An overview of seismic testing needs in Europe: towards a new advanced experimental facility

n/

A semi-active controller tuning and application to base seismically-isolated structures

International audienceThis paper proposes a modified version of Leitmann and co-authors' classical result on the stabilization of uncertain nonlinear systems. In particular, for usual models of structure dynamics in earthquake engineering it is shown that applying a specific control law drives the state variables into a ball around the origin (arbitrarily chosen) in finite time as long as the radius of the ball is not lower than a limiting value. In addition estimates of this limiting ball radius and the time limit for arbitrary ball radius are provided. The semi-active control thus provides the control designer with interesting design parameters. It is also an attempt to explicitly use pseudoacceleration floor response spectrum as a performance criterion. Though not limited to twodegree- of-freedom structures, this semi-active control is applied to these plant models for simplicity and illustrated through simulations

A robust nonlinear semi-active control for base seismically-isolated structures

This paper proposes a robust nonlinear semi-active control for base seismically-isolated structures. The control is based upon an extension of works of Leitmann et al. on the stabilization of nonlinear systems with uncertain models. For usual models of structure dynamics it is shown that applying a specific control law drives the state variables into a ball of specified radius in finite time. The radius of the ball may be arbitrarily chosen as long as it is not lower than a limiting value. In addition, estimates of this limiting ball radius is provided. The time to reach the ball is also provided. The semi-active control thus provides the control designer with interesting design parameters. The efficacy of proposed semiactive control is illustrated by its application to simple models of structures focusing in particular to the attenuation of excitation transmitted from floor to equipment mounted on them

1st year EFAST annual report

The present report provides information about the activities conducted during the 1st year of the EFAST project. The first chapter is dedicated to describe the inquiries conducted at the beginning of the project and to briefly summarise the main results. The second chapter is dedicated to the first EFAST workshop where some of the leading scientists in the field of earthquake engineering have met to discuss about the need and the technologies related to earthquake engineering. The third chapter contains a state of the art and future direction in seismic testing and simulation. The final chapter is dedicated to describe the preliminary design of the web portal of the future testing facility.JRC.DG.G.5-European laboratory for structural assessmen

Exploring the genetic landscape of breast cancer risk & prognosis

The genetic factors known to be involved in breast cancer risk comprise more than 30 loci. These include the high penetrance early-onset breast cancer genes, BRCA1 and BRCA2, a number of rare cancer syndrome genes and rare genes with more moderate penetrance. A larger group of common variants has more recently been identified through genome-wide association studies. Collectively the breast cancer loci identified to date contribute only -30% of the familial risk. In this study, the most prevalent method of conducting genome-wide analyses - single marker testing - was compared to a composite likelihood approach testing multiple markers at the same time based on the underlying linkage disequilibrium structure. Evidence indicates increased power of detection of variants genome-wide for the latter. In order to increase power of detection, three published genome-wide datasets were combined in a meta-analysis using the composite likelihood approach. Findings demonstrate replication of well-established breast cancer loci [such as FGFR2and 8q24] and identify a novel candidate gene, PIK3AP1, as a highly ranking locus. Additionally, part of this study focused on oestrogen receptor-negative [ER -] breast cancer risk by combining genotypic data from seven case-control cohorts and performing composite likelihood testing. Despite the limited replication of known breast cancer loci, which can be justified by the prior prevalence of oestrogen receptor positive [ER+] studies, a nominally significant locus in lOq24 shows association with the ER- form of the disease. Evidence also suggests alternative adjacent locations for the causal variants of previously reported breast cancer loci, such as COX11 and TOX3 genes. Ultimately, genome-wide marker analysis focused on early-onset breast cancer risk and prognosis revealed the confounding effects of combining data genotyped separately without recalling genotypes based on the raw intensity files. However, the association of rs10749071 with HER2+ [Human Epidermal Growth Factor Receptor 2-positive] early onset breast cancer and rs3764459 with the survival of anthracycline-treated breast tumours replicated in follow-up studies. The novel loci identified need to be further tested in larger independent cohorts before conclusive arguments are drawn.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Agent Agent-Based Agent Based Modeling

Agent-Based Modeling [ABM] constitutes a relatively new computational modeling paradigm, originally derived from the Computer Science and refers to the modeling of various phenomena a

Some aspects of floor spectra of 1DOF nonlinear primary structures

International audienceIn this paper the influence of the nonlinear behaviour of the primary structure on floor spectra is investigated by means of simple models. The general trends of floor spectra for different types of nonlinear behaviour of one degree of freedom (1DOF) primary structure are shown and we point out their common futures and their differences. A special attention is given to the cases of elastoplastic and nonlinear elastic behaviours and methods to determine an equivalent linear oscillator are proposed. The properties (frequency and damping) of this equivalent linear oscillator are quite different from the properties of equivalent linear oscillators commonly considered in practice. In particular, in the case of elastoplastic behaviour, there is no frequency shift and damping is smaller than assumed by other methods commonly used. In the case of nonlinear elastic behaviour, the concept of an equivalent frequency which is a random variable is used. Finally, a design floor spectrum of primary structures, exhibiting energy dissipating nonlinear behaviour is proposed

The genetics of breast cancer: risk factors for disease

Andrew Collins, Ioannis PolitopoulosGenetic Epidemiology and Bioinformatics Research Group, Human Genetics Research Division, Southampton General Hospital, School of Medicine, University of Southampton, Southampton, UKAbstract: The genetic factors known to be involved in breast cancer risk comprise about 30 genes. These include the high-penetrance early-onset breast cancer genes, BRCA1 and BRCA2, a number of rare cancer syndrome genes, and rare genes with more moderate penetrance. A larger group of common variants has more recently been identified through genome-wide association studies. Quite a number of these common variants are mapped to genomic regions without being firmly associated with specific genes. It is thought that most of these variants have gene regulatory functions, but their precise roles in disease susceptibility are not well understood. Common variants account for only a small percentage of the risk of disease because they have low penetrance. Collectively, the breast cancer genes identified to date contribute only ~30% of the familial risk. Therefore, there is much interest in accounting for the missing heritability, and possible sources include loss of information through ignoring phenotype heterogeneity (disease subtypes have genetic differences), gene–gene and gene–environment interaction, and rarer forms of variation. Identification of these rarer variations in coding regions is now feasible and cost effective through exome sequencing, which has already identified high-penetrance variants for some rare diseases. Targeting more ‘extreme’ breast cancer phenotypes, particularly cases with early-onset disease, a strong family history (not accounted for by BRCA mutations), and with specific tumor subtypes, provides a route to progress using next-generation sequencing methods.Keywords: breast cancer, common and rare genetic variation, missing heritability, bioinformatics, exome sequencin

The genetics of breast cancer: risk factors for disease

The genetic factors known to be involved in breast cancer risk comprise about 30 genes. These include the high-penetrance early-onset breast cancer genes, BRCA1 and BRCA2, a number of rare cancer syndrome genes, and rare genes with more moderate penetrance. A larger group of common variants has more recently been identified through genome-wide association studies. Quite a number of these common variants are mapped to genomic regions without being firmly associated with specific genes. It is thought that most of these variants have gene regulatory functions, but their precise roles in disease susceptibility are not well understood. Common variants account for only a small percentage of the risk of disease because they have low penetrance. Collectively, the breast cancer genes identified to date contribute only ~30% of the familial risk. Therefore, there is much interest in accounting for the missing heritability, and possible sources include loss of information through ignoring phenotype heterogeneity (disease subtypes have genetic differences), gene–gene and gene–environment interaction, and rarer forms of variation. Identification of these rarer variations in coding regions is now feasible and cost effective through exome sequencing, which has already identified high-penetrance variants for some rare diseases. Targeting more ‘extreme’ breast cancer phenotypes, particularly cases with early-onset disease, a strong family history (not accounted for by BRCA mutations), and with specific tumor subtypes, provides a route to progress using next-generation sequencing methods