376 research outputs found

    Diagnostics of macroscopic quantum states of Bose-Einstein condensate in double-well potential by nonstationary Josephson effect

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    We propose a method of diagnostic of a degenerate ground state of Bose condensate in a double well potential. The method is based on the study of the one-particle coherent tunneling under switching the time-dependent weak Josephson coupling between the wells. We obtain a simple expression that allows to determine the phase of the condensate and the total number of the particles in the condensate from the relative number of the particles in two wells Δn=n1n2\Delta n =n_1-n_2 measured before the Josephson coupling is switched on and after it is switched off. The specifics of the application of the method in the cases of the external and the internal Josephson effect are discussed.Comment: 3 page

    Continuous measurements in a composite quantum system and possible exchange of information between its parts

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    We study an influence of the continuous measurement in a composite quantum system C on the evolution of the states of its parts. It is shown that the character of the evolution (decoherence or recoherence) depends on the type of the measured quantity and on the initial state of the system. A number of conditions under which the states of the subsystems of C decohere during the measuring process are established. We propose a model of the composite system and specify the observable the measurement of which may result in the recoherence of the state of one of the subsystems of C. In the framework of this model we find the optimal regime for the exchange of information between the parts of C during the measurement. The main characteristics of such a process are computed. We propose a scheme of detection of the recoherence under the measurement in a concrete physical experiment.Comment: 6 page

    Semiclassical quantization of non-Hamiltonian dynamical systems without memory

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    We propose a new method of quantization of a wide class of dynamical systems that originates directly from the equations of motion. The method is based on the correspondence between the classical and the quantum Poisson brackets, postulated by Dirac. This correspondence applied to open (non-Hamiltonian) systems allows one to point out the way of transition from the quantum description based on the Lindblad equation to the dynamical description of their classical analogs by the equations of motion and vice versa. As the examples of using of the method we describe the procedure of the quantization of three widely considered dynamical systems: 1) the harmonic oscillator with friction, 2) the oscillator with a nonlinear damping that simulates the process of the emergence of the limit cycle, and 3) the system of two periodic rotators with a weak interaction that synchronizes their oscillations. We discuss a possible application of the method for a description of quantum fluctuations in Josephson junctions with a strong damping and for the quantization of open magnetic systems with a dissipation and a pumping.Comment: 8 pages, 0 figure

    Are the Same Clinical Risk Factors Relevant for Incident Diabetes Defined by Treatment, Fasting Plasma Glucose, and HbA1c?

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    International audienceOBJECTIVE: To compare incidences and risk factors for diabetes using seven definitions, with combinations of pharmacological treatment, fasting plasma glucose (FPG) ≥7.0 mmol/L, and HbA(1c) ≥6.5%. RESEARCH DESIGN AND METHODS: Participants aged 30-65 years from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort were followed for 9 years. RESULTS: More men had incident diabetes as defined by FPG ≥7.0 mmol/L and/or treatment than by HbA(1c) ≥6.5% and/or treatment: 7.5% (140/1,867) and 5.3% (99/1,874), respectively (P < 0.009); for women incidences were similar: 3.2% (63/1,958) and 3.4% (66/1,954). Known risk factors predicted diabetes for almost all definitions. Among those with incident diabetes by FPG alone versus HbA(1c) alone, there were more men (78 vs. 35%), case patients were 8 years younger, and fewer were alcohol abstainers (12 vs. 35%) (all P < 0.005). A diabetes risk score discriminated well between those with and without incident diabetes for all definitions. CONCLUSIONS: In men, FPG definitions yielded more incident cases of diabetes than HbA(1c) definitions, in contrast with women. An FPG-derived risk score remained relevant for HbA(1c)-defined diabetes

    ОСОБЛИВОСТІ КЛІНІЧНОГО ПЕРЕБІГУ ЗАПАЛЬНИХ ЗАХВОРЮВАНЬ ГЕНІТАЛІЙ НА ТЛІ ВНУТРІШНЬОМАТКОВИХ СПІРАЛЕЙ

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    In the conditions of the course of inflammatory diseases of genitals on bodies of inwardly-uterine spirals. It is established, that long stay in a inwardly-uterine spirals conducts no typical to a course of inflammatory diseases of genitals with occurrence of tumor-like formations which demand operative intervention.В условиях клиники изучено течение воспалительных заболеваний гениталий на фоне внутриматочных спиралей (ВМС). Установлено, что длительное пребывание в матке ВМС ведет к атипичному течению воспалительных заболеваний гениталий с возникновением опухолеподобных образований, которые требуют оперативного вмешательства.В умовах клініки вивчено перебіг запальних захворювань геніталій на тлі внутрішньоматкових спіралей (ВМС). Встановлено, що тривале перебування в матці ВМС веде до атипового перебігу запальних захворювань геніталій з виникненням пухлиноподібних утворень, які вимагають оперативного втручання

    Increases in Waist Circumference and Weight As Predictors of Type 2 Diabetes in Individuals With Impaired Fasting Glucose: Influence of Baseline BMI: Data from the DESIR study

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    OBJECTIVE To evaluate in impaired fasting glucose (IFG) the relative importance of increases in waist circumference and weight on progression to type 2 diabetes. RESEARCH DESIGN AND METHODS The 9-year incidence of diabetes was studied in 979 men and women with baseline IFG, from the Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) cohort. RESULTS Increases in both waist circumference and weight were significantly associated with diabetes incidence. Standardized odds ratios (95% CI) were 1.79 (1.45–2.21) and 1.86 (1.51–2.30), respectively, after controlling for baseline risk factors. The impact of waist circumference increase was greater for BMI &lt;25 kg/m2 (2.40 [1.63–3.52]) than for BMI ≥25 kg/m2 (1.66 [1.28–2.16]) and persisted after adjusting for concurrent changes in either insulinemia or the homeostasis model assessment of insulin resistance index. Weight change had a similar impact in both BMI groups. CONCLUSIONS In individuals with IFG, it is important to monitor and prevent increases in waist circumference, in particular for those with BMI &lt;25 kg/m2

    The Beurling--Malliavin Multiplier Theorem and its analogs for the de Branges spaces

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    Let ω\omega be a non-negative function on R\mathbb{R}. We are looking for a non-zero ff from a given space of entire functions XX satisfying (a)fωor(b)fω.(a) \quad|f|\leq \omega\text{\quad or\quad(b)}\quad |f|\asymp\omega. The classical Beurling--Malliavin Multiplier Theorem corresponds to (a)(a) and the classical Paley--Wiener space as XX. We survey recent results for the case when XX is a de Branges space \he. Numerous answers mainly depend on the behaviour of the phase function of the generating function EE.Comment: Survey, 25 page

    Resonances for "large" ergodic systems in one dimension: a review

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    The present note reviews recent results on resonances for one-dimensional quantum ergodic systems constrained to a large box. We restrict ourselves to one dimensional models in the discrete case. We consider two type of ergodic potentials on the half-axis, periodic potentials and random potentials. For both models, we describe the behavior of the resonances near the real axis for a large typical sample of the potential. In both cases, the linear density of their real parts is given by the density of states of the full ergodic system. While in the periodic case, the resonances distribute on a nice analytic curve (once their imaginary parts are suitably renormalized), In the random case, the resonances (again after suitable renormalization of both the real and imaginary parts) form a two dimensional Poisson cloud

    Nine-year incident diabetes is predicted by fatty liver indices: the French D.E.S.I.R. study

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    <p>Abstract</p> <p>Background</p> <p>Fatty liver is known to be linked with insulin resistance, alcohol intake, diabetes and obesity. Biopsy and even scan-assessed fatty liver are not always feasible in clinical practice. This report evaluates the predictive ability of two recently published markers of fatty liver: the Fatty Liver Index (FLI) and the NAFLD fatty liver score (NAFLD-FLS), for 9-year incident diabetes, in the French general-population cohort: Data from an Epidemiological Study on the Insulin Resistance syndrome (D.E.S.I.R).</p> <p>Methods</p> <p>At baseline, there were 1861 men and 1950 women, non-diabetic, aged 30 to 65 years. Over the follow-up, 203 incident diabetes cases (140 men, 63 women) were identified by diabetes-treatment or fasting plasma glucose ≥ 7.0 mmol/l. The FLI includes: BMI, waist circumference, triglycerides and gamma glutamyl transferase, and the NAFLD-FLS: the metabolic syndrome, diabetes, insulin, alanine aminotransferase, and asparate aminotransferase. Logistic regression was used to determine the odds ratios for incident diabetes associated with categories of the fatty liver indices.</p> <p>Results</p> <p>In comparison to those with a FLI < 20, the age-adjusted odds ratio (95% confidence interval) for diabetes for a FLI ≥ 70 was 9.33 (5.05-17.25) for men and 36.72 (17.12-78.76) for women; these were attenuated to 3.43 (1.61-7.28) and 11.05 (4.09 29.81), after adjusting on baseline glucose, insulin, hypertension, alcohol intake, physical activity, smoking and family antecedents of diabetes; odds ratios increased to 4.71 (1.68-13.16) and 22.77 (6.78-76.44) in those without an excessive alcohol intake. The NAFLD-FLS also predicted incident diabetes, but with odds ratios much lower in women, similar in men.</p> <p>Conclusions</p> <p>These fatty liver indexes are simple clinical tools for evaluating the extent of liver fat and they are predictive of incident diabetes. Physicians should screen for diabetes in patients with fatty liver.</p
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