pouet

The Bemisia tabaci (Gennadius) whitefly is a major economically damaging pest of many crops such as tomato (Solanum lycopersicum L.). Pesticides are widely used to control B. tabaci while the use of aromatic plants is an alternative control method. The aim of this study was to assess the B.tabaci repellent effect of wild oregano, Plectranthus amboinicus (Lour.) Spreng, a widespread aromatic plant in the West Indies. We tested three origins of wild oregano, including northern, central, and southern Martinique (French West Indies)...

OBJECTIVE: To identify factors influencing parental decision when a fetal cardiac disease is diagnosed. METHOD: All pregnancies with fetal cardiac abnormalities diagnosed at three academic hospitals of Marseille, France, between 2004 and 2008, were retrospectively studied. The association between maternal and fetal variables (maternal age, parity, ethnicity, gestational age at diagnosis, nuchal translucency, fetal gender, chromosomal and extra cardiac abnormalities, and severity of the cardiopathy) and parental decision was tested using univariate and multivariate statistical methods RESULTS: One hundred eighty-eight cases of fetal cardiac disease were analysed, of which 63 were interrupted pregnancies (IP) and 125 continued pregnancies (CP)...

A holographic interferometer that uses two-wave mixing in a photorefractive (Bi12SiO20) crystal under an applied ac field is described. The interferometer uses a repetitive sequence of separate record and readout times to obtain quasi real-time holographic interferograms of vibrating objects. It is shown that a good signal-to-noise ratio of the interferometer is obtained by turning off the object illumination and the applied ac field during readout of the hologram. The good signal-to-noise ratio of the resulting holographic interferograms enables phase measurement, which allows for quantitative deformation analysis...

Fringe-visibility issues of additive-subtractive phase-modulated (ASPM) electronic speckle pattern interferometry (ESPI) are explored. ASPM ESPI is a three-step method in which additive-speckle images are acquired rapidly in an analog fashion in every frame of a video sequence, a speckle phase modulation is intentionally introduced between frames, and a digital subtraction of consecutive pairs of additive-speckle images is performed. We show that this scheme has the good high-frequency noise immunity associated with additive-ESPI techniques as well as the good fringe visibility associated with subtractive-ESPI techniques...

The in-plane component of the wavefield provides valuable information about media properties from seismology to nondestructive testing. A new compact scanning laser ultrasonic interferometer collects light scattered away from the angle of incidence to provide the absolute ultrasonic displacement for both the out-of-plane and an in-plane components. This new system is tested by measuring the radial and vertical polarization of a Rayleigh wave in an aluminum half-space. The estimated amplitude ratio of the horizontal and vertical displacement agrees well with the theoretical value...

It is shown that the speckle nature of electronic speckle pattern interferometry images can be reduced in quasireal time with the use of only three consecutive video images. By use of additive-subtractive phase modulation processing the technique is essentially insensitive to environmental noise, and distortion of fringes does not occur. By further removing the random speckle phase we show, using speckle statistics, that the number of dark speckles in the resulting fringe pattern is close to zero.

We study the problem of classification of d-dimensional vectors into two classes (one of which is 'pure noise') based on a training sample of size m. The main specific feature is that the dimension d can be very large. We suppose that the difference between the distribution of the population and that of the noise is only in a shift, which is a sparse vector. For Gaussian noise, fixed sample size m, and dimension d that tends to infinity, we obtain the sharp classification boundary, i.e. the necessary and sufficient conditions for the possibility of successful classification...

A better knowledge of colloidal and particulate matter of urban wastewater is necessary for the optimisation of the wastewater treatment. This paper presents a methodology based on the study of each granular fraction (settleable, supracolloidal, colloidal and soluble matter) separated by different techniques of liquid-solid separation and analysed by non specific parameters (chemical oxygen demand, total suspended solids, UV spectra). The application of this methodology to a storm event allows to explain the quality variation observed during this period...

The existence of isosbestic point(s) in a set of UV-visible spectra is rarely exploited for quantitative or qualitative information despite its interest. Indeed, the presence of isosbestic points means a quality and quantity conservation in the global composition of samples with a given relation between the concentration of absorbing compounds or mixtures of compounds. However, in some cases, for example, when a dilution occurs, no isosbestic point appears. This work shows that a simple operation, called normalization, can reveal the existence of hidden isosbestic point(s) (IP*)...

Cyclic oxothiomolybdates containing polyphosphate ions were prepared by simple reactions in aqueous medium of the corresponding polyphosphate ions and the cyclic precursor K(2)I(2)Mo(10)S(10)O(10)(OH)(10)(OH(2))(5).15H(2)O. K(5)[Cl(P(2)O(7)]Mo(12)S(12)O(12)(OH)(12)(H(2)O)(4)].22H(2)O (1) was isolated from concentrated chloride solution (2.5 mol.L(-1)). 1 reveals a remarkable complex containing two different substrates encapsulated in a dodecanuclear ring, a H-bonded Cl(-) ion, and a covalently bonded [P(2)O(7)] group...

The aim of this paper is, from the perspective of improvement of Total Suspended Solids (TSS) measurement by UV spectrophotometry, to study the influence of two pretreatments on the UV responses of urban wastewater (sonication and mechanical grinding). The study of optical properties evolution the different phenomena involved and show mechanical grinding as a potential pre-treatment is prosed. Mechanical grinding is applied to samples characterised by different TSS concentration and particle size distributions in order to test its feasability...

The phenomenon of wastewater sample aging is supposed to be treated with a low temperature autosampler. This work presents two examples of treated wastewater, the quality of which varies with the time of conservation. This evolution may pose some problems with respect to regulation compliance or process control. After the explanation of the mechanisms involved in sample aging, some recommendations are proposed in order to improve the UV off-line measurement of TSS and COD of treated wastewater.

The reaction of ethyl vinyl ether (2 equiv) with 4,6-dinitrobenzofuroxan (DNBF, 1 equiv) in dichloromethane affords a mixture of two diastereomeric dihydrooxazine N-oxide adducts, 5a and 5b, in a 4:1 ratio. Further addition of the enol reagent to this mixture results in a second cycloaddition process with formation of a bis(dihydrooxazine N-oxide) product 6, which can also be obtained directly upon treatment of DNBF with excess ethyl vinyl ether. The observed condensations are accounted for in terms of inverse electron demand Diels-Alder cycloaddition processes between the enol ether dienophile and the heterodienyl moieties of DNBF, constituted first, by the 6-NO(2) group conjugated to the 6,7-double bond and then by the 4-NO(2) group and the 4,5-double bond of the carbocyclic ring...