Recording and interpreting earthquake response of fullscale structures

Earthquake resistant design (or retrofit) of structures requires realistic and accurate physical and theoretical models. Validation and further improvement of these models can be done only by comparison with full-scale, in situ measurements of the response to earthquake excitation. This paper presents (a) a review of the principles this validation process is based on, (b) discussion of selected examples of past contributions to modeling of structures, and (c) an outline of some of the current research needs. It is concluded that, in the education of future engineers, the art of modeling full-scale structures, and breadth of knowledge in classical mechanics have been neglected, and that this trend should be reversed. 1

Site-specific uniform hazard spectrum in Eastern Turkey based on simulated ground motions including near-field directivity and detailed site effects

In this study, stochastic earthquake catalog of the Erzincan region in Turkey is generated based on synthetic ground motions. Monte Carlo simulation method is used to identify the spatial and temporal distribution of events. Ground motion time histories are generated using stochastic simulation methodology. Annual exceedance rate of each ground motion amplitude is calculated through statistical distribution of the complete set of ground motions. The results are compared with classical probabilistic seismic hazard analysis (PSHA). Classical PSHA generally produces larger spectral amplitudes than the proposed study due to wide range of aleatory variability. The effects of near-field forward directivity and detailed site response are also investigated on the results

Genome Evolution in Outcrossing vs. Selfing vs. Asexual Species

International audienceA major current molecular evolution challenge is to link comparative genomic patterns to species' biology and ecology. Breeding systems are pivotal because they affect many population genetic processes and thus genome evolution. We review theoretical predictions and empirical evidence about molecular evolutionary processes under three distinct breeding systems-outcrossing, selfing, and asexuality. Breeding systems may have a profound impact on genome evolution, including molecular evolutionary rates, base composition, genomic conflict, and possibly genome size. We present and discuss the similarities and differences between the effects of selfing and clonality. In reverse, comparative and population genomic data and approaches help revisiting old questions on the long-term evolution of breeding systems