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Laala S.,Center National Of Controle Et Of Certification Des Semences Et Plants | Bouznad Z.,ensa Inc | Manceau C.,Laboratoire Of La Sante Des Vegetaux
European Journal of Plant Pathology | Year: 2015

Xanthomonas campestris pv. campestris is a seed-borne bacterium that causes black rot on Brassicaceae. Ensuring seed lot sanitary quality is the most efficient control strategy against bacterial diseases. Currently, the procedures adopted in the control of seed lots are mainly based on microbiological techniques combined with PCR or plant inoculation which is time and money consuming. The aim of this study was to propose a reliable and rapid detection technique of living X. c. pv. campestris in cabbage seeds. We have shown that not all cells of X. campestris is able to grown on rich medium after washing and soaking seeds as no colony of X. campestris was detected on inoculated seeds, whereas plantlets develop symptoms 7–14 days after germination. The PCR technique used alone does not address the viability of bacteria in samples. We set up a technique named seed-qPCR for the detection of living X. c. pv. campestris bacterial cells in seed lots. This technique is based on an enrichment of bacterial population associated with infected seeds by seed germination coupled with real-time Taq-man PCR after extraction of the target DNA. It is an inexpensive technique that allow the detection of down to 1 contaminated seed among 10 000 healthy seeds. The seed-qPCR method combines an efficient extraction based on bacterial multiplication on seedlings with a sensitive technique qPCR for the detection of bacteria in seed lots. © 2015, Koninklijke Nederlandse Planteziektenkundige Vereniging. Source

Keiser S.,University of Zurich | Keiser S.,ETH Zurich | Siebenmann C.,University of Zurich | Bonne T.C.,University of Zurich | And 3 more authors.
European Journal of Applied Physiology | Year: 2013

Purpose: Hemoglobin mass (Hbmass) is commonly assessed using the CO re-breathing method with the subject in the seated position. This may lead to an underestimation of Hbmass as blood in lower extremity veins while seated may not be tagged with carbon monoxide (CO) during the re-breathing period. Methods: To test this hypothesis, CO re-breathing was performed on four occasions in nine male subjects, twice in the seated position and twice in combination with light cycle ergometer exercise (1 W/kg body-weight) intending to accelerate blood circulation and thereby potentially allowing for a better distribution of CO throughout the circulation as compared to in the seated position. Blood samples were drawn from an antecubital vein and the saphenous magna vein following the re-breathing procedure. Results: In the seated position, CO re-breathing increased the percent carboxyhemoglobin (%HbCO) in the antecubital vein to 8.9 % (7.8-10.7) [median (min-max)], but less (P = 0.017) in the saphenous magna vein [7.8 % (5.0-9.9)]. With exercise, no differences in %HbCO were observed between sampling sites. As a result, CO re-breathing in combination with exercise revealed a ~3 % higher (P = 0.008) Hbmass, i.e., 936 g (757-1,018) as compared to 908 g (718-940) at seated rest. Conclusion: This study suggests an uneven distribution of CO in the circulation if the CO re-breathing procedure is performed at rest in the seated position and therefore can underestimate Hbmass. © 2013 Springer-Verlag Berlin Heidelberg. Source

Elyousfi A.,University Ibn Zohr | Elyousfi A.,ensa Inc
Signal, Image and Video Processing | Year: 2013

The H. 264/AVC video coding standard uses in intraprediction, 9 directional modes for 4 × 4 and 8 × 8 luma blocks, and 4 directional modes for 16 × 16 luma macroblocks, and 8 × 8 chroma blocks. The use of the variable block size and multiple modes in intraprediction makes the intracoding of H. 264/AVC very efficient compared with other compression standards; however, computational complexity is increased significantly. In this paper, we propose a fast mode selection algorithm for intracoding. This algorithm is based on the vector of the block's gravity center whose direction is used to select the best candidate prediction mode for intracoding. On this basis, only a small number of intraprediction modes are chosen for rate distortion optimization (RDO) calculation. Different video sequences are used to test the performance of proposed method. The simulation results show that the proposed algorithm increases significantly the speed of intracoding with negligible loss of peak signal-to-noise ratio quality. © 2011 The Author(s). Source

The paper deals with the professional dynamics of young farmers in Saharan neoagriculture in Algeria, in the case of plasticulture (market gardening under plastic tunnels). Our analysis is based on a survey of 100 farmers in the municipality of El Ghrous (Biskra) and is illuminated by the literature on clusters (geographical concentrations of companies in the same sector) and on the agricultural ladder (a contractual trajectory allowing the accumulation of know-how and various types of capital). These dynamics result from the external benefits of the cluster that has emerged in the sector, and from the divisibility of the factors (water, land, greenhouses, agricultural inputs, and labor) in this type of production, which facilitates the installation of young farmers. Progress up the agricultural ladder should be read in conjunction with the existence of contractual arrangements regarding access to labor, land, and water. Source

Bouri M.,University of Castilla - La Mancha | Bouri M.,ensa Inc | Gurau M.,Technical University Gheorghe Asachi | Salghi R.,ensa Inc | And 4 more authors.
Analytical and Bioanalytical Chemistry | Year: 2012

A magnetic material based on N-methylimidazolium ionic liquid and Fe 3O4 magnetic nanoparticles incorporated in a silica matrix has been used to extract and preconcentrate sulfonylurea herbicides, such as thifensulfuron methyl (TSM), metsulfuron methyl (MSM), triasulfuron (TS), tribenuron methyl (TBM) and primisulfuron methyl (PSM) from polluted water samples, prior to their analysis by capillary liquid chromatography with a diode array detector (DAD). Under the optimum conditions, this method allows the determination of TSM, MSM, TS, TBM and PSM in a linear range between 5 and 100 ng mL-1, with relative standard deviation values lower than 5.3 % (n=10), in all cases. Detection limits ranging between 1.13 and 2.95 ng mL -1 were achieved. The usefulness of the proposed method was demonstrated by the analysis of river water samples, obtaining recoveries higher than 91 %. © 2012 Springer-Verlag. Source

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