Antibacterial Mode of Action of the Daucus carota Essential Oil Active Compounds against Campylobacter jejuni and Efflux-Mediated Drug Resistance in Gram-Negative Bacteria

Today, an alarming rise of bacterial gastroenteritis in humans resulting from consuming Campylobacter-tainted foods is being observed. One of the solutions for mitigating this issue may be the antibacterial activity of essential oils. In the present research, we propose to study the antibacterial activity against Campylobacter and other Gram-negative bacteria of Daucus carota essential oil and its active molecules. In addition, a few chemically synthesized molecules such as (E)-methylisoeugenol, Elemicin, and eugenol were also studied. The results showed that the essential oil itself and its most active component, (E)-methylisoeugenol, exhibited bactericidal effects. Similar effects were detected using purified and chemically synthesized molecules. Also, it was observed that the Daucus carota essential oil and its active molecules affected intracellular potassium and intracellular ATP contents in Campylobacter cells. Inhibition of the membrane bound F_OF₁-ATPase was also observed. Eventually, for the first time, the efflux mechanism of active molecules of Daucus carota essential oil was also identified in gamma proteobacteria and its specific antibacterial activity against Campylobacter jejuni was associated with the lack of this efflux mechanism in this species.     

A Reduced-order Photo-chemical Air Quality Model

We report on a reduced-order photo-chemical model (TAPOM-Lite) designed for calculating ozone levels for varying urban scenarios and calibrated for the city of Geneva, Switzerland. The TAPOM-Lite model is an atmospheric-environmental model designed to be incorporated into a larger energy-economy-environment (E 3) model and run in an optimization framework. The motivation for the TAPOM-Lite model was the design of a fast ozone calculator needed for the CPU intensive optimization environment where many iterations are potentially required before a best solution is found. Three principal advances in this model are (1) a simplified chemical scheme for O 3 production, (2) linearization of the O 3 production function needed for the overseeing linear optimization program, and (3) the extraction of gradient (sensitivity) information calculated from the O 3 production function which in turn is needed as “directional” information in the optimization method. Results show that the TAPOM-Lite model is consistent with the full-scale TAPOM model throughout the optimization/iteration process. The TAPOM-Lite model provides a first coupled energy-economy-environment (E 3) program for optimization and also provides a framework for global applications, for example, the linking of global indicators (e.g. mean temperatures) and world energy consumption.     

A Geometric Theory of Nonlinear Morphoelastic Shells

Many thin three-dimensional elastic bodies can be reduced to elastic shells: two-dimensional elastic bodies whose reference shape is not necessarily flat. More generally, morphoelastic shells are elastic shells that can remodel and grow in time. These idealized objects are suitable models for many physical, engineering, and biological systems. Here, we formulate a general geometric theory of nonlinear morphoelastic shells that describes both the evolution of the body shape, viewed as an orientable surface, as well as its intrinsic material properties such as its reference curvatures. In this geometric theory, bulk growth is modeled using an evolving referential configuration for the shell, the so-called material manifold. Geometric quantities attached to the surface, such as the first and second fundamental forms, are obtained from the metric of the three-dimensional body and its evolution. The governing dynamical equations for the body are obtained from variational consideration by assuming that both fundamental forms on the material manifold are dynamical variables in a Lagrangian field theory. In the case where growth can be modeled by a Rayleigh potential, we also obtain the governing equations for growth in the form of kinetic equations coupling the evolution of the first and the second fundamental forms with the state of stress of the shell. We apply these ideas to obtain stress-free growth fields of a planar sheet, the time evolution of a morphoelastic circular cylindrical shell subject to time-dependent internal pressure, and the residual stress of a morphoelastic planar circular shell.     

Existence of Strong Solutions for a Fully Hyperbolic Phase-Field Model Based on Type III Heat Conduction with a Logarithmic Nonlinear Term

In this paper, we prove the existence (and also the uniqueness) of strong solutions for a fully hyperbolic phase-field model based on type III heat conduction. The model consists of the hyperbolic relaxation of the usual equation for the temperature, coupled with the equation for the thermal displacement variable. We also study the limit problem, as the relaxation parameter goes to 0.     

S-Adapted Oligopoly Equilibria and Approximations in Stochastic Variational Inequalities

This paper deals with a class of dynamic games that are used for modelling oligopolistic competition in discrete time with random disturbances that can be described as an event tree with exogenously given probabilities. The concepts of S-adapted information structure and S-adapted equilibrium are reviewed and a characterization of the equilibrium as the solution of a variational inequality (VI) is proposed. Conditions for existence and uniqueness of the equilibrium are provided. In order to deal with the large dimension of the VI an approximation method is proposed which is based on the use of random sampling of scenarios in the event tree. A proof of convergence is provided and these results are illustrated numerically on two dynamic oligopoly models.     

Semiclassical dynamics of Dirac particles interacting with a static gravitational field

The semiclassical limit for Dirac particles interacting with a static gravitational field is investigated. A Foldy–Wouthuysen transformation which diagonalizes at the semiclassical order the Dirac equation for an arbitrary static spacetime metric is realized. In this representation the Hamiltonian provides for a coupling between spin and gravity through the torsion of the gravitational field. In the specific case of a symmetric gravitational field we retrieve the Hamiltonian previously found by other authors. But our formalism provides for another effect, namely, the spin hall effect, which was not predicted before in this context.     

Quantum gravity boundary terms from the spectral action of noncommutative space

We study the boundary terms of the spectral action of the noncommutative space, defined by the spectral triple dictated by the physical spectrum of the standard model, unifying gravity with all other fundamental interactions. We prove that the spectral action predicts uniquely the gravitational boundary term required for consistency of quantum gravity with the correct sign and coefficient. This is a remarkable result given the lack of freedom in the spectral action to tune this term.