149 research outputs found

    Frenkel-Kontorova model with cold trapped ions

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    We study analytically and numerically the properties of one-dimensional chain of cold ions placed in a periodic potential of optical lattice and global harmonic potential of a trap. In close similarity with the Frenkel-Kontorova model, a transition from sliding to pinned phase takes place with the increase of the optical lattice potential for the density of ions incommensurate with the lattice period. Quantum fluctuations lead to a quantum phase transition and melting of pinned instanton glass phase at large values of dimensional Planck constant. The obtained results are also relevant for a Wigner crystal placed in a periodic potential.Comment: RevTeX, 5 pages, 11 figures, research at http://www.quantware.ups-tlse.f

    Synchronization and bistability of qubit coupled to a driven dissipative oscillator

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    We study numerically the behavior of qubit coupled to a quantum dissipative driven oscillator (resonator). Above a critical coupling strength the qubit rotations become synchronized with the oscillator phase. In the synchronized regime, at certain parameters, the qubit exhibits tunneling between two orientations with a macroscopic change of number of photons in the resonator. The life times in these metastable states can be enormously large. The synchronization leads to a drastic change of qubit radiation spectrum with appearance of narrow lines corresponding to recently observed single artificial-atom lasing [O. Astafiev {\it et al.} Nature {\bf 449}, 588 (2007)].Comment: revtex 4 pages, 6 figs, research at http://www.quantware.ups-tlse.fr

    Quantum correlations and synchronization measures

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    The phenomenon of spontaneous synchronization is universal and only recently advances have been made in the quantum domain. Being synchronization a kind of temporal correlation among systems, it is interesting to understand its connection with other measures of quantum correlations. We review here what is known in the field, putting emphasis on measures and indicators of synchronization which have been proposed in the literature, and comparing their validity for different dynamical systems, highlighting when they give similar insights and when they seem to fail.Comment: book chapter, 18 pages, 7 figures, Fanchini F., Soares Pinto D., Adesso G. (eds) Lectures on General Quantum Correlations and their Applications. Quantum Science and Technology. Springer (2017

    Treatment of iron deficiency in patients after acute decompensation: a new target in the treatment of heart failure

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    Iron deficiency  (ID) is one of the most common  comorbidities  in patients with heart failure (HF). ID is a strong independent predictor of outcomes  in HF patients. ID reduces  quality of life, exercise  tolerance,  and survival in patients with HF, regardless of anemia status. The latest 2021 guidelines recommend  initiating ID treatment at a ferritin <100 ”g/L, or 100 to 299 ”g/L, when transferrin saturation is less than 20%. The FAIR-HF and CONFIRM-HF studies have shown improvements in symptoms,  quality of life, and functional status in patients with stable HF and ID after intravenous administration of ferric carboxymaltose (FCM). Moreover, the results of these studies showed a reduced  risk of hospitalization for HF, which was later confirmed  in a subsequent  meta-analysis. Finally, the AFFIRM-AHF study, which evaluated the effect of FCM administration on outcomes  in patients hospitalized for acute HF/acute decompensated  HF, found a significant reduction in HF-related readmissions among patients treated with FCM

    Wigner crystal in snaked nanochannels

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    We study properties of Wigner crystal in snaked nanochannels and show that they are characterized by conducting sliding phase at low charge densities and insulating pinned phase emerging above a certain critical charge density. The transition between these phases has a devil's staircase structure typical for the Aubry transition in dynamical maps and the Frenkel-Kontorova model. We discuss implications of this phenomenon for charge density waves in quasi-one-dimensional organic conductors and for supercapacitors in nanopore materials.Comment: 4 pages, 6 figs, research at http://www.quantware.ups-tlse.f

    Big Entropy Fluctuations in Statistical Equilibrium: The Macroscopic Kinetics

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    Large entropy fluctuations in an equilibrium steady state of classical mechanics were studied in extensive numerical experiments on a simple 2--freedom strongly chaotic Hamiltonian model described by the modified Arnold cat map. The rise and fall of a large separated fluctuation was shown to be described by the (regular and stable) "macroscopic" kinetics both fast (ballistic) and slow (diffusive). We abandoned a vague problem of "appropriate" initial conditions by observing (in a long run)spontaneous birth and death of arbitrarily big fluctuations for any initial state of our dynamical model. Statistics of the infinite chain of fluctuations, reminiscent to the Poincar\'e recurrences, was shown to be Poissonian. A simple empirical relation for the mean period between the fluctuations (Poincar\'e "cycle") has been found and confirmed in numerical experiments. A new representation of the entropy via the variance of only a few trajectories ("particles") is proposed which greatly facilitates the computation, being at the same time fairly accurate for big fluctuations. The relation of our results to a long standing debates over statistical "irreversibility" and the "time arrow" is briefly discussed too.Comment: Latex 2.09, 26 pages, 6 figure

    Life trajectories of parents who’s parental rights were terminated: the sociological research

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    Life trajectories of parents who’s parental rights were terminated: the sociological research / O. A. Volkova [et al.] // Indo American journal of pharmaceutical sciences. - 2017. - N04(09).-P. 3128-3133. - Refer.: p. 3132-3133.The article presents the results of a sociological research conducted in 2016 in the Belgorod, Saratov regions and the Trans-Baikal Territory and includes two stages. On the first stage there was the expert survey (n=25), where the informants were employees of the guardianship authorities; social services; education, health care and law institution

    Fractal Spin Glass Properties of Low Energy Configurations in the Frenkel-Kontorova chain

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    We study numerically and analytically the classical one-dimensional Frenkel-Kontorova chain in the regime of pinned phase characterized by phonon gap. Our results show the existence of exponentially many static equilibrium configurations which are exponentially close to the energy of the ground state. The energies of these configurations form a fractal quasi-degenerate band structure which is described on the basis of elementary excitations. Contrary to the ground state, the configurations inside these bands are disordered.Comment: revtex, 9 pages, 9 figure

    Effect of dapagliflozin therapy on achieving cardiovascular mortality target indicators in patients with heart failure

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    Aim. To assess the effect of therapy with sodium glucose co-transporter type 2 inhibitor dapagliflozin in patients with heart failure with reduced ejection fraction (CHrEF) on the state cardiovascular mortality target indicators.Material and methods. All adult Russian patients with NYHA class II-IV HFrEF (left ventricular ejection fraction ≀40%) were considered as the target population. The characteristics of patients in the study corresponded to those in the Russian Hospital HF Registry (RUS-HFR). The study suggests that the use of dapagliflozin in addition to standard therapy will be expanded by 10% of the patient population annually in 2022-24. Cardiovascular mortality modeling was performed based on the extrapolation of DAPA-HF study result. The number of deaths that can be prevented was calculated when using dapagliflozin in addition to standard therapy. Further, the contribution of prevented deaths with dapagliflozin therapy to the achievement of federal and regional cardiovascular mortality target indicators (1, 2 and 3 years) was calculated.Results. The use of dapagliflozin in addition to standard therapy for patients with NYHA class II-IV CHrEF with the expansion of dapagliflozin therapy by 10% of the patient population annually will additionally prevent 1729 cardiovascular death in the first year. This will ensure the implementation of cardiovascular mortality target indicators in Russia in 2022 by 11,8%. In the second year, 3769 cardiovascular deaths will be prevented, which will ensure the implementation of target indicators in 2023 by 17,2%. In the third year, 5465 cardiovascular deaths prevented, which will ensure the implementation of implementation of target indicators in 2024 by 18,7%.Conclusion. The use of dapagliflozin in addition to standard therapy for patients with NYHA class II-IV CHrEF will ensure the implementation of implementation of target indicators in 2024 by 18,7%

    Equilibrium Relativistic Mass Distribution for Indistinguishable Events

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    A manifestly covariant relativistic statistical mechanics of the system of NN indistinguishable events with motion in space-time parametrized by an invariant ``historical time'' τ\tau is considered. The relativistic mass distribution for such a system is obtained from the equilibrium solution of the generalized relativistic Boltzmann equation by integration over angular and hyperbolic angular variables. All the characteristic averages are calculated. Expressions for the pressure and the density of events are found and the relativistic equation of state is obtained. The Galilean limit is considered; the theory is shown to pass over to the usual nonrelativistic statistical mechanics of indistinguishable particles.Comment: TAUP-2115-9
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