A characterisation of the embeddings of PG(m,q) into PG(n,qr).

Let S_m be an embedding of PG(m,q) into PG(n,q^r),with n < m, such that S_m generates PG(n,q^r). S_m can be obtained as a projection from a (m–n–1)-dimensional subspace V_m–n–1 into a non incident n-dimensional subspace V_n of some strong embedding S of PG(m,q) into PG(m,q^r).     

A Hybrid Bounding Procedure for the Workload Allocation Problem on Parallel Unrelated Machines with Setups

A nonpreemptive single stage manufacturing process with parallel, unrelated machines and multiple job types with setups (PUMS) is considered. We propose a hybrid approximation procedure where a Lagrangean relaxation dual and a Lagrangean decomposition dual are solved one after the other to generate a good lower bound on the optimal makespan value. Computational results are reported.     

Poly-α-methyleneglutaronitrile. Characteristic features of some anionic polymers

For (initiator)/(monomer) ratios exceeding 10^-3, the anionic polymerization of α-methyleneglutaronitrile in homogeneous solution in DMF (initiated by lithium-naphthalene at -35° or by diphenylmethyl-lithium at -70°) leads to fairly white polymers with yields higher than 75 per cent. Infra-red and u.v. spectrometric studies and flash pyrolysis experiments show that the nitrile functions are involved in the polymerization only to a very small extent. On the other hand, molecular weight and sedimentation measurements and hydrodynamic behaviour of the polymer in DMF solution suggest a broad polydispersity for the samples, and a very high branching density for their higher molecular weight fractions. These characteristic features are to be correlated with those of anionic polyacrylonitrile; they may be tentatively attributed to transfer to polymer at the acidic methylene group a to the nitrile function.     

Etude par correlation de photons de la raie depolarisee dans la glycerine a basse temperature

The depolarized light scattered by glycerol at low temperature has been studied using a digital clipped correlator. The data are fitted to a Cole-Davidson distribution of relaxation times. Comparison of the polarized and depolarized spectra indicates that large step reorientational motions take place. This confirms the results obtained at higher temperature by Pinnow, Candau and Litovitz.     

Catalytic N-sulfonyliminium ion-mediated cyclizations to alpha-vinyl-substituted isoquinolines and beta-carbolines and applications in metathesis

[reaction: see text] Catalytic Sn(OTf)2-induced cyclization of linear, aryl-containing allylic N,O-acetals produced vinyl-substituted tetrahydroisoquinolines and tetrahydro-1H-beta-carbolines. The usefulness of the vinyl moiety in the resulting products was demonstrated via the synthesis of various key building blocks for alkaloid structures. The alpha-vinyl moiety was utilized in a [2,3] sigmatropic rearrangement, in ring-closing metathesis and a cross-metathesis-based synthesis of vincantril, an antianoxia agent, and a synthetic member of the vincamine type natural products.     

195Pt NMR studies on monomer and dimer complexes. Observation of Pt?Pt coupling constants

Various platinum complexes have been studied by ¹⁹⁵Pt FT NMR. Long range J(³¹P¹⁹⁵Pt) and J(¹⁹⁵Pt¹⁹⁵Pt) are observed in dinuclear complexes. The value of ¹J(³¹P¹⁹⁵Pt) in monomeric and dimeric complexes is shown to depend mainly upon the Pt—P bond length.     

Asymptotics for the Low-Lying Eigenstates of the Schrödinger Operator with Magnetic Field near Corners

The Neumann realization for the Schr?dinger operator with magnetic field is considered in a bounded two-dimensional domain with corners. This operator is associated with a small semi-classical parameter h or, equivalently, with a large magnetic field.We investigate the behavior of its eigenpairs as h tends to zero, like in a semi-classical limit. We prove, in the situation where the domain is a polygon and the magnetic field is constant, that the lowest eigenvalues are exponentially close to those of model problems associated with the corners. We approximate the corresponding eigenvectors by linear combinations of functions concentrated in corners at the scale If the domain has curved sides and the magnetic field is smoothly varying, we exhibit a full asymptotics for eigenpairs in powers of Communicated by Christian Gérard Submitted: October 13, 2005 Accepted: December 19, 2005     

Functionally relevant electric-field induced perturbations of the prosthetic group of yeast ferrocytochrome c mutants obtained from a vibronic analysis of low-temperature absorption spectra

We have measured the low temperature (T = 20 K) absorption spectra of the N52A, N52V, N52I, Y67F, and N52AY67F mutants of ferrous Saccharomyces cerevisiae (baker's yeast) cytochrome c. All the bands in the Q0- and Q(v)-band region are split, and the intensity distributions among the split bands are highly asymmetric. The spectra were analyzed by a decomposition into Voigtian profiles. The spectral parameters thus obtained were further analyzed in terms of the vibronic coupling model of Schweitzer-Stenner and Bigman (Schweitzer-Stenner, R.; Bigman, D. J. Phys. Chem. B 2001, 7064-7073) to identify parameters related to electronic and vibronic perturbations of the heme macrocycle. We report that the electronic perturbation is of B(1g) symmetry and reflects the heterogeneity of the electric field at the heme, that is, the difference between the gradients along the perpendicular N-Fe-N axis of the heme core. We found that all the investigated mutations substantially increase this electronic perturbation, so that the spectral properties become similar to those of horse heart cytochrome c. Moreover, the electronic perturbation was found to correlate nonlinearly with the enthalpy changes associated with the reduction of the heme iron. Group theoretical arguments are invoked to propose a simple model which explains how a perturbation of the obtained symmetry can stabilize the reduced state of the heme iron. Finally, vibronic coupling parameters obtained from the analysis of the Q(v)-band region suggest that the investigated mutations decrease the nonplanar deformations of the heme group. This finding was reproduced by a normal mode structural decomposition (NSD) analysis of the N52V and N52VY67F heme conformations obtained from a 1 ns molecular dynamics simulation. We argue that the reduced nonplanarity contributes to the stabilization of the reduced state.