurements) were clustered within 1,994 employees (in Flanders, Belgium). This allowed for the investigation of within-person processes, while controlling for variance at the between-person level. The results demonstrate that job insecurity was related to subsequent threats to both manifest and latent benefits, and that these threats in turn were related to subsequent health complaints (with an exception for threat to the manifest benefit that did not predict mental health complaints). Three significant indirect effects were found: threat to the latent benefits mediated the relationships between job insecurity and both mental and physical health complaints, and threat to the manifest benefit mediated the relationship between job insecurity and physical health complaints. Unexpectedly, the latter indirect effect was exacerbated by financial resources. (c) 2016 APA, all rights reserved).

Unusual Cutaneous Manifestation of Tuberous Sclerosis

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K C Shah

1980-01-01

Full Text Available Cutaneous manifestations are found in 60 to 70% cases of tuberous sclerosis and consist of adenoma sebaceum, periungual fibromatas, cafe au lait spots, shagreen patches and white macules. Our patient showed unusual skin manifestations like spotty pigmentation on the chest, back and abdomen and hyperkeratosis palmaris et plantaris.

40 CFR 265.71 - Use of manifest system.

Science.gov (United States)

2010-07-01

... the manifest; (iv) Within 30 days of delivery, send a copy of the manifest to the generator; and (v... Pennsylvania Avenue, NW., Washington, DC 20460. (b) If a facility receives, from a rail or water (bulk shipment... on the manifest (excluding the EPA identification numbers, generator's certification, and signatures...

Kinetics of the Dynamical Information Shannon Entropy for Complex Systems

International Nuclear Information System (INIS)

Yulmetyev, R.M.; Yulmetyeva, D.G.

1999-01-01

Kinetic behaviour of dynamical information Shannon entropy is discussed for complex systems: physical systems with non-Markovian property and memory in correlation approximation, and biological and physiological systems with sequences of the Markovian and non-Markovian random noises. For the stochastic processes, a description of the information entropy in terms of normalized time correlation functions is given. The influence and important role of two mutually dependent channels of the entropy change, correlation (creation or generation of correlations) and anti-correlation (decay or annihilation of correlation) is discussed. The method developed here is also used in analysis of the density fluctuations in liquid cesium obtained from slow neutron scattering data, fractal kinetics of the long-range fluctuation in the short-time human memory and chaotic dynamics of R-R intervals of human ECG. (author)

A simple method to calculate first-passage time densities with arbitrary initial conditions

Science.gov (United States)

Nyberg, Markus; Ambjörnsson, Tobias; Lizana, Ludvig

2016-06-01

Numerous applications all the way from biology and physics to economics depend on the density of first crossings over a boundary. Motivated by the lack of general purpose analytical tools for computing first-passage time densities (FPTDs) for complex problems, we propose a new simple method based on the independent interval approximation (IIA). We generalise previous formulations of the IIA to include arbitrary initial conditions as well as to deal with discrete time and non-smooth continuous time processes. We derive a closed form expression for the FPTD in z and Laplace-transform space to a boundary in one dimension. Two classes of problems are analysed in detail: discrete time symmetric random walks (Markovian) and continuous time Gaussian stationary processes (Markovian and non-Markovian). Our results are in good agreement with Langevin dynamics simulations.

The radiographic manifestations of hypochondroplasia

International Nuclear Information System (INIS)

Heselson, N.G.; Cremin, B.J.; Beighton, P.

1979-01-01

Hypochrondroplasia is an inherited skeletal dysplasia that resembles achondroplasia in mild degree. Radiographic manifestations encountered in 12 affected individuals in South Africa include slight shortening of all segments of the tubular bones, moderate caudal diminution of the lumbar interpedicular distances, increased lumbar lordosis with cacral tilt and distal prolongation of the fibular. Hypochondroplasia can be distinguished from other osteochondrodystrophies such as achondroplasia, pseudo-achondroplasia and metaphyseal chondroplasia by the recognition of it clinical and radiographic manifestations. (author)

Pulmonary manifestations of Sjögren's syndrome

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Thomas Flament

2016-06-01

Full Text Available In 9–20% of cases, Sjögren's syndrome is associated with various respiratory symptoms. The most typical manifestations are chronic interstitial lung disease (ILD and tracheobronchial disease. The most common manifestation of ILD is nonspecific interstitial pneumonia in its fibrosing variant. Other types of ILD, such as organising pneumonia, usual interstitial pneumonia and lymphocytic interstitial pneumonitis, are rare. Their radiological presentation is less distinctive, and definitive diagnosis may require the use of transbronchial or surgical lung biopsy. Corticosteroid therapy is the mainstay of ILD treatment in Sjögren's syndrome, but the use of other immunosuppressive drugs needs to be determined. ILD is a significant cause of death in Sjögren's syndrome. Tracheobronchial disease is common in Sjögren's syndrome, characterised by diffuse lymphocytic infiltration of the airway. It is sometimes responsible for a crippling chronic cough. It can also present in the form of bronchial hyperresponsiveness, bronchiectasis, bronchiolitis or recurrent respiratory infections. The management of these manifestations may require treatment for dryness and/or inflammation of the airways. Airway disease has little effect on respiratory function and is rarely the cause of death in Sjögren's syndrome patients. Rare respiratory complications such as amyloidosis, lymphoma or pulmonary hypertension should not be disregarded in Sjögren's syndrome patients.

21 CFR 11.50 - Signature manifestations.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Signature manifestations. 11.50 Section 11.50 Food... RECORDS; ELECTRONIC SIGNATURES Electronic Records § 11.50 Signature manifestations. (a) Signed electronic...: (1) The printed name of the signer; (2) The date and time when the signature was executed; and (3...

CT manifestation of schistosoma haematobium cystitis

International Nuclear Information System (INIS)

Wang Yujun; Hu Lirong; Cheng Yougen; Mao Guoqun; Yang Guangzhao; Modya Camara; Mohamed Traore

2014-01-01

Objective: To analyze CT manifestation of Schistosoma haematobium cystitis. Methods: Retrospective analysis 32 patients, who were tested for Schistosoma haematobium cystitis using the urine filtration method. CT scan was performed for each patient with contrast enhancement. Results: The vast majority of urinary tract schistomiasis lesions were in the urinary bladder. Calcification of the bladder wall was observed in all patients and mild enhancement in non calcified zone was found after intravenous contrast. Except for 5 patients of bladder cancer, the rest were no abnormality in size of bladder when bladder was filling or emptying. Ureteral wall annular calcification could also be identified in 25 patients. Twenty two patients were companied with ureteric hydronephrosis. Seminal vesicle calcification was seen in 4 patients among 11 male patients, while both uterine and ovarian in female and prostate in men had non calcification. Serious illness can be combined with bladder cancer. In 5 patients of patients with bladder cancer, bladder showed irregular soft tissue mass which was enhanced moderately after post-contrast scan, with vesical calcification in mass medially. Conclusion: Bladder calcification is the most prominent CT feature of Schistosoma haematobium cystitis, which is useful in diagnosis the disease. (authors)

Myelofibrosis-associated complications: pathogenesis, clinical manifestations, and effects on outcomes

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Mughal TI

2014-01-01

Full Text Available Tariq I Mughal,1 Kris Vaddi,2 Nicholas J Sarlis,2 Srdan Verstovsek31Tufts University School of Medicine, Boston, MA, 2Incyte Corporation, Wilmington, DE, 3Department of Leukemia, University of Texas MD Anderson Cancer Center, Houston, TX, USAAbstract: Myelofibrosis (MF is a rare chronic BCR-ABL1 (breakpoint cluster region-Abelson murine leukemia viral oncogene homologue 1-negative myeloproliferative neoplasm characterized by progressive bone marrow fibrosis, inefficient hematopoiesis, and shortened survival. The clinical manifestations of MF include splenomegaly, consequent to extramedullary hematopoiesis, cytopenias, and an array of potentially debilitating abdominal and constitutional symptoms. Dysregulated Janus kinase (JAK-signal transducer and activator of transcription signaling underlies secondary disease-associated effects in MF, such as myeloproliferation, bone marrow fibrosis, constitutional symptoms, and cachexia. Common fatal complications of MF include transformation to acute leukemia, thrombohemorrhagic events, organ failure, and infections. Potential complications from hepatosplenomegaly include portal hypertension and variceal bleeding, whereas extramedullary hematopoiesis outside the spleen and liver – depending on the affected organ – may result in intracranial hypertension, spinal cord compression, pulmonary hypertension, pleural effusions, lymphadenopathy, skin lesions, and/or exacerbation of abdominal symptoms. Although allogeneic stem cell transplantation is the only potentially curative therapy, it is suitable for few patients. The JAK1/JAK2 inhibitor ruxolitinib is effective in improving splenomegaly, MF-related symptoms, and quality-of-life measures. Emerging evidence that ruxolitinib may be associated with a survival benefit in intermediate- or high-risk MF suggests the possibility of a disease-modifying effect. Consequently, ruxolitinib could provide a treatment backbone to which other (conventional and novel

Fractional noise destroys or induces a stochastic bifurcation

Energy Technology Data Exchange (ETDEWEB)

Yang, Qigui, E-mail: qgyang@scut.edu.cn [School of Sciences, South China University of Technology, Guangzhou 510640 (China); Zeng, Caibin, E-mail: zeng.cb@mail.scut.edu.cn [School of Sciences, South China University of Technology, Guangzhou 510640 (China); School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China); Wang, Cong, E-mail: wangcong@scut.edu.cn [School of Automation Science and Engineering, South China University of Technology, Guangzhou 510640 (China)

2013-12-15

Little seems to be known about the stochastic bifurcation phenomena of non-Markovian systems. Our intention in this paper is to understand such complex dynamics by a simple system, namely, the Black-Scholes model driven by a mixed fractional Brownian motion. The most interesting finding is that the multiplicative fractional noise not only destroys but also induces a stochastic bifurcation under some suitable conditions. So it opens a possible way to explore the theory of stochastic bifurcation in the non-Markovian framework.

Manifestly T-dual formulation of AdS space

International Nuclear Information System (INIS)

Hatsuda, Machiko; Kamimura, Kiyoshi; Siegel, Warren

2017-01-01

We present a manifestly T-dual formulation of curved spaces such as an AdS space. For group manifolds related by the orthogonal vielbein fields the three form H=dB in the doubled space is universal at least locally. We construct an affine nondegenerate doubled bosonic AdS algebra to define the AdS space with the Ramond-Ramond flux. The non-zero commutator of the left and right momenta leads to that the left momentum is in an AdS space while the right momentum is in a dS space. Dimensional reduction constraints and the physical AdS algebra are shown to preserve all the doubled coordinates.

Manifestly T-dual formulation of AdS space

Energy Technology Data Exchange (ETDEWEB)

Hatsuda, Machiko [Physics Division, Faculty of Medicine, Juntendo University,Chiba 270-1695 (Japan); KEK Theory Center, High Energy Accelerator Research Organization,Tsukuba, Ibaraki 305-0801 (Japan); Kamimura, Kiyoshi [Physics Division, Faculty of Medicine, Juntendo University,Chiba 270-1695 (Japan); Siegel, Warren [C.N. Yang Institute for Theoretical Physics, Stony Brook University,Stony Brook, NY 11794-3840 (United States)

2017-05-12

We present a manifestly T-dual formulation of curved spaces such as an AdS space. For group manifolds related by the orthogonal vielbein fields the three form H=dB in the doubled space is universal at least locally. We construct an affine nondegenerate doubled bosonic AdS algebra to define the AdS space with the Ramond-Ramond flux. The non-zero commutator of the left and right momenta leads to that the left momentum is in an AdS space while the right momentum is in a dS space. Dimensional reduction constraints and the physical AdS algebra are shown to preserve all the doubled coordinates.

Manifestation of Incompleteness in Obsessive-Compulsive Disorder (OCD) as Reduced Functionality and Extended Activity beyond Task Completion

Science.gov (United States)

Zor, Rama; Szechtman, Henry; Hermesh, Haggai; Fineberg, Naomi A.; Eilam, David

2011-01-01

Background This study focused on hypotheses regarding the source of incompleteness in obsessive-compulsive disorder (OCD). For this, we had to document the behavioral manifestation of incompleteness in compulsive rituals, predicting that an exaggerated focus on acts that are appropriate for the task will support the hypothesis on heightened responsibility/perfectionism. In contrast, activity past the expected terminal act for the motor task would support the “stop signal deficiency” hypothesis. Methodology and Principal Findings We employed video-telemetry to analyze 39 motor OCD rituals and compared each with a similar task performed by a non-OCD individual, in order to objectively and explicitly determine the functional end of the activity. We found that 75% of OCD rituals comprised a “tail,” which is a section that follows the functional end of the task that the patients ascribed to their activity. The other 25% tailless rituals comprised a relatively high number and higher rate of repetition of non-functional acts. Thus, in rituals with tail, incompleteness was manifested by the mere presence of the tail whereas in tailless rituals, incompleteness was manifested by the reduced functionality of the task due to an inflated execution and repetition of non-functional acts. Conclusions The prevalence of activity after the functional end (“tail”) and the elevated non-functionality in OCD motor rituals support the “lack of stop signal” theories as the underlying mechanism in OCD. Furthermore, the presence and content of the tail might have a therapeutic potential in cognitive-behavior therapy. PMID:21966460

Constitutional FLCN mutations in patients with suspected Birt-Hogg-Dubé syndrome ascertained for non-cutaneous manifestations.

Science.gov (United States)

Maffé, A; Toschi, B; Circo, G; Giachino, D; Giglio, S; Rizzo, A; Carloni, A; Poletti, V; Tomassetti, S; Ginardi, C; Ungari, S; Genuardi, M

2011-04-01

Birt-Hogg-Dubé syndrome (BHDS) is characterized by a clinical triad including cutaneous hamartomas originating from hair follicles, lung cysts/pneumothorax, and kidney tumors. Inactivating mutations of the tumor suppressor gene FLCN are identified in most families with BHDS. Usually, patients are referred for genetic examination by dermatologists because of the presence of typical multiple skin tumors with or without additional symptoms. However, because of phenotypic variability and incomplete penetrance, the clinical presentation of BHDS is not yet fully defined. Criteria for genetic testing and diagnosis that take into account variable manifestations have recently been proposed by the European BHD Consortium. We sequenced the FLCN gene coding region in a series of 19 patients selected for kidney and/or lung manifestations. Overall, FLCN mutations were found in 9 of 19 (47%) families and were detected only in probands who had either >2 components of the clinical triad or a single component (renal or pulmonary) along with a family history of another main BHDS manifestation. Typical cutaneous lesions were present only in 8 of 21 FLCN mutation carriers aged >20 years identified in the mutation-positive families. In addition, we provide clinical and molecular evidence that parotid oncocytoma, so far reported in six BHDS cases, is associated with this condition, based on the observation of a patient with bilateral parotid involvement and marked reduction of the wild-type FLCN allele signal in tumor DNA. Overall, the results obtained in this study contribute to the definition of the phenotypic characteristics that should be considered for BHDS diagnosis and FLCN mutation testing. © 2010 John Wiley & Sons A/S.

Fractal-Markovian scaling of turbulent bursting process in open channel flow

International Nuclear Information System (INIS)

Keshavarzi, Ali Reza; Ziaei, Ali Naghi; Homayoun, Emdad; Shirvani, Amin

2005-01-01

The turbulent coherent structure of flow in open channel is a chaotic and stochastic process in nature. The coherence structure of the flow or bursting process consists of a series of eddies with a variety of different length scales and it is very important for the entrainment of sediment particles from the bed. In this study, a fractal-Markovian process is applied to the measured turbulent data in open channel. The turbulent data was measured in an experimental flume using three-dimensional acoustic Doppler velocity meter (ADV). A fractal interpolation function (FIF) algorithm was used to simulate more than 500,000 time series data of measured instantaneous velocity fluctuations and Reynolds shear stress. The fractal interpolation functions (FIF) enables to simulate and construct time series of u', v', and u'v' for any particular movement and state in the Markov process. The fractal dimension of the bursting events is calculated for 16 particular movements with the transition probability of the events based on 1st order Markov process. It was found that the average fractal dimensions of the streamwise flow velocity (u') are; 1.73, 1.74, 1.71 and 1.74 with the transition probability of 60.82%, 63.77%, 59.23% and 62.09% for the 1-1, 2-2, 3-3 and 4-4 movements, respectively. It was also found that the fractal dimensions of Reynold stress u'v' for quadrants 1, 2, 3 and 4 are 1.623, 1.623, 1.625 and 1.618, respectively

Soft tissue manifestations of early rheumatic disease. Imaging with MRI

International Nuclear Information System (INIS)

Treitl, M.; Panteleon, A.; Koerner, M.; Becker-Gaab, C.; Reiser, M.; Wirth, S.

2006-01-01

The aim of this study was to evaluate typical magnetic resonance imaging (MRI) findings in early rheumatic diseases manifesting at the soft tissues of the hand using a retrospective analysis. A total of 186 MRI examinations of patients with clinical suspicion of a rheumatic disease were evaluated in a consensus reading by two experienced radiologists. All imaging patterns were assessed with respect to their type and localization. Under blinded and non-blinded conditions diagnoses were correlated with final clinical diagnosis. The most frequent diagnoses were rheumatoid arthritis (RA, 45.7%) and psoriatic arthritis (PsA, 15.6%). The mean correlation between clinical and MRI diagnosis (r) was 0.75 in blinded and 0.853 in non-blinded reading (p [de

Stochastic Wilson–Cowan models of neuronal network dynamics with memory and delay

International Nuclear Information System (INIS)

Goychuk, Igor; Goychuk, Andriy

2015-01-01

We consider a simple Markovian class of the stochastic Wilson–Cowan type models of neuronal network dynamics, which incorporates stochastic delay caused by the existence of a refractory period of neurons. From the point of view of the dynamics of the individual elements, we are dealing with a network of non-Markovian stochastic two-state oscillators with memory, which are coupled globally in a mean-field fashion. This interrelation of a higher-dimensional Markovian and lower-dimensional non-Markovian dynamics is discussed in its relevance to the general problem of the network dynamics of complex elements possessing memory. The simplest model of this class is provided by a three-state Markovian neuron with one refractory state, which causes firing delay with an exponentially decaying memory within the two-state reduced model. This basic model is used to study critical avalanche dynamics (the noise sustained criticality) in a balanced feedforward network consisting of the excitatory and inhibitory neurons. Such avalanches emerge due to the network size dependent noise (mesoscopic noise). Numerical simulations reveal an intermediate power law in the distribution of avalanche sizes with the critical exponent around −1.16. We show that this power law is robust upon a variation of the refractory time over several orders of magnitude. However, the avalanche time distribution is biexponential. It does not reflect any genuine power law dependence. (paper)

Memory effects in single-molecule spectroscopy

International Nuclear Information System (INIS)

Schmitt, Daniel T.; Schulz, Michael; Reineker, Peter

2007-01-01

From the time series of LH2 optical single-molecule fluorescence excitation spectra of Rhodospirillum molischianum the memory function of the Mori-Zwanzig equation for the optical intensity is derived numerically. We show that the time dependence of the excited states is determined by at least three different non-Markovian stochastic processes with decay constants for the Mori-Zwanzig kernel on the order of 1-5min -1 . We suggest that this decay stems from the conformational motion of the protein scaffold of LH2

Quantum manifestations of Nekhoroshev stability

Energy Technology Data Exchange (ETDEWEB)

Fontanari, Daniele, E-mail: fontanari@purple.univ-littoral.fr [Département de physique, Université du Littoral – Côte d' Opale, 59140 Dunkerque (France); Fassò, Francesco, E-mail: fasso@math.unipd.it [Università di Padova, Dipartimento di Matematica, Via Trieste 63, Padova 35121 (Italy); Sadovskií, Dmitrií A., E-mail: sadovski@univ-littoral.fr [Département de physique, Université du Littoral – Côte d' Opale, 59140 Dunkerque (France)

2016-09-16

We uncover quantum manifestations of classical Nekhoroshev theory of resonant dynamics using a simple quantum system of two coupled angular momenta with conserved equal magnitudes which corresponds to a perturbed classical integrable anisochronous Hamiltonian system. - Highlights: • Basic quantum manifestations of classical Nekhoroshev theory are studied. • A simple anisochronous convex system with two degrees of freedom is proposed. • Zones are uncovered in the joint expectation value spectrum of quantized actions. • The width of the zones is given by the Nekhoroshev resonant normal forms.

Lactoferrin dampens high-fructose corn syrup-induced hepatic manifestations of the metabolic syndrome in a murine model.

Directory of Open Access Journals (Sweden)

Yi-Chieh Li

Full Text Available Hepatic manifestations of the metabolic syndrome are related obesity, type 2 diabetes/insulin resistance and non-alcoholic fatty liver disease. Here we investigated how the anti-inflammatory properties of lactoferrin can protect against the onset of hepatic manifestations of the metabolic syndrome by using a murine model administered with high-fructose corn syrup. Our results show that a high-fructose diet stimulates intestinal bacterial overgrowth and increases intestinal permeability, leading to the introduction of endotoxin into blood circulation and liver. Immunohistochemical staining of Toll-like receptor-4 and thymic stromal lymphopoietin indicated that lactoferrin can modulate lipopolysaccharide-mediated inflammatory cascade. The important regulatory roles are played by adipokines including interleukin-1β, interleukin-6, tumor necrosis factor-α, monocyte chemotactic protein-1, and adiponectin, ultimately reducing hepatitis and decreasing serum alanine aminotransferase release. These beneficial effects of lactoferrin related to the downregulation of the lipopolysaccharide-induced inflammatory cascade in the liver. Furthermore, lactoferrin reduced serum and hepatic triglycerides to prevent lipid accumulation in the liver, and reduced lipid peroxidation, resulting in 4-hydroxynonenal accumulation. Lactoferrin reduced oral glucose tolerance test and homeostasis model assessment-insulin resistance. Lactoferrin administration thus significantly lowered liver weight, resulting from a decrease in the triglyceride and cholesterol synthesis that activates hepatic steatosis. Taken together, these results suggest that lactoferrin protected against high-fructose corn syrup induced hepatic manifestations of the metabolic syndrome.

Lactoferrin dampens high-fructose corn syrup-induced hepatic manifestations of the metabolic syndrome in a murine model.

Science.gov (United States)

Li, Yi-Chieh; Hsieh, Chang-Chi

2014-01-01

Hepatic manifestations of the metabolic syndrome are related obesity, type 2 diabetes/insulin resistance and non-alcoholic fatty liver disease. Here we investigated how the anti-inflammatory properties of lactoferrin can protect against the onset of hepatic manifestations of the metabolic syndrome by using a murine model administered with high-fructose corn syrup. Our results show that a high-fructose diet stimulates intestinal bacterial overgrowth and increases intestinal permeability, leading to the introduction of endotoxin into blood circulation and liver. Immunohistochemical staining of Toll-like receptor-4 and thymic stromal lymphopoietin indicated that lactoferrin can modulate lipopolysaccharide-mediated inflammatory cascade. The important regulatory roles are played by adipokines including interleukin-1β, interleukin-6, tumor necrosis factor-α, monocyte chemotactic protein-1, and adiponectin, ultimately reducing hepatitis and decreasing serum alanine aminotransferase release. These beneficial effects of lactoferrin related to the downregulation of the lipopolysaccharide-induced inflammatory cascade in the liver. Furthermore, lactoferrin reduced serum and hepatic triglycerides to prevent lipid accumulation in the liver, and reduced lipid peroxidation, resulting in 4-hydroxynonenal accumulation. Lactoferrin reduced oral glucose tolerance test and homeostasis model assessment-insulin resistance. Lactoferrin administration thus significantly lowered liver weight, resulting from a decrease in the triglyceride and cholesterol synthesis that activates hepatic steatosis. Taken together, these results suggest that lactoferrin protected against high-fructose corn syrup induced hepatic manifestations of the metabolic syndrome.

Articular manifestations in patients with Lyme disease.

Science.gov (United States)

Vázquez-López, María Esther; Díez-Morrondo, Carolina; Sánchez-Andrade, Amalia; Pego-Reigosa, Robustiano; Díaz, Pablo; Castro-Gago, Manuel

To determine the percentage of Lyme patients with articular manifestations in NW Spain and to know their evolution and response to treatment. A retrospective study (2006-2013) was performed using medical histories of confirmed cases of Lyme disease showing articular manifestations. Clinical and laboratory characteristics, together with the treatment and evolution of the patients, were analysed. Seventeen out of 108 LD confirmed patients (15.7%) showed articular manifestations. Regarding those 17 patients, 64.7%, 29.4% and 5.9% presented arthritis, arthralgia and bursitis, respectively. The knee was the most affected joint. Articular manifestations were often associated to neurological, dermatological and cardiac pathologies. Otherwise, most patients were in Stage III. The 11.8% of the cases progressed to a recurrent chronic arthritis despite the administration of an appropriate treatment. Lyme disease patients showing articular manifestations should be included in the diagnosis of articular affections in areas of high risk of hard tick bite, in order to establish a suitable and early treatment and to avoid sequels. Copyright © 2015 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

Multi-scale inference of interaction rules in animal groups using Bayesian model selection.

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Richard P Mann

Full Text Available Inference of interaction rules of animals moving in groups usually relies on an analysis of large scale system behaviour. Models are tuned through repeated simulation until they match the observed behaviour. More recent work has used the fine scale motions of animals to validate and fit the rules of interaction of animals in groups. Here, we use a Bayesian methodology to compare a variety of models to the collective motion of glass prawns (Paratya australiensis. We show that these exhibit a stereotypical 'phase transition', whereby an increase in density leads to the onset of collective motion in one direction. We fit models to this data, which range from: a mean-field model where all prawns interact globally; to a spatial Markovian model where prawns are self-propelled particles influenced only by the current positions and directions of their neighbours; up to non-Markovian models where prawns have 'memory' of previous interactions, integrating their experiences over time when deciding to change behaviour. We show that the mean-field model fits the large scale behaviour of the system, but does not capture the observed locality of interactions. Traditional self-propelled particle models fail to capture the fine scale dynamics of the system. The most sophisticated model, the non-Markovian model, provides a good match to the data at both the fine scale and in terms of reproducing global dynamics, while maintaining a biologically plausible perceptual range. We conclude that prawns' movements are influenced by not just the current direction of nearby conspecifics, but also those encountered in the recent past. Given the simplicity of prawns as a study system our research suggests that self-propelled particle models of collective motion should, if they are to be realistic at multiple biological scales, include memory of previous interactions and other non-Markovian effects.

[Clinical manifestation and cytogenetic analysis of 607 patients with Turner syndrome].

Science.gov (United States)

Zheng, Jiemei; Liu, Zhiying; Xia, Pei; Lai, Yi; Wei, Yangjun; Liu, Yanyan; Chen, Jiurong; Qin, Li; Xie, Liangyu; Wang, He

2017-02-10

To explore the correlation between cytogenetic findings and clinical manifestations of Turner syndrome. 607 cases of cytogenetically diagnosed Turner syndrome, including those with a major manifestation of Turner syndrome, were analyzed with conventional G-banding. Correlation between the karyotypes and clinical features were analyzed. Among the 607 cases, there were 154 cases with monosomy X (25.37%). Mosaicism monosomy X was found in 240 patients (39.54%), which included 194 (80.83%) with a low proportion of 45,X (3 ≤ the number of 45, X ≤5, while the normal cells ≥ 30). Structural X chromosome abnormalities were found in 173 patients (28.50%). A supernumerary marker chromosome was found in 40 cases (6.59%). Most patients with typical manifestations of Turner syndrome were under 11 years of age and whose karyotypes were mainly 45,X. The karyotype of patients between 11 and 18 years old was mainly 45,X, 46,X,i(X)(q10) and mos45,X/46,X,i(X)(q10), which all had primary amenorrhea in addition to the typical clinical manifestations. The karyotype of patients over 18 years of age were mainly mosaicism with a low proportion of 45,X, whom all had primary infertility. 53 patients had a history of pregnancy, which included 48 with non-structural abnormalities of X chromosome and 5 with abnormal structure of X chromosome. Generally, the higher proportion of cells with an abnormal karyotype, the more severe were the clinical symptoms and the earlier clinical recognition. Karyotyping analysis can provide guidance for the early diagnosis of Turner syndrome, especially those with a low proportion of 45,X.

Osteomalacia as inaugural manifestation of Sjögren syndrome.

Science.gov (United States)

Cherif, Eya; Ben Hassine, Lamia; Kaoueche, Zouleikha; Khalfallah, Narjess

2013-10-09

Osteomalacia is a relatively common condition, which is frequently underdiagnosed due to lack of clinical suspicion and non-specific symptoms. Osteomalacia can complicate tubulo-interstital nephritis. However, it occurs exceptionally as the first manifestation of Sjögren syndrome with renal involvement. It is a consequence of chronic metabolic acidosis and is associated with distal renal tubular acidosis. We report a 31-year-old woman hospitalised for a 1 year history of muscle weakness and joint and chest wall pains. Skeletal imagery showed Looser's zones in the left femoral neck. Investigations concluded to the diagnosis of primary Sjogren's syndrome.

Delayed manifestation and transmission bias of de novo chromosome mutations. Their relevance for radiation health effect

International Nuclear Information System (INIS)

Sasaki, Masao S.

2006-01-01

The origin and transmission of de novo chromosome mutations were reviewed on the basis of our chromosome studies in retinoblastoma patients and male infertility. In a series of 264 sporadic retinoblastoma families, gross chromosome rearrangements involving the RB1 locus were identified in 23 cases (8.7%), of which 16 were non-mosaic and 7 were mosaic mutations. The newly formed chromosome mutations, whether they were non-mosaic or mosaic, had a strong bias towards paternally derived chromosome, indicating that they shared a common mechanism where a pre-mutational event or instability is carried over to zygote by sperm and manifested as gross chromosome mutation at the early stages of development. The de novo chromosome mutations are preferentially transmitted through female carriers. This transmission bias is consistent with the finding of higher frequencies of translocation carriers in infertile men (7.69% versus 0.27% in general populations) in whom meiotic progression is severely suppressed, possibly through activation of meiotic checkpoints. Such a meiotic surveillance mechanism may minimize the spreading of newly-arisen chromosome mutations in populations. A quantitative model of meiotic surveillance mechanism is proposed and successfully applied to the published data on ''humped'' dose-response curves for radiation-induced spermatogonial reciprocal translocations in several mammalian species. (author)

Critical Reflections on the Hydrophobic Effect, its Origins and Manifestation: Water Structure, Chemical Reactivity, Micelles and Gels.

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Sosale Chandrasekhar

2017-09-01

Full Text Available The origins of the Hydrophobic Effect (HE, its biological significance and its experimental basis are critically addressed in this brief review. It is argued that the mechanistic work reported on the HE in recent decades needs to be reassessed, as its conclusions are apparently debatable. Essentially, it is highly inaccurate to view the HE as a repulsive interaction, which is rather an attractive one. It appears inevitable that the HE is indeed a manifestation of the perturbation of the structure of water upon the introduction of hydrocarbon molecules into its interior. There appears to be no other satisfactory explanation for the formation of micellar aggregates and the existence of the critical micelle concentration. Also, the practical significance of the HE on the reactivity of organic compounds (e.g. cycloadditions is severely limited by their minuscule solubility levels, itself a manifestation of the HE! Other related phenomena apparently include the formation of gels and the occurrence of certain esterification reactions in water, which are briefly reviewed from a conceptual viewpoint.

Cardio-pulmonary manifestations of rheumatoid arthritis among ...

African Journals Online (AJOL)

Background: Rheumatoid arthritis is a chronic systemic inflammatory disease, characterized by polyarthritis and extraarticular manifestations. The cardiopulmonary manifestations of rheumatoid arthritis were studied retrospectively in a cohort of rheumatoid arthritis patients. Methods: This was a retrospective study of all ...

Impacts of complex behavioral responses on asymmetric interacting spreading dynamics in multiplex networks.

Science.gov (United States)

Liu, Quan-Hui; Wang, Wei; Tang, Ming; Zhang, Hai-Feng

2016-05-09

Information diffusion and disease spreading in communication-contact layered network are typically asymmetrically coupled with each other, in which disease spreading can be significantly affected by the way an individual being aware of disease responds to the disease. Many recent studies have demonstrated that human behavioral adoption is a complex and non-Markovian process, where the probability of behavior adoption is dependent on the cumulative times of information received and the social reinforcement effect of the cumulative information. In this paper, the impacts of such a non-Markovian vaccination adoption behavior on the epidemic dynamics and the control effects are explored. It is found that this complex adoption behavior in the communication layer can significantly enhance the epidemic threshold and reduce the final infection rate. By defining the social cost as the total cost of vaccination and treatment, it can be seen that there exists an optimal social reinforcement effect and optimal information transmission rate allowing the minimal social cost. Moreover, a mean-field theory is developed to verify the correctness of simulation results.

Structural manifestations of aging in Se-rich glasses

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Dash, S.; Ravindren, S.; Chen, P.; Boolchand, P.

2015-03-01

We examine weakly cross-linked GexSe100-x (0%modulated DSC and Raman scattering experiments. Homogeneity of melts was carefully verified using FT-Raman line profiling. Upon aging at RT for 4 months, we find the width of the glass transition W(x) steadily decreasing from 10C at 7% Ge to 2C for pure Se. The 5-fold reduction of W(x) with a decrease of Ge content is accompanied by a 2-fold increase in the non-reversing enthalpy. Rejuvenation of the aged glasses changes W(x) from 15C at 7% Ge to 7C for pure Se. Tg is found to decrease upon rejuvenation with the difference (Tg(aged)-Tg(rejuv)) showing a maximum near 3% Ge and vanishing for pure Se and 6% of Ge, which are topological thresholds. These results in Se-rich glasses are consistent with aging induced decoupling of Se8 crowns and growth of extended range structural correlations between polymeric Sen chains due to lone pair interactions. At higher x, near 8-10% of Ge, eutectic effects are manifested. Work supported by NSF Grant DMR 08-53957.

Manifest Dream Content as a Predictor of Suicidality.

Science.gov (United States)

Glucksman, Myron L; Kramer, Milton

2017-01-01

A number of behavioral, social, biological, and cultural factors are associated with suicide. However, the ability to predict an imminent suicide attempt remains problematic. Prior studies indicate that the manifest dream content of depressed, non-suicidal patients differs from that of depressed, suicidal patients. The dream imagery of depressed, suicidal patients contains themes of death, dying, violence, and departure. The dream imagery of depressed, non-suicidal patients contains themes of rejection, helplessness, hopelessness, humiliation, failure, and loss. In the present study, the dream reports of 52 depressed patients were collected and rated for various themes. Patients were divided into three groups: Depressed and non-suicidal; Depressed, with suicidal ideation; Depressed, with suicidal ideation and/or attempt(s). Themes of death and/or dying, and to a lesser extent, themes of violence, injury, and/or murder occurred with greater frequency in the dream reports of depressed patients with suicidal ideation and/or attempts, than in the dream reports of depressed patients without suicidal ideation or behavior. These observations correspond with the prevailing psychodynamic explanation of suicide; namely, that it is a murderous attack on the self that is identified with hated internalized objects.

Bose-Hubbard lattice as a controllable environment for open quantum systems

Science.gov (United States)

Cosco, Francesco; Borrelli, Massimo; Mendoza-Arenas, Juan José; Plastina, Francesco; Jaksch, Dieter; Maniscalco, Sabrina

2018-04-01

We investigate the open dynamics of an atomic impurity embedded in a one-dimensional Bose-Hubbard lattice. We derive the reduced evolution equation for the impurity and show that the Bose-Hubbard lattice behaves as a tunable engineered environment allowing one to simulate both Markovian and non-Markovian dynamics in a controlled and experimentally realizable way. We demonstrate that the presence or absence of memory effects is a signature of the nature of the excitations induced by the impurity, being delocalized or localized in the two limiting cases of a superfluid and Mott insulator, respectively. Furthermore, our findings show how the excitations supported in the two phases can be characterized as information carriers.

OCULAR MANIFESTATIONS OF HEAD INJURIES

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Kanukollu Venkata Madusudana Rao

2016-12-01

Full Text Available BACKGROUND This prospective study aimed to evaluate the incidence of ocular manifestations in head injury and their correlation with the intracranial lesions. MATERIALS AND METHODS A total of 108 consecutive cases of closed head injury admitted in the neurosurgical ward of a tertiary teaching hospital underwent a thorough ophthalmic assessment. Clinical examination, radiological imaging and Glasgow Coma Scale (GCS were applied to grade the severity of injury. RESULTS Total number of 108 patients of head injury were examined of which 38 patients had ocular manifestations (35.18%. Of these, 85.18% were males, 84% of injuries were due to road traffic accidents and 16% were due to fall from a height. The ocular manifestations were as follows- Orbital complications were seen in 6 patients (15.8%. Anterior segment manifestations included black eyes seen in 10 patients (26.3%, subconjunctival haemorrhage in 10.5% of patients (4 patients, corneal involvement in 21% of patients (8 patients and pupillary involvement in 50% of patients (19 patients. Posterior segment manifestations were seen in 26.3% of patients (10 patients and were as follows- Purtscher’s retinopathy in 2 patients and optic atrophy in 5 patients. Cranial nerve palsies were seen in 15 patients (39.47% and supranuclear movement disorders were seen in 3 patients (8%. CONCLUSION Even though, neurosurgeons perform comprehensive clinical examination including eye examination, the main purpose is limited to aid topical diagnosis of neurological lesions. This study emphasises the importance of a detailed eye examination by an ophthalmologist to prevent irreversible visual loss in addition to aiding in the neurological diagnosis. Pupillary involvement, papilloedema and ocular motor paresis pointed to a more severe head injury. This observational prospective study helped us to correlate the severity of head injuries in association with ocular findings in patients admitted in neurosurgical ward

p.H1069Q mutation in ATP7B and biochemical parameters of copper metabolism and clinical manifestation of Wilson's disease.

Science.gov (United States)

Gromadzka, Graznya; Schmidt, Harmut H J; Genschel, Janine; Bochow, Bettina; Rodo, M; Tarnacka, Beatek; Litwin, Thomas; Chabik, Grzegorz; Członkowska, Anna

2006-02-01

We compared the effect of the p.H1069Q mutation and other non-p.H1069Q mutations in ATP7B on the phenotypic expression of Wilson's disease (WD), and assessed whether the clinical phenotype of WD in compound heterozygotes depends on the type of mutation coexisting with the p.H1069Q. One hundred forty-two patients with clinically, biochemically, and genetically diagnosed WD were studied. The mutational analysis of ATP7B was performed by direct sequencing. A total number of 26 mutations in ATP7B were identified. The p.His1069Gln was the most common mutation (allelic frequency: 72%). Seventy-three patients were homozygous for this mutation. Of compound heterozygotes, 37 had frameshift/nonsense mutation, and 20 had other missense mutation on one of their ATP7B alleles. Twelve patients had two non-p.H1069Q mutations. Patients homozygous for the p.H1069Q mutation had the less severe disturbances of copper metabolism and the latest presentation of first WD symptoms. The most severely disturbed copper metabolism and the earliest age at initial disease manifestation was noticed in non-p.H1069Q patients. In compound heterozygotes, the type of mutation coexisting with the p.H1069Q to a small extent influenced WD phenotype. The phenotype of WD varied considerably among patients with the same genotype. The p.H1069Q mutation is associated with late WD manifestation and with a mild disruption of copper metabolism. In compound heterozygotes, the phenotype of WD to a small extent depends on the type of mutation coexisting with the p.H1069Q. Besides genotype, additional modifying factors seem to determine WD manifestations. Copyright (c) 2005 Movement Disorder Society.

Quantum manifestations of chaos

International Nuclear Information System (INIS)

Borondo, F.; Benito, R.M.

1998-01-01

The correspondence between classical and quantum mechanics is considered both in the regular and chaotic regimes, and the main results regarding the quantum manifestations of chaos are reviewed. (Author) 16 refs

Inter-arm systolic blood pressure differences, relations with future vascular events and mortality in patients with and without manifest vascular disease.

Science.gov (United States)

Kranenburg, Guido; Spiering, Wilko; de Jong, Pim A; Kappelle, L Jaap; de Borst, Gert Jan; Cramer, Maarten J; Visseren, Frank L J; Aboyans, Victor; Westerink, Jan

2017-10-01

Inter-arm systolic blood pressure difference (SBPD) is an easily obtained patient characteristic which relates to vascular disease. We aimed to identify determinants of large inter-arm SBPD and to investigate the relation between inter-arm SBPD and vascular events in patients with and without manifest vascular disease. In a cohort of 7344 patients with manifest vascular disease or vascular risk factors alone enrolled in the Second Manifestations of ARTerial disease (SMART) study, single bilateral non-simultaneous blood pressure measurements were performed. Logistic and Cox regression was used to identify determinants of large inter-arm SBPD (≥15mmHg) and to investigate the relation between inter-arm SBPD and vascular events (composite of non-fatal myocardial infarction, stroke, and vascular mortality) and all-cause mortality. In all patients the median inter-arm SBPD was 7mmHg (IQR 3-11) and 1182 (16%) patients had inter-arm SBPD ≥15mmHg. Higher age, higher systolic blood pressure, diabetes mellitus, peripheral artery disease, carotid artery stenosis, higher carotid intima-media thickness, and lower ankle-brachial indices were related to large inter-arm SBPD (≥15mmHg). Each 5mmHg increase in inter-arm SBPD was related to a 12% higher risk of vascular events in patients without manifest vascular disease (HR 1.12; 95% CI 1.00-1.27), whereas no relation was apparent in patients with manifest vascular disease (HR 0.98; 95% CI 0.93-1.04, interaction p-value 0.036). Inter-arm SBPD was not related to all-cause mortality (HR 1.05; 95% CI 0.93-1.19). Inter-arm SBPD relates to a higher risk of vascular events in patients without manifest vascular disease, whereas this relation is not apparent in patients with manifest vascular disease. Copyright © 2017 Elsevier B.V. All rights reserved.

A Clinico- Epidemiological Study Of Filarial Related Orthopaedic Manifestations

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Patond K.R

1992-01-01

Full Text Available An epidemiological study was undertaken to study the incidence and distribution of orthopaedic manifestations of filariasis in an endemic area. A total of 207 cases were clinically examined and investigated. Patients were divided into three groups , viz., Group A: Orthopaedic manifestations with no history of filariasis . Group B: Orthopaedic manifestations with history of filariasis such as microfilaraemia or filarial fevers etc., Group C: Orthopaedic manifestations with chronic manifestations such as elephantiasis, hydrocele etc. To confirm filarial etiology, all the cases were examined for the presence of filarial antibody by indirect ELISA using wuchereda bancrofti microfilarial excretory- secretary antigen (wd Mf ESAg . A total of 61 of 102 patients of Group A, 14 of 21 patients of group B, and 73 of 84 patients of Group C were positive for filarial antibody. This study showed the prevalence of filarial antibody in about 71.4% of various orthopaedic manifestations.

Oral manifestations among people living with HIV/AIDS in Tanzania

DEFF Research Database (Denmark)

Fabian, F M; Kahabuka, F K; Petersen, P E

2009-01-01

BACKGROUND: This study aimed to determine the prevalence of various oral and peri-oral manifestations in people living with HIV/AIDS in Tanzania. METHODS: A cross sectional study. A total of 187 persons with HIV infection were recruited from non-governmental organisations serving people living...... associated with low body mass index (BMI). CONCLUSION: This community survey carried out in an African sub-Saharan country showed that oral lesions are frequent among people living with HIV/AIDS. As emphasised by the World Health Organization Global Oral Health Programme, national HIV/AIDS programmes should...

Stochastic Lorentz forces on a point charge moving near the conducting plate

International Nuclear Information System (INIS)

Hsiang, J.-T.; Wu, T.-H.; Lee, D.-S.

2008-01-01

The influence of quantized electromagnetic fields on a nonrelativistic charged particle moving near a conducting plate is studied. We give a field-theoretic derivation of the nonlinear, non-Markovian Langevin equation of the particle by the method of Feynman-Vernon influence functional. This stochastic approach incorporates not only the stochastic noise manifested from electromagnetic vacuum fluctuations, but also dissipation backreaction on a charge in the form of the retarded Lorentz forces. Since the imposition of the boundary is expected to anisotropically modify the effects of the fields on the evolution of the particle, we consider the motion of a charge undergoing small-amplitude oscillations in the direction either parallel or normal to the plane boundary. Under the dipole approximation for nonrelativistic motion, velocity fluctuations of the charge are found to grow linearly with time in the early stage of the evolution at the rather different rate, revealing strong anisotropic behavior. They are then asymptotically saturated as a result of the fluctuation-dissipation relation, and the same saturated value is found for the motion in both directions. The observational consequences are discussed

Genetic alterations in syndromes with oral manifestations

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Krishnamurthy Anuthama

2013-01-01

Full Text Available Ever since Gregor Johan Mendel proposed the law of inheritance, genetics has transcended the field of health and has entered all walks of life in its application. Thus, the gene is the pivoting factor for all happenings revolving around it. Knowledge of gene mapping in various diseases would be a valuable tool in prenatally diagnosing the condition and averting the future disability and stigma for the posterity. This article includes an array of genetically determined conditions in patients seen at our college out-patient department with complete manifestation, partial manifestation and array of manifestations not fitting into a particular syndrome.

Extraintestinal manifestations of inflammatory bowel disease: epidemiology, diagnosis, and management

DEFF Research Database (Denmark)

Larsen, Signe; Bendtzen, Klaus; Nielsen, Ole Haagen

2010-01-01

', 'bronchiectasis', 'bronchitis', 'cutaneous manifestations', 'erythema nodosum', 'extraintestinal manifestations', 'hyperhomocysteinemia', 'infliximab', 'iridocyclitis', 'lung disease', 'ocular manifestations', 'osteomalacia', 'pancreatitis', 'primary sclerosing cholangitis', 'renal stones', 'sulfasalazine...

Are the cutaneous manifestations in patients with primary antiphospholipid syndrome a marker for predicting lung manifestations?

Science.gov (United States)

Kontic, Milica; Stojanovich, Ljudmila; Mijailović-Ivković, Milena; Velinović, Mladen; Srnka, Jasminka; Zdravkovic, Marija

2018-01-01

The aim of this study was to investigate association between pulmonary and skin manifestations in a large group of patients with primary antiphospholipid syndrome (PAPS) as well as their connection with antiphospholipid antibodies. Our prospective study comprises of 390 patients with primary APS. Antiphospholipid antibody (aPL) analysis included detection of aCL (IgG/IgM), ß2GPI (IgG/IgM) and LA. Distinct pulmonary and skin associations were determined, as well as their associations with aPL. In PAPS patients the presence of LA was more common in PTE (p=0.005) and in pulmonary microthrombosis (p=0.003). We revealed statistical significance considering the presence of aCL IgM and pulmonary microthrombosis (p=0.05). Skin ulcerations correlated with positive titres aCL IgM and ß2 GPI IgM (p=0.03 and 0.04, respectively), while pseudovasculitis correlated with positive titres ß2 GPI IgM (p=0.02). PAPS patients were more more likely to develop pulmonary thromboembolisam if they had livedo reticularis (p=0.005), skin ulcerations (p=0.007), pseudovasculitic lesions (p=0.01), superficial cutaneous necrosis (p=0.005), and digital gangrene (p=0.02). Patients were also more prone to pulmonary microthrombosis if they already had livedo reticularis (p=0.03), skin ulcerations (p=0.007), pseudovasculitic lesions (p=0.05), superficial cutaneous necrosis (p=0.006), and digital gangrene (p=0.02). There is strong link between some pulmonary and skin manifestations in PAPS patients, suggesting complexity and evolutionary nature of APS. The presence of skin manifestations may be a high risk factor for several types of serious pulmonary manifestations in PAPS. Certain aPL types are associated with distinct pulmonary and skin manifestation, suggesting their predictive role.

CT manifestations of pulmonary Langerhans cell histiocytosis

International Nuclear Information System (INIS)

Qiang Jun; Yu Wei; Gao Wanqin; Song Haiqiao; Ma Yingjian

2010-01-01

Objective: To analyzes the CT manifestations of pulmonary Langerhans cell histiocytosis (PLCH). Methods: CT features of 11 patients with PLCH proved pathologically were analyzed retrospectively. Results: The main findings in 11 PLCHs were cysts and nodules. Two cases only had cysts, and 1 only had nodules, which most had cavitations. The other 8 cases showed cysts and nodules with 4 cases mainly manifested with cysts and nine mainly manifested with nodules. Two cases had pulmonary interstitial changes. One case only had cysts in the left upper lung field and 10 cases had lesions not only in the upper and middle but in the lower lung field, which 2 cases had more lesions in the lower and costo-phrenic angle field and 8 cases had less lesions in the costo-phrenic angle field. Three of these 8 cases had more lesions in the superior lobe and apical segment of lower lobe. Conclusion: CT manifestations of PLCH are helpful for the early diagnosis. (authors)

Zeolitization at uranium ore manifestation

International Nuclear Information System (INIS)

Petrosyan, R.V.; Buntikova, A.F.

1981-01-01

The process of zeolitization at uranium ore manifestation is studied. A specific type of low-temperature wall endogenous alteration of rocks due to the effect of primary acid solution with low content of carbonic acid is established. Leaching of calcium from enclosing rocks and its deposition in ore-accompanying calcium zeolites is a characteristic feature of wall-metasomatosis. Formation of desmin- calcite-laumontite and quartz-fluoroapatite of vein associations, including ore minerals (uranophane and metaotenite), is genetically connected with calcium metasomatosis. On the basis of the connection of ore minerals with endogeneous process of zeolitization a conclusion can be made on endogenous origin of uranophane and metaotenite [ru

Energy and angular-momentum non-conservation in four-dimensional gauge theories

International Nuclear Information System (INIS)

Manohar, A.

1985-01-01

We study energy and angular-momentum non-conservation on four-dimensional chiral gauge theories using Landau levels. These effects are physical manifestations of the usual gauge anomaly, and enable us to understand in a semi-classical approximation why anomaly cancellation is required for a consistent field theory. (orig.)

Gaussian Error Correction of Quantum States in a Correlated Noisy Channel

DEFF Research Database (Denmark)

Lassen, Mikael Østergaard; Berni, Adriano; Madsen, Lars Skovgaard

2013-01-01

Noise is the main obstacle for the realization of fault-tolerant quantum information processing and secure communication over long distances. In this work, we propose a communication protocol relying on simple linear optics that optimally protects quantum states from non-Markovian or correlated...... noise. We implement the protocol experimentally and demonstrate the near-ideal protection of coherent and entangled states in an extremely noisy channel. Since all real-life channels are exhibiting pronounced non-Markovian behavior, the proposed protocol will have immediate implications in improving...... the performance of various quantum information protocols....

Oral Manifestations in Pediatric Patients with Coeliac Disease – A Review Article

Science.gov (United States)

Macho, Viviana Marisa Pereira; Coelho, Ana Sofia; Veloso e Silva, Diana Maria; de Andrade, David José Casimiro

2017-01-01

Background: Coeliac disease is a chronic enteropathy that remains a challenge for the clinician, due to its atypical manifestations and etiopathogenic complexity. Objective: This article intends to describe the oral characteristics of Coeliac Disease in children in order to facilitate their management in the dental office. Methods: A review of the literature was performed electronically in PubMed (PubMed Central, and MEDLINE) for articles published in English from 2000 to April of 2017. The article is also based on the authors' clinical experience with children with coeliac disease. The searched keywords were “coeliac disease “,”oral manifestations “, “dental enamel defects”, “recurrent aphthous stomatitis” and “oral aphthous ulcers”. Results: There are some oral manifestations which are strictly related to coeliac disease: dental enamel defects, recurrent aphthous stomatitis, delayed tooth eruption, multiple caries, angular cheilitis, atrophic glossitis, dry mouth and burning tongue. Conclusion: The complete knowledge of the oral manifestations of coeliac disease can trigger an effective change in the quality of life of the patients with this disease. PMID:29238414

Manifestly scale-invariant regularization and quantum effective operators

CERN Document Server

Ghilencea, D.M.

2016-01-01

Scale invariant theories are often used to address the hierarchy problem, however the regularization of their quantum corrections introduces a dimensionful coupling (dimensional regularization) or scale (Pauli-Villars, etc) which break this symmetry explicitly. We show how to avoid this problem and study the implications of a manifestly scale invariant regularization in (classical) scale invariant theories. We use a dilaton-dependent subtraction function $\\mu(\\sigma)$ which after spontaneous breaking of scale symmetry generates the usual DR subtraction scale $\\mu(\\langle\\sigma\\rangle)$. One consequence is that "evanescent" interactions generated by scale invariance of the action in $d=4-2\\epsilon$ (but vanishing in $d=4$), give rise to new, finite quantum corrections. We find a (finite) correction $\\Delta U(\\phi,\\sigma)$ to the one-loop scalar potential for $\\phi$ and $\\sigma$, beyond the Coleman-Weinberg term. $\\Delta U$ is due to an evanescent correction ($\\propto\\epsilon$) to the field-dependent masses (of...

Pulmonary manifestations of systemic lupus erythematosus

Energy Technology Data Exchange (ETDEWEB)

Yang, Kee Hyuk; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Joo, Kyung Bin; Hahm, Chang Kok; Lee, Seung Ro [College of Medicine, Hanyang Univ., Seoul (Korea, Republic of)

2004-02-01

Pulmonary involvement is more common in systemic lupus erythematosus (SLE) than in any other connective tissue disease, and more than half of patients with SLE suffer from respiratory dysfunction during the course of their illness. Although sepsis and renal disease are the most common causes of death in SLE, lung disease is the predominant manifestation and is an indicator of overall prognosis. Respiratory disease may be due to direct involvement of the lung or as a secondary consequence of the effect of the disease on other organ systems.

Pulmonary manifestations of systemic lupus erythematosus

International Nuclear Information System (INIS)

Yang, Kee Hyuk; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Joo, Kyung Bin; Hahm, Chang Kok; Lee, Seung Ro

2004-01-01

Pulmonary involvement is more common in systemic lupus erythematosus (SLE) than in any other connective tissue disease, and more than half of patients with SLE suffer from respiratory dysfunction during the course of their illness. Although sepsis and renal disease are the most common causes of death in SLE, lung disease is the predominant manifestation and is an indicator of overall prognosis. Respiratory disease may be due to direct involvement of the lung or as a secondary consequence of the effect of the disease on other organ systems

The population and decay evolution of a qubit under the time-convolutionless master equation

International Nuclear Information System (INIS)

Huang Jiang; Fang Mao-Fa; Liu Xiang

2012-01-01

We consider the population and decay of a qubit under the electromagnetic environment. Employing the time-convolutionless master equation, we investigate the Markovian and non-Markovian behaviour of the corresponding perturbation expansion. The Jaynes-Cummings model on resonance is investigated. Some figures clearly show the different evolution behaviours. The reasons are interpreted in the paper. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

Irreversible work in a thermal medium with colored noise

International Nuclear Information System (INIS)

Ohkuma, Takahiro

2009-01-01

Irreversible work and its fluctuations in a classical system governed by non-Markovian stochastic dynamics are investigated. The production of irreversible work depends not only on the protocol of an operation but also on the details of the non-Markovian memory. We consider a generalized Langevin equation with a memory kernel and derive an expression for the irreversible work in the case of slow operations by carrying out an expansion of this memory kernel in the parameter representing the length of the memory. We apply our formulation to a harmonically trapped system and demonstrate the efficiency of a cycle by evaluating the irreversible work. It is found that a decrease in the irreversible work due to the memory effect can occur for an operation through which the trap is squeezed. The results for this harmonic system are verified exactly in the case that the memory kernel has exponential decay

Irreversible work in a thermal medium with colored noise

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Ohkuma, Takahiro

2009-10-01

Irreversible work and its fluctuations in a classical system governed by non-Markovian stochastic dynamics are investigated. The production of irreversible work depends not only on the protocol of an operation but also on the details of the non-Markovian memory. We consider a generalized Langevin equation with a memory kernel and derive an expression for the irreversible work in the case of slow operations by carrying out an expansion of this memory kernel in the parameter representing the length of the memory. We apply our formulation to a harmonically trapped system and demonstrate the efficiency of a cycle by evaluating the irreversible work. It is found that a decrease in the irreversible work due to the memory effect can occur for an operation through which the trap is squeezed. The results for this harmonic system are verified exactly in the case that the memory kernel has exponential decay.

Revisiting the Molecular Mechanism of Neurological Manifestations in Antiphospholipid Syndrome: Beyond Vascular Damage

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Carecchio, M.; Cantello, R.; Comi, C.

2014-01-01

Antiphospholipid syndrome (APS) is a multiorgan disease often affecting the central nervous system (CNS). Typically, neurological manifestations of APS include thrombosis of cerebral vessels leading to stroke and requiring prompt initiation of treatment with antiplatelet drugs or anticoagulant therapy. In these cases, alterations of the coagulation system at various levels caused by multiple effects of antiphospholipid antibodies (aPL) have been postulated to explain the vascular damage to the CNS in APS. However, several nonvascular neurological manifestations of APS have progressively emerged over the past years. Nonthrombotic, immune-mediated mechanisms altering physiological basal ganglia function have been recently suggested to play a central role in the pathogenesis of these manifestations that include, among others, movement disorders such as chorea and behavioral and cognitive alterations. Similar clinical manifestations have been described in other autoimmune CNS diseases such as anti-NMDAR and anti-VGCK encephalitis, suggesting that the spectrum of immune-mediated basal ganglia disorders is expanding, possibly sharing some pathophysiological mechanisms. In this review, we will focus on thrombotic and nonthrombotic neurological manifestations of APS with particular attention to immune-mediated actions of aPL on the vascular system and the basal ganglia. PMID:24741580

Neuropsychiatric Manifestations of Parkinson`s Disease

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Ana Peixinho

2014-10-01

Full Text Available Parkinson’s disease affects about 1% of the world population older than 65 years. It’s most frequently considered a movement disorder, but the neuropsychiatric manifestations associated with the disease and/or its treatment may be of equal or greater significance in some patients. We will discuss briefly the epidemiology, physiopathology and diagnosis of Parkinson’s disease, highlighting the neuropsychiatric manifestations: depression, anxiety, psychosis, dementia, sleep disorders, dopamine dysregulation syndrome.

A finding in genetic polymorphism analysis study: A case of non-mosaic 47, XXX without manifestations.

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Yang, Xingyi; Ye, Zilan; Zhang, Xiaofang; Wang, Huijun; Liu, Chao

2017-07-01

Trisomy X (47, XXX) is a sex chromosome aneuploidy condition in which females have an extra X chromosome, compared to the 46, XX karyotype in typical females. There is considerable variation in the phenotype, with some individuals very mildly affected and others with more significant physical and psychological features. However, the trisomy X in this case, without any of these phenotype, is rarely reported. Here, we report a case found during DNA sample collection in a study of genetic polymorphism analysis of loci in Chinese ethnic group, of a female with neither laboratory or clinical signs of Triple X syndrome. She was born at her mother's 60years old and her father's 62years old. Advanced maternal age was found acting as a significant risk factor of Triplo-X. Moreover, her child are also born without manifestations of 47, XXX syndrome. Pedigree study demonstrated the normal karyotype of the children. A diagnosis of 47XXX was made on the basis of a chromosomal study. Therefore, laboratory investigations (including PCR amplification, more than two kinds of X-STR genotyping, G-banding karyotyping analysis and Pedigree study) are applied to rule out the possibility of Mosaicism (45, X0/47, XXX) and ascertain her 47XXX karyotype without mosaic. The objective of this study was to report a case of trisomy X, diagnostic investigation and management of the case, and to analysis the genetically possible reasons behind the case. To our knowledge, this case is a rare one, found in DNA sample collection for the estimation of gene frequency in the process of genetic polymorphism study, of non-mosaic 47, XXX without signs of physical syndrome and born healthy children. In this study, it revealed that the proportion of trisomy X would be more than official statistics and risk of systemic disabilities is lower than estimated. Moreover, we found out that sample mixture and mosaicism act as the interference factors in forensic test. Therefore, we draw the conclusion that

Can dentists detect multiple myeloma through oral manifestations?

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Thaís Miranda Xavier de Almeida

2018-01-01

Full Text Available Objective: To review published data on oral manifestations of multiple myeloma. Methods: An electronic database search was performed of articles published from 1971 to November 2016 in order to identify studies that reported oral manifestations of patients with multiple myeloma. Case reports and case series with oral manifestations of multiple myeloma in English were included in the study. An additional search was performed of the references of the selected articles. Results: Thirty-seven articles that reported 81 patients with oral manifestations of multiple myeloma were selected: 30 case reports (82% and seven case series (18%. The most common clinical features in the dental cavity were swelling (65.4%, bone pain (33.3%, paresthesia (27.1% and amyloidosis lesions (11.1%. Osteolytic lesions detected on imaging exams were reported in the majority of the patients (90.1% as plasmacytomas or ‘punched-out’ lesions. Conclusions: Swelling and osteolytic lesions represent the most common clinical and radiographic signs of the jaws relating to multiple myeloma, respectively. Keywords: Multiple Myeloma, Oral Manifestations, Mouth, Jaws

Manifestations of Indirect Self-Destructiveness and Dimensions of Emotional Intelligence.

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Tsirigotis, Konstantinos; Łuczak, Joanna

2016-09-01

While indirect self-destructiveness exerts a rather negative influence on the life and psychological and social functioning of the individual, emotional intelligence may have a favourable effect. The aim of this study has been to explore possible relationships between manifestations of indirect self-destructiveness and dimensions of emotional intelligence. A population of 260 individuals (130 females and 130 males) aged 20-30 (mean age of 24.5) was studied by using the Polish version of the Chronic Self-Destructiveness Scale and INTE, i.e., the Polish version of the Assessing Emotions Scale. Manifestations of indirect self-destructiveness show many significant correlations with variables of the INTE, and those correlations are negative. Generally, it can be said that low emotional intelligence is associated with poor psychosocial and social functioning, which, in turn, is associated with indirect self-destructiveness and its manifestations. It seems advisable to use emotional intelligence in the prophylactic and therapeutic work with individuals suffering from various types of disorders, especially the syndrome of indirect self-destructiveness.

Neurocysticercosis, unusual manifestations

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David López-Valencia

2016-07-01

The case of a patient with an atypical location of the parasite at the medulla oblongata, between parenchymal and spinal areas, is presented. The initial symptoms were common but its subsequent manifestations were similar to those of Bruns syndrome. Furthermore, the epidemiological profile of neurocysticercosis in Colombia, its control measures and prevention strategies were reviewed in this study.

Health impact of supplying safe drinking water on patients having various clinical manifestations of fluorosis in an endemic village of West Bengal

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Kunal K Majumdar

2013-01-01

Full Text Available Background: Excessive fluoride in drinking water causes dental, skeletal and non-skeletal fluorosis which is encountered in endemic proportions in several parts of the world. The World Health Organization (WHO guideline value and the permissible limit of fluoride as per the Bureau of Indian Standards (BIS is 1.5 mg/L. Studies showed that withdrawal of sources identified for fluoride, often leads to reduction of fluoride in the body fluids (re-testing urine and serum after a week or ten days and results in the disappearance of non-skeletal fluorosis within a short duration of 10-15 days. Objective: To determine the prevalence of signs and symptoms of suspected dental, skeletal and non-skeletal fluorosis along with food habits, addictions and use of fluoride-containing toothpaste among participants taking water with fluoride concentration above permissible limit and to assess the changes in clinical manifestations of the above participants after consumption of safe drinking water with fluoride concentration below permissible limit. Materials and Methods: A longitudinal intervention study was conducted from October 2010 to December 2011 in a village selected randomly in Purulia District of West Bengal which is endemic for fluorosis. Thirty-six families with 104 family members in the above village having history of taking unsafe water containing high level of fluoride were selected for the study. The occurrence of various dental, skeletal and non-skeletal manifestations of fluorosis along with food habits, addictions and use of fluoride-containing toothpaste among the study population was assessed; the impact of taking safe water with fluoride concentration below permissible limit from a supplied community filter on these clinical manifestations was studied by follow-up examination of the above participants for six months. The data obtained is compared with the collected data from the baseline survey. Results: The prevalence of signs and symptoms of