4,496 research outputs found
Scaling of Information in Turbulence
We propose a new perspective on Turbulence using Information Theory. We
compute the entropy rate of a turbulent velocity signal and we particularly
focus on its dependence on the scale. We first report how the entropy rate is
able to describe the distribution of information amongst scales, and how one
can use it to isolate the injection, inertial and dissipative ranges, in
perfect agreement with the Batchelor model and with a fBM model. In a second
stage, we design a conditioning procedure in order to finely probe the
asymmetries in the statistics that are responsible for the energy cascade. Our
approach is very generic and can be applied to any multiscale complex system.Comment: in Europhysics Letters, 201
Heat fluctuations for harmonic oscillators
Heat fluctuations of a harmonic oscillator in contact with a thermostat and
driven out of equilibrium by an external deterministic force are studied
experimentally and theoretically within the context of Fluctuation Theorems. We
consider the case of a periodic forcing of the oscillator, and we calculate the
analytic probability density function of heat fluctuations. The limit of large
time is discussed and we show that heat fluctuations satisfy the conventional
fluctuation theorem, even if a different fluctuation relation exists for this
quantity. Experimental results are also given for a transient state.Comment: Submitted to Europhysics Letter
Parental Co‐Construction of 5‐ to 13‐Year‐Olds\u27 Global Self‐Esteem Through Reminiscing About Past Events
The current study explored parental processes associated with children\u27s global self‐esteem development. Eighty 5‐ to 13‐year‐olds and one of their parents provided qualitative and quantitative data through questionnaires, open‐ended questions, and a laboratory‐based reminiscing task. Parents who included more explanations of emotions when writing about the lowest points in their lives were more likely to discuss explanations of emotions experienced in negative past events with their child, which was associated with child attachment security. Attachment was associated with concurrent self‐esteem, which predicted relative increases in self‐esteem 16 months later, on average. Finally, parent support also predicted residual increases in self‐esteem. Findings extend prior research by including younger ages and uncovering a process by which two theoretically relevant parenting behaviors impact self‐esteem development
Hypergeometric solutions to Schr\"odinger equations for the quantum Painlev\'e equations
We consider Schr\"odinger equations for the quantum Painlev\'e equations. We
present hypergeometric solutions of the Schr\"odinger equations for the quantum
Painlev\'e equations, as particular solutions. We also give a representation
theoretic correspondence between Hamiltonians of the Schr\"odinger equations
for the quantum Painlev\'e equations and those of the KZ equation or the
confluent KZ equations.Comment: 17 pages; Journal of Mathematical Physics (Vol.52, Issue 8) 201
Experimental evidence of non-Gaussian fluctuations near a critical point.
submitted to PRLInternational audienceThe orientation fluctuations of the director of a liquid crystal are measured, by a sensitive polarization interferometer, close to the Fréedericksz transition, which is a second order transition driven by an electric field. We show that near the critical value of the field the spatially averaged order parameter has a generalized Gumbel distribution instead of a Gaussian one. The latter is recovered away from the critical point. The relevance of slow modes is pointed out. The parameter of generalized Gumbel is related to the effective number of degrees of freedom
Elementary structural building blocks encountered in silicon surface reconstructions
Driven by the reduction of dangling bonds and the minimization of surface
stress, reconstruction of silicon surfaces leads to a striking diversity of
outcomes. Despite this variety even very elaborate structures are generally
comprised of a small number of structural building blocks. We here identify
important elementary building blocks and discuss their integration into the
structural models as well as their impact on the electronic structure of the
surface
Experimental study of work fluctuations in a harmonic oscillator
The work fluctuations of a harmonic oscillator in contact with a thermostat
and driven out of equilibrium by an external force are studied experimentally.
For the work both the transient and stationary state fluctuation theorems hold.
The finite time corrections are very different from those of a first order
Langevin equation. The heat and work fluctuations are studied when a periodic
forcing is applied to the oscillator. The importance of the choice of the
''good work'' to compute the free energy from the Jarzinsky equality is
discussed
TV-Centric technologies to provide remote areas with two-way satellite broadband access
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Biliary cirrhosis and sepsis are two risk factors of failure after surgical repair of major bile duct injury post-laparoscopic cholecystectomy.
International audienceBACKGROUND: Major bile duct injury (MBDI) remains frequent after laparoscopic cholecystectomy (LC) reaching 0.3 to 0.6 % and is associated with a significant mortality rate. The aim of this study was to retrospectively analyze the factors likely to influence the long-term results of surgical repair for MBDI occurring after LC. METHODS: Medical records of patients referred to our referral center from January 1992 to January 2010 for management of bile duct injury following LC were retrospectively analyzed, and patients with MBDI were identified. Clinicopathological factors likely to influence long-term results after surgical repair were assessed by univariate and multivariable analysis. RESULTS: During the study period, 38 patients were treated for MBDI. These 38 patients underwent Roux-en-Y hepaticojejunostomy (HJ) or HJ revision in 25 (66 %) and 13 (34 %) cases, respectively. The median follow-up period was 93 (26-204) months. A Clavien-Dindo post-operative morbidity class >3 occurred in 10 (26 %) cases and was independently associated with a surgical repair performed during a sepsis period (OR = 102.5; IC 95 % [7.12; 11,352], p < 0.007). Long-term results showed that biliary strictures occurred in 5 (13 %) cases and were associated with sepsis (p < 0.006), liver cirrhosis (p < 0.002) and post-operative complications (p < 0.012). Multivariate analysis revealed that only liver cirrhosis remained predictive of stricture (OR = 26.4, 95 % CI [2; 1,018], p < 0.026). CONCLUSION: When MBDI occurs following LC, HJ seems to be the optimal treatment but should not be performed during a sepsis period. Long-term results are significantly altered by the presence of a biliary cirrhosis at time of repair
Work fluctuation theorems for harmonic oscillators
The work fluctuations of an oscillator in contact with a thermostat and
driven out of equilibrium by an external force are studied experimentally and
theoretically within the context of Fluctuation Theorems (FTs). The oscillator
dynamics is modeled by a second order Langevin equation. Both the transient and
stationary state fluctuation theorems hold and the finite time corrections are
very different from those of a first order Langevin equation. The periodic
forcing of the oscillator is also studied; it presents new and unexpected short
time convergences. Analytical expressions are given in all cases
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