Ecophysiological and phytochemical response to ozone of wine grape cultivars of Vitis vinifera L.

Vitis vinifera sensitivity to tropospheric ozone (O₃) has been evidenced in several studies. In this work, physiological and metabolic effects of O₃ on two wine cultivars of V. vinifera (i.e. Maturano and San Giuseppe) have been studied. Moreover, chlorogenic acid (CGA) production, in consideration of its importance in the biosynthetic pathway of polyphenols and as antioxidant, has been investigated. Maturano cultivar resulted more sensitive to O₃, as evidenced by the gas exchange reduction at the early stage of treatment, and by the increase in Ci/Ca and the decoupling of net photosynthesis and the stomatal conductance at the end of the treatment. Unexpectedly, O₃ did not activate stilbene production. Ozone induced an early CGA decrease, significantly more consistent in cv. Maturano, and an increase after 8 days, more consistent in cv. S. Giuseppe. These results suggest that CGA could be considered a biochemical marker of O₃-induced stress in V. vinifera.     

MOM-, MEM- and SEM-phenyl selenides as reagents for the protection of alcohols as alkoxymethyl ethers

A simple activation of MOM-, MEM- and SEM-phenyl selenides by iodonium or copper(I) ions in the presence of alcohols to give the corresponding alkoxymethyl ethers is described.     

A Semisynthetic Approach to New Immunoadjuvant Candidates: Site‐Selective Chemical Manipulation of Escherichia coli Monophosphoryl Lipid A

A semisynthetic approach to novel lipid A derivatives from Escherichia coli (E. coli) lipid A is reported. This methodology stands as an alternative to common approaches based exclusively on either total synthesis or extraction from bacterial sources. It relies upon the purification of the lipid A fraction from fed‐batch fermentation of E. coli, followed by its structural modification through tailored, site‐selective chemical reactions. In particular, modification of the lipid pattern and functionalization of the phosphate group as well as of the sole primary hydroxyl group were accomplished, highlighting the unusual reactivity of the molecule. Preliminary investigations of the immunostimulating activity of the new semisynthetic lipid A derivatives show that some of them stand out as promising, new immunoadjuvant candidates.     

Nonlinear models of vehicular traffic flow – new frameworks of the mathematical kinetic theory

This paper deals with the design of mathematical frameworks for the modeling of traffic flow phenomena by suitable developments of classical models of the kinetic theory. Various types of evolution equations are deduced, and different mathematical structures are proposed toward conceivable applications. To cite this article: M. Delitala, C. R. Mecanique 331 (2003).     

Asymmetric Equilibrium Configurations of Symmetrically Loaded Isotropic Square Membranes

The homogeneous deformations provided by the equilibrium problem of nonlinear isotropic hyperelastic symmetrically loaded membranes are analyzed. Besides the universal symmetric solutions, the problem considered, depending on the form of the stored energy function, may admit asymmetric solutions. For general incompressible materials, the mathematical conditions governing the global development of these asymmetric solutions are investigated. Explicit expressions for evaluating critical loads and bifurcation points are derived. Results and basic relations obtained for general isotropic materials are then specialized for a Valanis–Landel and an Ogden material. For this last case, which is frequently used to model rubberlike materials, a broad numerical analysis was performed. The more qualitatively interesting branches of asymmetric equilibria are shown and the influence of the material parameters is discussed. Finally, using the energy criterion a number of considerations are made on stability. This revised version was published online in July 2006 with corrections to the Cover Date.     

Flexural-torsional bifurcations of a cantilever beam under potential and circulatory forces II. Post-critical analysis

The post-critical behavior of a cantilever beam with rectangular cross-section, under simultaneous action of conservative and non-conservative loads, is analyzed. An internally constrained Cosserat rod model is adopted to describe the dynamics of the beam in finite displacement regime. The bifurcation equations for simple buckling (divergence), simple flutter (Hopf) and double-zero (Takens-Bogdanova-Arnold) bifurcations are derived by means of the multiple time scales method. Due to the nilpotent eigenvalue at the double-zero critical point, the evaluation of the generalized Keldysh's eigenfunctions is required. Finally, some numerical results are shown and the bifurcation scenario of the beam is discussed.     

The Terminal-Oriented Ship Stowage Planning Problem

The Ship Stowage Planning Problem is the problem of determining the optimal position of containers to be stowed in a containership. In this paper we address the problem considering the objectives of the terminal management that are mainly related to the yard and transport operations. We propose a Binary Integer Program and a two-step heuristic algorithm. An extensive computational experience shows the efficiency and effectiveness of our approach. A classification scheme for stowage planning problems is also provided.