A new integrated statistical approach to the diagnostic use of two-dimensional maps

Two-dimensional (2-D) electrophoresis is a very useful technique for the analysis of proteins in biological tissues. The complexity of the 2-D maps obtained causes many difficulties in the comparison of different samples. A new method is proposed for comparing different 2-D maps, based on five steps: (i) the digitalisation of the image; (ii) the transformation of the digitalised map in a fuzzy entity, in order to consider the variability of the 2-D electrophoretic separation; (iii) the calculation of a similarity index for each pair of maps; (iv) the analysis by multidimensional scaling of the previously obtained similarity matrix; (v) the analysis by classification or cluster analysis techniques of the resulting map co-ordinates. The method adopted was first tested on some simulated samples in order to evaluate its sensitivity to small changes in the spots position and size. The optimal setting of the method parameters was also investigated. Finally, the method was successfully applied to a series of real samples corresponding to the electrophoretic bidimensional analysis of sera from normal and nicotine-treated rats. Multidimensional scaling allowed the separation of the two classes of samples without any misclassification.     

Simple and immune relations on countable structures

 Let 𝒜 be a computable structure and let R be a new relation on its domain. We establish a necessary and sufficient condition for the existence of a copy ℬ of 𝒜 in which the image of R (?R, resp.) is simple (immune, resp.) relative to ℬ. We also establish, under certain effectiveness conditions on 𝒜 and R, a necessary and sufficient condition for the existence of a computable copy ℬ of 𝒜 in which the image of R (?R, resp.) is simple (immune, resp.). Received: 4 February 2001 Published online: 5 November 2002 RID="*" ID="*" The first three authors gratefully acknowledge support of the NFS Binational Grant DMS-0075899. RID="*" ID="*" The first three authors gratefully acknowledge support of the NFS Binational Grant DMS-0075899. RID="*" ID="*" The first three authors gratefully acknowledge support of the NFS Binational Grant DMS-0075899.     

Trivial, strongly minimal theories are model complete after naming constants

We prove that if is any model of a trivial, strongly minimal theory, then the elementary diagram is a model complete -theory. We conclude that all countable models of a trivial, strongly minimal theory with at least one computable model are -decidable, and that the spectrum of computable models of any trivial, strongly minimal theory is .

     

Lateral mobility of plasma membrane proteins in dividing eggs of the loach (Misgurnus fossilis): Regional differences and changes during the cell cycle

Regional differences in lateral diffusion rates of fluorescence-labeled proteins have been studied in the plasma membrane of dividing eggs of the loach (Misgurnus fossilis) by fluorescence recovery after photobleaching (FRAP). Apparent animal-vegetal differences in fluorescence intensity, lateral diffusion coefficients, and fractions of mobile proteins have been found, with all these quantities being higher in the animal pole region than in the yolk region. Cyclic changes in protein diffusion coefficients and mobile fractions during the first few cell cycles have also been recorded. Soon after the end of a cleavage, the diffusion coefficient reaches its minimal value and increases rapidly before the next cleavage.     

Iminophosphine-palladium(0) complexes as highly active catalysts in the Suzuki reaction. Synthesis of undecaaryl substituted corroles

The iminophosphine-palladium(0) complex [Pd(dmfu)(P-N)] [dmfu=dimethyl fumarate; P-N=2-(PPh₂)C₆H₄-1-CHNC₆H₄-4-OMe] is a very efficient catalyst for the Suzuki coupling. In the reaction of aryl bromides with phenylboronic acid, turnover numbers up to ca. 200,000 are obtained at 110 °C in 2 h. Good rates are obtained also with the sterically hindered and electronically deactivated 2-bromo-1,3,5-trimethylbenzene. The complex is able to catalyze the exhaustive arylation of 2,3,7,8,12,13,17,18-octabromo-5,10,15-triphenylcorroleCu(III) to yield the corresponding undecaaryl substituted derivative.     

Effect of stacking faults on the optical properties of inverted opals

Stacking faults appear to be the most common type of defect in inverted opals which are good candidates for photonic crystals with absolute gaps in the visible range of light. In this Letter we present for the first time a systematic study of the effect of stacking faults on the optical properties of self-assembled photonic crystals, by means of large-scale transmittance calculations for macroscopic slabs of inverted opals with randomly distributed stacking faults. We show that frequency gaps, as seen in optical transmission experiments, will in general appear wider in the presence of stacking faults. We attribute the above to Anderson localization of light due to disorder.     

A restriction theorem for Métivier groups

In the spirit of an earlier result of D. Müller on the Heisenberg group we prove a restriction theorem on a certain class of two step nilpotent Lie groups. Our result extends that of Müller also in the framework of the Heisenberg group.     

Water perturbed by cellophane: comparison of its physicochemical properties with those of water perturbed with cotton wool or Nafion

We present experimental data on water repetitively brought in contact with cellophane. Although this hydrophilic polymer is insoluble in water, repetitively immersing it in water changes the liquid’s properties. We compare the physicochemical properties of the water left over after removing the cellophane to those of previously published data on water repetitively brought in contact with other in water insoluble polymers (cotton wool or Nafion). Some of the properties are similar. All the properties considerably differ from those of the Milli-Q^® water used. On lyophilizing these waters, solid residues remain. The residues are soluble in water. The chemical nature of the residues differs from that of the perturbing polymers.

     

A route to fluorocontaining N,S-heterocycles via octafluoro-2,3-epoxybutane

The reaction of octafluoro-2,3-epoxybutane 1 with 2-aminothiophenol gave three kinds of novel fluorocontaining N,S-heterocyclic compounds depending on the solvent nature: 2,3-bis(trifluoromethyl)-3,4-dihydro-2H-1,4-benzothiazin-2-ol 2, 2-trifluoromethyl-2-[1-(2-aminophenylthio)-2,2,2-trifluoroethyl]-1,3-benzothiazolidine 6 and 5a,11a-bis(trifluoromethyl)-5a,6,11a,12-tetrahydro-5,11-dithia-6,12-diazanaphthacene 5. Use of the toluene, dioxane, tetrahydrofuran, acetonitrile and dimethoxyethane gave the unexpected dihydrobenzothiazine 2 (RS,SR > RR,SS) in good to moderate yields. In dimethylsulfoxide and N,N-dimethylacetamide, unusual cyclization occurred resulting in benzothiazolidine 6 (RS,SR/RR,SS ∼ 1:1) in moderate yields. Formation of minor 1,1,1,3,4,4,4-heptafluoro-3-(2-aminophenylthio)-2,2-dihydroxybutane 4 which was converted into bis(benzothiazine) 5 was observed in all solvents tested with the exception of toluene and dioxane. The molecular structure of the RS,SR-diastereomer of dihydrobenzothiazine 2, bis(benzothiazine) 5 and the RS,SR-diastereomer of benzothiazolidine 6 has been established by X-ray crystallography.