Presentation of problem: Performance of jitter in discriminating between normal and dysphonic speakers

The data we deal with are acoustic feature values computed from speech signals produced by normal control speakers and speakers suffering from a laryngeal pathology. The problem is (i) to compare the discriminatory performance of a given acoustic feature with other features of the same family; (ii) to compare the performance of corresponding features in studies carried out on corpora which were not identical and which did not contain the same number of speakers; (iii) to express quantitatively the share of laryngeal pathologies which could be detected reliably by acoustic means alone. We propose to accomplish tasks (i) to (iii) by separating pooled control and risk groups on the basis of the acoustic feature values alone and by evaluating the quality of approximation of the original groups so realized. In order to evaluate this quality we compute a merit factor satisfying the following properties: (1) to be independent of the number of speakers contained in the pooled control and risk groups; (2) to increase and decrease linearly with the detection and false alarm rates, respectively; (3) to take on values between 0 (no discrimination at all) and 1 (perfect discrimination). We also address the question of the confidence one may have in the merit factor values so achieved, i.e. we describe a method of computing the probability that a merit factor value might have been realized by chance alone.     

Étude sur le dosage colorimétrique du cuivre au diéthyldithiocarbamate (en milieu sodique)

In the colorimetric determination of copper by sodium diethyldithiocarbamate, the alkaline-tartaric medium prevents the development of the parasitic coloration due to the presence of nickel. The introduction of trilon hah no effect in alkaline medium.     

Discovery of a herbicidal lead using polymer-bound activated esters in generating a combinatorial library of amides and esters

Summary A combinatorial library containing mixtures of amides and esters was prepared through solid-phase chemistry. The advantages of using solid-phase chemistry over solution-phase chemistry to prepare this library are discussed. The library was screened through a high-throughput whole organism herbicidal assay upon which a mixture containing amides was found to have herbicidal activity. Deconvolution of the mixture providedN-(3-benzoylphenyl)-3-(1,1-dimethylethyl)-1-methyl)-1H-pyrazole-5-carboxamide as a herbicidal lead with broadleaf and narrowleaf pre-emergence herbicidal activity as low as 100 g/ha on some weed species. This study represents the first report of an agrochemical discovered using a combinatorial approach. Supplementary Material, comprising experimental procedures for the preparation of resin II and the reaction of II with nucleophiles, GC/MS and LC/MS data for the reaction ofII with morpholine, and a detailed experimental for the preparation of 2 with characterization data, is available upon request.     

Etudes conformationnelles par Résonance Magnetique Nucléaire et variations de températures d'éthanes di- et trisubstitués

In this paper we report the conformational analysis of several di- or trisubstituted ethanes substituted by the following groups: N-dialkly, thioalkyl, alkoxy, N-pyrrolidino, N-benzyl, nitrile or carbomethoxy. Spectra were calculated by a method based on chemical shifts. Relative stabilities of rotamers were discussed in relation to structural parameters (geometrical and electronic).     

Etude variationnelle d'une double perturbation. Application au calcul des constantes de couplage entre spins nucleaires

The calculation of molecular electronic polarizability tensor components is presented in the CNDO approximation using several methods, on one hand a perturbation calculation, on the other hand a variational method. Results obtained on thirty molecules are used to compare these methods and to discuss their usefulness.

     

Iterations of transformations on the unit interval: Approach to a periodic attractor

We consider a transformation of the unit interval which exhibits a stable periodic attractor and whose topological entropy is positive. We show that the dynamics leading to this attractor has a statistical character.