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A simple but accurate method of stability analysis of embankments and slopes is developed to determine the critical earthquake acceleration that is required to bring a mass of soil, bounded by a slip line of any shape and the free surface, to a state of limiting equilibrium. At the same time, the usual factor of safety can be determined. It is based on the principle of limiting equilibrium and the method of slices. Effective stress strength parameters are used. A distribution of internal body forces is found based on a simple assumption. This depends on the geometry of the dam and the sliding surface as well as on the strength of the material. Though a computer is used for the calculations presented in the Paper, it is not essential. As in any solution, the physical acceptability of the complete solution must be checked before accepting the result. It is suggested to use the critical acceleration as a measure of the factors of safety. On a mis au point une méthode simple mais précise pour l'analyse de la stabilité des terrassements et talus, pour déterminer l'accélération sismique critique requise pour amener une masse de sol limitée par une ligne de glissement de forme quelconque et la surface libre, à un état d'équilibre limite. On peut calculer en même temps les coefficients de sécurité habituels. Cette méthode est basée sur le principe de l'équilibre limite et sur la méthode des tranches. On se sert des paramètres de résistance de contrainte effective. On trouve une distribution des forces volumiques internes qui est basée sur une hypothèse simple, dépendant de la géométrie du barrage et de la surface de glissement ainsi que de la résistance du matériau. Bien qu'on se soit servi d'un ordinateur pour résoudre les équations présentées dans cette Communication, on n'en a pas absolument besoin. Comme dans toute solution, le degré de validité physique de la solution complète doit être vérifié avant d'en accepter les résultats. On suggère de se servir de l'accélération critique comme mesure des coefficients de sécurité.

In the design of earth dams and embankments under earthquake loading conditions, displacements offer a better criterion than a factor of safety on shear strength. The displacement depends on shear strength, inertia forces and pore-pressures generated during the earthquake. The model of a rigid block on a plane surface is used to analyse the effect of inertia forces and pore-pressures on the stability of an earth dam or embankment during strong earth-quakes. The study is based on limit equilibrium principles and the material obeys the Mohr-Coulomb failure criterion with effective stresses. It is shown that by using the pore-pressure parameters A and B, the excess pore-pressures generated during an earthquake can be accounted for in the effective stress analysis. It is also shown that displacements during an earthquake can be easily calculated by using simple pulses. Several interesting conclusions are drawn and an example of application of the method to earth dams and embankments is given. Dans le calcul des barrages en terre et des remblais sous l'action des tremblements de terre, les déplacements offrent un meilleur critère qu'un facteur de sécurité sur la résistance à la rupture au cisaillement. Les déplacements dépendent de la réesistance à la rupture au cisaillement, des forces d'inertie et des pressions intersititelles produites pendant le tremblement de terre. Le. modèle d'un bloc rigide sur une surface plane est utilisé pour analyser l'effet des forces d'inertie et des pressions interstitielles sur la stabilité d'un barrage en terre ou d'un remblai pendant de forts tremblements de terre. L'étude est basée sur des principes d'équilibre limite et la matière obéit au critère de rupture Mohr-Coulomb en contraintes effectives. Il est démontré qu'en utilisant les paramètres A et B des pressions interstitielles, l'excès de pression interstitielle produit pendant un tremblement de terre peut être expliqué par l'analyse des contraintes effectives. Il est aussi démontré que les déplacements produits pendant un tremblement de terre peuvent facilement être calculés en utilisant de simples pulsations. Plusieurs conclusions intéressantes sont tirées et on donne un exemple de l'application de la méthode aux barrages en terre, et aux remblais.

Chloroform extract of the aerial parts ofEupatorium adenophorum Spreng was fractionated and examined for growth inhibition. Bioassay-directed fractions of the plant materials afforded three known cadinenes and β-sitosterol. The effects of different fractions as well as isolated cadinenes were determined usingAllium cepa, Raphanus sativus, andCucumis sativus seeds. Three-day exposure to these cadinenes significantly inhibited germination and seedling growth of all three assay seeds. The degree of inhibition was dependent upon seed species and the concentrations of the compounds tested. Cadinene(1) was found to be more inhibitory to the seeds tested and the activity of the cadinene(3) was less than that of(1) and(4).

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The identification of mutations in targeted genes has been significantly simplified by the advent of TILLING (Targeting Induced Local Lesions In Genomes), speeding up the functional genomic analysis of animals and plants. Next-generation sequencing (NGS) is gradually replacing classical TILLING for mutation detection, as it allows the analysis of a large number of amplicons in short durations. The NGS approach was used to identify mutations in a population of Solanum lycopersicum (tomato) that was doubly mutagenized by ethylmethane sulphonate (EMS). Twenty-five genes belonging to carotenoids and folate metabolism were PCR-amplified and screened to identify potentially beneficial alleles. To augment efficiency, the 600-bp amplicons were directly sequenced in a non-overlapping manner in Illumina MiSeq, obviating the need for a fragmentation step before library preparation. A comparison of the different pooling depths revealed that heterozygous mutations could be identified up to 128-fold pooling. An evaluation of six different software programs (camba, crisp, gatk unified genotyper, lofreq, snver and vipr) revealed that no software program was robust enough to predict mutations with high fidelity. Among these, crisp and camba predicted mutations with lower false discovery rates. The false positives were largely eliminated by considering only mutations commonly predicted by two different software programs. The screening of 23.47 Mb of tomato genome yielded 75 predicted mutations, 64 of which were confirmed by Sanger sequencing with an average mutation density of 1/367 Kb. Our results indicate that NGS combined with multiple variant detection tools can reduce false positives and significantly speed up the mutation discovery rate.

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