Guaranteed Inertia Functions in Dynamical Games.

This paper deals with inertia functions in control theory introduced in Aubin, Bernardo and Saint-Pierre (2004, 2005) and their adaptation to dynamical games. The inertia function associates with any initial state-control pair the smallest of the worst norms over time of the velocities of the controls regulating viable evolutions. For tychastic systems (parameterized systems where the parameters are tyches, disturbances, perturbations, etc.), the palicinesia of a tyche measure the worst norm over time of the velocities of the tyches. The palicinesia function is the largest palicinesia threshold c such that all evolutions with palicinesia smaller than or equal to c are viable. For dynamical games where one parameter is the control and the other one is a tyche (games against nature or robust control), we define the guaranteed inertia function associated with any initial state-control-tyche triple the best of the worst of the norms of the velocities of the controls and of the tyches and study their properties. Viability Characterizations and Hamilton-Jacobi equations of which these inertia and palicinesia functions are solutions are provided.Viability; dynamical games; inertia function; Tychastic systems; palicinesia;

Dynamic Management of Portfolios with Transaction Costs under Tychastic Uncertainty.

We use in this chapter the viability/capturability approach for studying the problem of dynamic valuation and management of a portfolio with transaction costs in the framework of tychastic control systems (or dynamical games against nature) instead of stochastic control systems. Indeed, the very definition of the guaranteed valuation set can be formulated directly in terms of guaranteed viable-capture basin of a dynamical game. Hence, we shall “compute” the guaranteed viable-capture basin and find a formula for the valuation function involving an underlying criterion, use the tangential properties of such basins for proving that the valuation function is a solution to Hamilton-Jacobi-Isaacs partial differential equations. We then derive a dynamical feedback providing an adjustment law regulating the evolution of the portfolios obeying viability constraints until it achieves the given objective in finite time. We shall show that the Pujal—Saint-Pierre viability/capturability algorithm applied to this specific case provides both the valuation function and the associated portfolios.dynamic games; dynamic valuation; tychastic control systems; management of portfolio;

Viabilist and Tychastic Approaches to Guaranteed ALM Problem.

This study reconsiders the problem of hedging a liability by a portfolio made of a riskless asset and an underlying (underlying).Asset and Liability Management; Viability theory;

Modeling of liming in acid agricultural soils of Libreville (Gabon)

Soil acidification is an ongoing natural process which can be enhanced by human activities or can be controlled by appropriate soil management practices. Two highly acidified urban garden soils, CHA and NTO, were subjected to single-extraction procedure by water to determine the extractable concentrations of Ca, Mg, K, Na, Al, Cu, Fe, Mn, Pb, Zn and . A modeling of effects of liming on soil solution was carried out from initial pH to pH 8.0 using the PHREEQC-2 code coupled with the PHREEQC.dat thermodynamic database. In NTO soil solution, liming increased the concentration of all cations, exception of Al when in CHA soil solution concentration of Ca, Cu, Fe and Pb increased. The chemical speciation of cations was evaluated in the soil solution. Basic cations Ca, Mg, K and Na were found as free forms (Ca2+, Mg2+, K+, Na+) and sometimes complexed by sulfate (,). The concentration of the toxic free ion Al3+ decreased quickly and was replaced by less toxic hydroxide complexes. For the other metals, relative to the total soluble metal concentrations the amounts of free Cu2+ (1%-99%) and Zn2+ (74%-97%) were not different in soil solutions when the amounts of free Pb2+ (10%-93%) and Fe2+ (65%-98%) in NTO soil solution were generally higher than those of CHA soil solution (8%-34% and 43%-84%, respectively). Statistical correlation analysis used to predict the change occurred in the concentration of the free ion in the soil studied showed significant influence of pH,  and  on Al3+, Fe2+, Pb2+ and Zn2+. Key-words: tropical acid soils, urban garden, liming, modeling, PHREEQC-

Infrared and ultraviolet properties of the Landau gauge quark propagator

We present a current summary of a program to study the quark propagator using lattice QCD. We use the Overlap and ``Asqtad'' quark actions on a number of lattice ensembles to assess systematic errors. We comment on the place of this work amongst studies of QCD Green's functions in other formulations. A preliminary calculation of the running quark mass is presented.Comment: 7 pages, Contribution to LHP03, Cairn

The Escherichia coli Serogroup O1 and O2 Lipopolysaccharides Are Encoded by Multiple O-antigen Gene Clusters

Escherichia coli strains belonging to serogroups O1 and O2 are frequently associated with human infections, especially extra-intestinal infections such as bloodstream infections or urinary tract infections. These strains can be associated with a large array of flagellar antigens. Because of their frequency and clinical importance, a reliable detection of E. coli O1 and O2 strains and also the frequently associated K1 capsule is important for diagnosis and source attribution of E. coli infections in humans and animals. By sequencing the O-antigen clusters of various O1 and O2 strains we showed that the serogroups O1 and O2 are encoded by different sets of O-antigen encoding genes and identified potentially new O-groups. We developed qPCR- assays to detect the various O1 and O2 variants and the K1-encoding gene. These qPCR assays proved to be 100% sensitive and 100% specific and could be valuable tools for the investigations of zoonotic and food-borne infection of humans with O1 and O2 extra-intestinal (ExPEC) or Shiga toxin-producing E. coli (STEC) strains

Precise mapping of the CD95 pre-ligand assembly domain.

International audiencePre-association of CD95 at the plasma membrane is mandatory for efficient death receptor signaling. This homotrimerization occurs through self-association of an extracellular domain called the pre-ligand assembly domain (PLAD). Using novel molecular and cellular tools, we confirmed that CD95-PLAD is necessary to promote CD95 multimerization and plays a pivotal role in the transmission of apoptotic signals. However, while a human CD95 mutant deleted of the previously described PLAD domain (amino acids 1 to 66) fails to interact with its wild-type counterpart and trigger autonomous cell death, deletion of amino acids 1 to 42 does not prevent homo- or hetero (human/mouse)-oligomerization of CD95, and thus does not alter transmission of the apoptotic signal. Overall, these findings indicate that the region between amino acids 43 to 66 corresponds to the minimal motif involved in CD95 homotypic interaction and is necessary to convey an efficient apoptotic signal. Interfering with this PLAD may represent a new therapeutic strategy for altering CD95-induced apoptotic and non-apoptotic signals

How to be the best at sail pumping?

Pumping or flicking1 is often used by sailors to get extra propulsion while sailing (subject to restrictions by the racing rules2). Common unsteady sailing situations, due to crew action (e.g. manoeuver like gybing3) or environment conditions (e.g. pitching in waves4, 5) can be reproduced in tunnel testing with accurate flow and yacht attitude4 control. Repeated pumping generating unsteady effects on aerodynamic forces6 is investigated here with a dynamic trimming system. Results are presented for different apparent wind angles (AWA) to determine the best pumping conditions and better understand the physical mechanisms involved

Performance enhancement of downwind sails due to leading edge flapping: A wind tunnel investigation

This work presents a wind tunnel experimental study on the effect of the leading edge flapping on the aerodynamic performance of a spinnaker. Four J80-class spinnaker models, combining two different assembling structures (panel layout) and two different sail materials are tested at various wind speeds and wind angles in a wind tunnel. Results show that, for the wind angle range the spinnaker is designed for, the sustained periodic flapping of the sail leading edge has a significant benefit on performance, with 10% increase in drive force. In these model-scale tests, the sail structural properties did not show significant differences in performance, but affect the point where flapping sets in: a model with a stiffer material and a cross-cut panel layout starts flapping for a longer sheet length, compared to a lighter cloth and a tri-radial layout. Finally, it is shown that the nondimensional flapping frequency is rather constant 0.4 in the design range of wind angle, but it varies with the wind speed and sail structural properties on a smaller wind angle where the spinnaker is more stretched.FP7 PEOPLE IRSES and COFUN

Inviscid approach for upwind sails aerodynamics. How far can we go?

This work presents a full-scale experimental study of a yacht rig and sails in real upwind sailing conditions and a comparison with Fluid Structure Interaction (FSI) simulations with the ARAVANTI model (Finite Element Method for the structure and Vortex Lattice Method for the fluid). An specific on-board instrumentation system simultaneously measures loads in the rig and sails, sailing data (wind, boat attitude and speed) and the shape of sails in real navigation conditions (flying shape). Flying shape parameters are extracted using the camera-based VSPARS system to characterize the effects of sail trims and to be compared with the results of the simulation. The potential flow solver gives fast and accurate predictions of both the flying shape and the loads in the rig in most conditions. The inviscid approach, commonly used in the early stage of design, must be checked, as in particular cases where the sails are heavily loaded, flow separation is significant and results from a potential flow solver are inaccurate. A new version of the model including the heel angle as an additional degree of freedom in the structural solver enables to detect when the inviscid flow approach overestimates the aerodynamic load. This upgrade improves the utility and reliability of the inviscid flow approach which remains relevant at the early stages of design as it is much more cost-effective than RANS models.Brest Métropole Océane, Région Bretagne and the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement PCOFUND-GA-2013-609102 (PRESTIGE-Campus France