Increasing entanglement between Gaussian states by coherent photon subtraction

We experimentally demonstrate that the entanglement between Gaussian entangled states can be increased by non-Gaussian operations. Coherent subtraction of single photons from Gaussian quadrature-entangled light pulses, created by a non-degenerate parametric amplifier, produces delocalized states with negative Wigner functions and complex structures, more entangled than the initial states in terms of negativity. The experimental results are in very good agreement with the theoretical predictions

Meta-analysis of predictive models to assess the clinical validity and utility for patient-centered medical decision making: application to the CAncer of the Prostate Risk Assessment (CAPRA)

Background: The Cancer of the Prostate Risk Assessment (CAPRA) score was designed and validated several times to predict the biochemical recurrence-free survival after a radical prostatectomy. Our objectives were, first, to study the clinical validity of the CAPRA score, and, second, to assess its clinical utility for stratified medicine from an original patient-centered approach. Methods: We proposed a meta-analysis based on a literature search using MEDLINE. Observed and predicted biochemical-recurrence-free survivals were compared to assess the calibration of the CAPRA score. Discriminative capacities were evaluated by estimating the summary time-dependent ROC curve. The clinical utility of the CAPRA score was evaluated according to the following stratified decisions: active monitoring for low-risk patients, prostatectomy for intermediate-risk patients, or radio-hormonal therapy for high risk patients. For this purpose, we assessed CAPRA’s clinical utility in terms of its ability to maximize time-dependent utility functions (i.e. Quality-Adjusted Life-Years – QALYs). Results: We identified 683 manuscripts and finally retained 9 studies. We reported good discriminative capacities with an area under the SROCt curve at 0.73 [95%CI from 0.67 to 0.79], while graphical calibration seemed acceptable. Nevertheless, we also described that the CAPRA score was unable to discriminate between the three medical alternatives, i.e. it did not allow an increase in the number of life years in perfect health (QALYs) of patients with prostate cancer. Conclusions: We confirmed the prognostic capacities of the CAPRA score. In contrast, we were not able to demonstrate its clinical usefulness for stratified medicine from a patient-centered perspective. Our results also highlighted the confusion between clinical validity and utility. This distinction should be better considered in order to develop predictive tools useful in practice

Rheological Changes After Stenting of a Cerebral Aneurysm: A Finite Element Modeling Approach

Hemodynamic changes in intracranial aneurysms after stent placement include the appearance of areas with stagnant flow and low shear rates. We investigated the influence of stent placement on blood flow velocity and wall shear stress of an intracranial aneurysm using a finite element modeling approach. To assess viscosity changes induced by stent placement, the rheology of blood as non-Newtonian fluid was taken into account in this model. A two-dimensional model with a parent artery, a smaller branching artery, and an aneurysm located at the bifurcation, before and after stent placement, was used for simulation. Flow velocity plots and wall shear stress before and after stent placement was calculated over the entire cardiac circle. Values for dynamic viscosity were calculated with a constitutive equation that was based on experimental studies and yielded a viscosity, which decreases as the shear rate increases. Stent placement lowered peak velocities in the main vortex of the aneurysm by a factor of at least 4 compared to peak velocities in the main artery, and it considerably decreased the wall shear stress of the aneurysm. Dynamic viscosity increases after stent placement persisted over a major part of the cardiac cycle, with a factor of up to 10, most pronounced near the dome of the aneurysm. Finite element modeling can offer insight into rheological changes induced by stent treatment of aneurysms and allows visualizing dynamic viscosity changes induced by stent placemen

Une méthode de détermination indirecte de la rhéologie d'un fluide en écoulement par des mesures de profils de vitesse

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Local mass transport and mechanical stimuli generated with perfused porous scaffold

proceeding p 2

Approche numérique des écoulements sanguins maternels dans le placenta humain

Tout au long de la grossesse, le développement et la croissance du fœtus dépendent de la vascularisation du placenta par le sang de la mère. L’objectif de ce travail est de permettre une meilleure compréhension de la physiopathologie de la circulation utéroplacentaire, l’outil numérique permettant d’atteindre des grandeurs habituellement non accessibles pour des raisons éthiques ou de spécificité d’espèce. On présente une première approche simplifiée qui démontre la nécessité de prendre en compte les propriétés rhéologiques du sang pour l'étude des écoulements sanguins dans la chambre intervilleuse

Dynamics of a pulsed continuous variable quantum memory

6 pages, 5 figuresInternational audienceWe study the transfer dynamics of non-classical fluctuations of light to the ground-state collective spin components of an atomic ensemble during a pulsed quantum memory sequence, and evaluate the relevant physical quantities to be measured in order to characterize such a quantum memory. We show in particular that the fluctuations stored into the atoms are emitted in temporal modes which are always different than those of the readout pulse, but which can nevertheless be retrieved efficiently using a suitable temporal mode-matching technique. We give a simple toy model - a cavity with variable transmission - which accounts for the behavior of the atomic quantum memory

Approche numérique des écoulements maternels dans le placenta humain

During the pregnancy, the development and the foetal growth depend on the placental vascularization by the maternal blood. The aim of this study is to achieve a better understanding of uteroplacental circulation physiopathology, the CFD enables us to reach information, usually inaccessible for ethical reasons or species specificity. We show a first simplified approach which prouves the necessity of taking into consideration the blood rheological properties for the study of blood flows in the intervillous chamber. Numerical Modelisation of the Blood Flows in the Human Placenta’s Intervillous Space.Tout au long de la grossesse, le développement et la croissance du foetus dépendent de la vascularisation du placenta par le sang de la mère. L’objectif de ce travail est de permettre une meilleure compréhension de la physiopathologie de la circulation utéroplacentaire, l’outil numérique permettant d’atteindre des grandeurs habituellement non accessibles pour des raisons éthiques ou de spécificité d’espèce. On présente une première approche simplifiée qui démontre la nécessité de prendre en compte les propriétés rhéologiques du sang pour l'étude des écoulements sanguins dans la chambre intervilleuse.Senouillet Loïc, Dantan Philippe, Flaud Patrice, Guiffant Gérard, Tsatsaris Vassilis. Approche numérique des écoulements maternels dans le placenta humain. In: L'eau et le monde vivant. 28èmes Journées de l'Hydraulique. Congrès de la Société Hydrotechnique de France. Paris, 12 et 13 octobre 2004. 2004