Tuning the range of spatial coupling in electrochemical systems: From local via nonlocal to global coupling

A specific feature of pattern formation in electrochemical systems is the occurrence of accelerated fronts; they can be attributed to long-range spatial coupling. In this paper we demonstrate that different coupling functions can be realized by tuning easily accessible parameters: The range of the coupling crucially depends on the length scales of the system, and the strength of the coupling is proportional to the conductivity of the electrolyte. Simulations in the bistable regime are presented which illustrate how the front behavior changes qualitatively when length scales or conductivity are varied

Une tumeur maligne des gaines des nerfs périphériques compliquant la maladie de Von Recklinghausen

Les tumeurs malignes des gaines des nerfs périphériques ou MPNST (Malign Peripheral Nerve Sheath Tumors selon les anglo-saxons) sont des tumeurs rares qui constituent la principale complication des neurofibromatoses de type 1 (NF1) à l'âge adulte. Du fait de leur rareté ces tumeurs posent à la fois des problèmes diagnostiques et thérapeutiques. Nous rapportons une nouvelle observation de MPNST survenue chez une patiente suivie pour une NF1 et dont le traitement a consisté en une exérèse large suivi d'une radiothérapie. Le but de ce travail est d'étudier les critères diagnostiques ainsi que la prise en charge thérapeutique de ce type de tumeurs

Feasibility-Guided Safety-Aware Model Predictive Control for Jump Markov Linear Systems

In this paper, we present a framework that synthesizes maximally safe control policies for Jump Markov Linear Systems subject to stochastic mode switches. Our approach builds on safe and robust methods for Model Predictive Control (MPC), but in contrast to existing approaches that either optimize without regard to feasibility or utilize soft constraints that increase computational requirements, we employ a safe and robust control approach informed by the feasibility of the optimization problem. When subject to inaccurate hybrid state estimation, our feasibility-guided MPC algorithm generates a control policy that is maximally robust to uncertainty in the system's modes. Additionally, we formulate the notion of safety guarantees for multiple-model receding horizon control using Control Barrier Functions (CBF) to enforce forward invariance in safety-critical settings. We simulate our approach on a six degree-of-freedom hexacopter under several scenarios to demonstrate the utility of the framework. Results illustrate that the proposed technique of maximizing the robustness horizon, and the use of CBFs for forward-invariance, improve the overall safety and performance of Jump Markov Linear Systems

Breathing Current Domains in Globally Coupled Electrochemical Systems: A Comparison with a Semiconductor Model

Spatio-temporal bifurcations and complex dynamics in globally coupled intrinsically bistable electrochemical systems with an S-shaped current-voltage characteristic under galvanostatic control are studied theoretically on a one-dimensional domain. The results are compared with the dynamics and the bifurcation scenarios occurring in a closely related model which describes pattern formation in semiconductors. Under galvanostatic control both systems are unstable with respect to the formation of stationary large amplitude current domains. The current domains as well as the homogeneous steady state exhibit oscillatory instabilities for slow dynamics of the potential drop across the double layer, or across the semiconductor device, respectively. The interplay of the different instabilities leads to complex spatio-temporal behavior. We find breathing current domains and chaotic spatio-temporal dynamics in the electrochemical system. Comparing these findings with the results obtained earlier for the semiconductor system, we outline bifurcation scenarios leading to complex dynamics in globally coupled bistable systems with subcritical spatial bifurcations.Comment: 13 pages, 11 figures, 70 references, RevTex4 accepted by PRE http://pre.aps.or

Primary hepatoid carcinoma of the ovary: A case report

Primary hepatoid carcinoma of the ovary (HCO) is a very rare type of high-grade invasive malignant ovarian tumor with hepatic differentiation and production of á-fetoprotein (AFP). We describe a 78-year-old Moroccan woman who presented to our hospital with abdominal distension andpurplish nodules infiltrating the para umbilical skin with weight loss and impairment of her performance status. Excisional biopsy of the paraumbilical nodule revealed a cutaneous localization of moderately   differentiated adenocarcinoma and pelvic ultrasonography noted the presence of a tumoral right adnexal mass. The patient underwent an exploratory laparoscopy which found peritoneal carcinomatosis with pelvic adhesions allowing only a peritoneal biopsy. Diagnosis of primary hepatoid carcinoma of the ovary was established on the basis of classic   histopathologic findings, immunohistochemical staining and marked elevation in serum of á-fetoprotein more than the carbohydrate antigen 125. The patient received 3 cycles of chemotherapy based on Carboplatin and Paclitaxel with disease progression. No second line chemotherapy was given because of the drop of patient's performance status to 3. The patient died one month later

A fitter code for Deep Virtual Compton Scattering and Generalized Parton Distributions

We have developped a fitting code based on the leading-twist handbag Deep Virtual Compton Scattering (DVCS) amplitude in order to extract the Generalized Parton Distributions (GPD) information from DVCS observables in the valence region. In a first stage, with simulations and pseudo-data, we show that the full GPD information can be recovered from experimental data if enough observables are measured. If only part of these observables are measured, valuable information can still be extracted, certain observables being particularly sensitive to certain GPDs. In a second stage, we make a practical application of this code to the recent DVCS Jefferson Lab Hall A data from which we can extract numerical constraints for the two $H$ GPD Compton Form Factors.Comment: 15 pages, 8 figure