Straight Line Orbits in Hamiltonian Flows

We investigate periodic straight-line orbits (SLO) in Hamiltonian force fields using both direct and inverse methods. A general theorem is proven for natural Hamiltonians quadratic in the momenta in arbitrary dimension and specialized to two and three dimension. Next we specialize to homogeneous potentials and their superpositions, including the familiar H\'enon-Heiles problem. It is shown that SLO's can exist for arbitrary finite superpositions of $N$-forms. The results are applied to a family of generalized H\'enon-Heiles potentials having discrete rotational symmetry. SLO's are also found for superpositions of these potentials.Comment: laTeX with 6 figure

Clinical and angiographic results of angioplasty with a paclitaxel-eluting stent for unprotected left main coronary artery disease (a study of 101 consecutive patients)

SummaryBackgroundAfter coronary stenting with drug eluting stents, long-term clinical outcome of unprotected left main coronary artery disease is unknown, even large scale registries or randomised trials with coronary artery bypass graft are ongoing.AimsTo report clinical and angiographic results of paclitaxel-eluting stent implantation for left main coronary artery stenosis (a series of 101 consecutive patients).MethodsThis report is a prospective study performed to evaluate the immediate and mid-term clinical and angiographic outcomes of patients undergoing paclitaxel-eluting stent (PES) implantation for unprotected left main coronary artery (LMCA) stenosis.From January 2004 to December 2005, 101 consecutive patients were stented with paclitaxel-eluting stents (the provisional T stenting technique followed by Kissing balloon for distal left main vessel disease).ResultsMean age was 68.9±11.07 years. 73.3% of patients were male. Acute coronary syndrome was present in 65% of patients, of whom 22.8% had ST elevation. Distal left main trunk lesions were present in 87.1% of cases. Three-vessel disease represented 7% of cases. Angiographic success was obtained in 97.03% of patients with an acute gain of 2.18±0.53mm. GPIIbIIIa inhibitors were used in only 8.9% of cases. Hospital stay was 7.6±3.7 days. In-hospital complications were present in 7.9%, with a hospital mortality rate of 2%.At six month follow-up, the rate of target lesion revascularization (TLR) was 3%, and the rate for major adverse cardiac events (MACE) was 8.9%. Angiographic control was performed in 88.1% and a late loss of 0.1mm (0.04–0.2mm) was noted. Re-stenosis occurred in 4 patients (4.5% of cases). 4 patients (4%) died, including 2 from cardiac causes.ConclusionPaclitaxel-eluting stent implantation for unprotected left main coronary disease appears to be safe with high procedural success rate and a low re-stenosis rate at six month-follow-up

Simultaneous Identification of the Diffusion Coefficient and the Potential for the Schr\"odinger Operator with only one Observation

This article is devoted to prove a stability result for two independent coefficients for a Schr\"odinger operator in an unbounded strip. The result is obtained with only one observation on an unbounded subset of the boundary and the data of the solution at a fixed time on the whole domain

Le TOP 12 : comment interpréter les réponses comme des mesures de la capacité de la mémoire collective ?

International audienceIntroduction. Le TOP 12 évalue la mémoire collective au travers d'une série de huit types de questions portant sur le souvenir de la vie de 12 célébrités nommément désignées. La validation de tels tests est souvent envisagée dans le seul but de prédire un critère externe au test (validation externe) ; la validation interne n'est quant à elle que très rarement étudiée. Objectifs. Montrer comment les réponses obtenues peuvent mesurer une seule grandeur hypothétique (appelée aussi construit) : la capacité de la mémoire collective. Méthodes. L'échantillon est composé de 145 sujets (91 témoins, 32 patients présentant une maladie d'Alzheimer, 21 patients ayant un trouble cognitif léger de type amnésique, 1 patient ayant une démence sémantique). Deux étapes sont nécessaires : modéliser les réponses aux items à l'aide d'un modèle de réponse à l'item à trois paramètres et tester l'unidimensionnalité des scores estimés. Résultats. Les huit modèles s'ajustent étroitement aux données. L'analyse factorielle confirmatoire ne permet pas de rejeter l'idée selon laquelle les huit types de questions mesurent bien une seule et unique grandeur hypothétique. Conclusion. La modélisation psychométrique des données observées avec le TOP 12 indique qu'elles mesurent la capacité de la mémoire collective. Mots clés : mémoire collective * TOP 12 * validation interne * modélisation psychométrique * grandeur hypothétiqu

A global Carleman estimate in a transmission wave equation and application to a one-measurement inverse problem

We consider a transmission wave equation in two embedded domains in $R^2$, where the speed is $a1 > 0$ in the inner domain and $a2 > 0$ in the outer domain. We prove a global Carleman inequality for this problem under the hypothesis that the inner domain is strictly convex and $a1 > a2$ . As a consequence of this inequality, uniqueness and Lip- schitz stability are obtained for the inverse problem of retrieving a stationary potential for the wave equation with Dirichlet data and discontinuous principal coefficient from a single time-dependent Neumann boundary measurement

Morphological population balance modelling of the effect of crystallisation environment on the evolution of crystal size and shape of para-aminobenzoic acid

A current morphological population balance (MPB) modelling methodology, which integrates crystal morphology, facet growth kinetics with multi-dimensional population balance, is overviewed and demonstrated, hence providing an attractive approach for modelling crystallisation processes. MPB modelling is applied to simulate the batch crystallisation of the alpha-form of para-aminobenzoic acid from ethanolic solutions as a function of the crystallisation environment including cooling rate, seeding temperature and seed conditions (loading, size and shape). The evolution of crystal shape/size and their distributions revealed that higher loading led to smaller and less needle-like crystals with similar yields, hence potentially being an important parameter for process control. Examination of the development of the fracture surface for broken seeds, mimicking the seed conditions after milling in practice in the simulated processes, demonstrated that these faces grew fast and then rapidly disappeared from the external crystal morphology. Restriction and challenges inherent in the current model are also highlighted