Developing and applying the concept of Value of Information to optimise data collection strategies for seismic hazard assessment

In seismic hazard assessments the importance of knowing different input parameters accurately depends on their weight within the hazard model. Many aspects of such assessments require inputs based on knowledge and data from experts. When it comes to decisions about data collection, facility owners and seismic hazard analysts need to balance the possible added value brought by acquiring new data against the budget and time available for its collection. In other words, they need to answer the question “Is it worth paying to obtain this information?” Assessing the value of information (VoI) before data collection should lead to optimising the time and money that one is willing to invest. This thesis presents a method that combines available data and expert judgment to facilitate the decision-making process within the site-response component of seismic hazard assessments. The approach integrates influence diagrams and decision trees to map the causal-relationships between input parameters in site-response analysis, and Bayesian inference to update the model when new evidence is considered. Here, the VoI is assessed for univariate, bivariate and multivariate uncertain parameters to infer an optimal seismic design for typical buildings and critical facilities. For the first time in the field of seismic hazard assessment and earthquake engineering, a framework is developed to integrate prior knowledge, ground investigation techniques characteristics and design safety requirements. The consistent findings across different applications show that VoI is highly sensitive to prior probabilities and to the accuracy of the test to be performed. This highlights the importance of defining those from available data as well as only considering tests that are suitable for our needs and budget. The developed VoI framework constitutes a useful decision-making tool for hazard analysts and facility owners, enabling not only the prioritisation of data collection for key input parameters and the identification of optimal tests, but also the justification of the associated decisions. This approach can enhance the accuracy and reliability of seismic hazard assessments, leading to more effective risk management strategies.In seismic hazard assessments the importance of knowing different input parameters accurately depends on their weight within the hazard model. Many aspects of such assessments require inputs based on knowledge and data from experts. When it comes to decisions about data collection, facility owners and seismic hazard analysts need to balance the possible added value brought by acquiring new data against the budget and time available for its collection. In other words, they need to answer the question “Is it worth paying to obtain this information?” Assessing the value of information (VoI) before data collection should lead to optimising the time and money that one is willing to invest. This thesis presents a method that combines available data and expert judgment to facilitate the decision-making process within the site-response component of seismic hazard assessments. The approach integrates influence diagrams and decision trees to map the causal-relationships between input parameters in site-response analysis, and Bayesian inference to update the model when new evidence is considered. Here, the VoI is assessed for univariate, bivariate and multivariate uncertain parameters to infer an optimal seismic design for typical buildings and critical facilities. For the first time in the field of seismic hazard assessment and earthquake engineering, a framework is developed to integrate prior knowledge, ground investigation techniques characteristics and design safety requirements. The consistent findings across different applications show that VoI is highly sensitive to prior probabilities and to the accuracy of the test to be performed. This highlights the importance of defining those from available data as well as only considering tests that are suitable for our needs and budget. The developed VoI framework constitutes a useful decision-making tool for hazard analysts and facility owners, enabling not only the prioritisation of data collection for key input parameters and the identification of optimal tests, but also the justification of the associated decisions. This approach can enhance the accuracy and reliability of seismic hazard assessments, leading to more effective risk management strategies

Large Eddy Simulation of a Transonic OutFlow Butterfly Valve

Ce projet de thèse porte sur la compréhension et l'identification des mécanismes de bruit dans les vannes papillons de pressurisation de cabines d'avions à un point de fonctionnement représentatif d'une altitude en vol de 5182 m à l'aide de méthodes numériques. Une première étude numérique consiste à faire des simulations stationnaires de type RANS afin d'avoir une idée préliminaire sur l'écoulement à travers la vanne. Pour les forts ratios de pression simulés, des jets pariétaux supersoniques avec de grandes zones de décollement ont été captés. Pour le ratio de pression d'intérêt de cette thèse, l'écoulement, de nature transsonique, présente des caractéristiques assez complexes avec notamment plusieurs cellules de choc ainsi qu'une zone d'interaction choc/couche limite en début de marche du côté de la lèvre supérieure du papillon. Cette interaction est traduite par deux chocs en lambda successifs. Afin de rendre possible l'étude numérique de ces vannes d'un point de vue acoustique, des simulations instationnaires de type LES à ordre élevé ont pris le relais dans le but de capter le bruit tonal à StD=4.5. En partant du modèle numérique de la vanne proposé par les anciens travaux, plusieurs améliorations topologiques ont été introduites avec notamment l'ajout du réservoir et le raffinement du maillage permettant la propagation acoustique au delà du nombre de Strouhal d'intérêt de 4.5. Une boucle de rétroaction mettant en oeuvre le choc en lambda, la couche de cisaillement et le train de choc a été identifiée. Des ondes de pression fuient de façon périodique la couche de cisaillement à la position de la zone d'interaction choc/couche limite et remontent en amont pour se mélanger à nouveau dans l'écoulement à la position du train de chocs excitant la couche de mélange qui se déstabilise par l'instabilité de Kelvin-Helmholtz. Le calcul acoustique en champ lointain est quant à lui effectué à l'aide de l'analogie de Ffowcs Williams et Hawkings (FW-H). Cependant, la tranche d'épaisseur simulée n'était pas suffisante pour mettre en avant les effets 3D et un blocage en terme de remontée d'information en amont a été recensé à l'aide d'une analyse de cohérence temporelle. Ceci a donc motivé la dernière étape de cette thèse qui consiste à simuler une épaisseur plus réaliste du domaine. Cette dernière configuration a mis en avant les différentes phases de la couche de mélange selon l'envergure ainsi que le comportement non uniforme du deuxième choc en lambda. D'autre part, l'importance des effets 3D sur l'amplification du bruit tonal a été ressentie sur les spectres de bruit en champ lointain avec l'apparition du pic tonal à StD=4.5 et des niveaux à large bande plus élevés. L'analyse modale basée sur la décomposition spectrale en modes propres orthogonaux (SPOD) est venue confirmer ce dernier constat.This thesis deals with the understanding and identification of noise mechanisms in outflow butterfly valves at a representative operating point of a flight altitude of 5182 m using numerical methods. A first numerical study consists in doing stationary RANS type simulations in order to have a preliminary idea on the flow through the valve. For the high simulated pressure ratios, unstable supersonic wall-jets with large separation zones were captured. For the interest pressure ratio, the transonic flow has fairly complex characteristics with in particular several shock cells as well as a zone of shock/boundary layer interaction at the upstream part of the sealing step on the upper lip side of the butterfly. This interaction is translated by two successive lambda shocks. In order to make possible the numerical study of these valves from an acoustic point of view, unsteady high order LES type simulations took over in order to capture the tonal noise at StD = 4.5. Starting from the numerical model of the valve proposed by previous studies, several topological improvements have been introduced with the addition of the tank and mesh refinement allowing the acoustic propagation beyond the Strouhal number interest of 4.5. A feedback loop implementing the lambda shock, the shear layer and the shocks train has been identified. Pressure waves periodically leak the shear layer at the position of the shock / boundary layer interaction zone and travel upstream to mix again in the flow at the position of the shocks train exciting the mixing layer which become unstable due to the Kelvin-Helmholtz instability. The far-field acoustic calculation is carried out using the Ffowcs Williams and Hawkings (FW-H) analogy. However, the simulated thickness was not sufficient to highlight the 3D effects and a blockage in terms of upstream information feedback was identified using a temporal coherence analysis. Therefore, this motivated the last step of this thesis which consists in simulating a fairly real thickness of the domain. This last configuration highlighted the different phases of the shear layer and the non-uniform behaviour of the second lambda shock. On the other hand, the importance of 3D effects on the amplification of the tonal noise was highlighted in the far field noise spectra with the appearance of the tonal peak at StD = 4.5 alongside with higher overall broadband levels. The modal analysis based on Spectral Proper Orthogonal Decomposition has come to confirm this last observation

La monétique et le e-citoyen en Algérie « durant la période 2005-2013 » : la contrainte culturelle Cas des clients de la banque extérieure d’Algérie et la banque de l'Agriculture et du Développement Rural

Le succès de la monétique  est étroitement lié à sa bonne conception, et l’obtention d'acceptation et de satisfaction par les citoyens, les administrations, les institutions, de sorte qu'il doit être élaboré avec la participation de toutes les variables concernés, et commencer à bâtir un environnement électronique approprié, afin de faire transiter  le citoyen ordinaire vers le  e-citoyen, et d’identifier ses priorités. Nous pouvons donc conclure que les services des banques électroniques est une corrélation d’un ensemble d'exigences sous  forme de chaine, afin d'assurer l'acceptation de ce produit dans la communauté, Ainsi, à travers notre recherche, nous allons essayer de trouver les préoccupations qui ont incité le citoyen Algérien de base à s'éloigner de l'utilisation de ce produit.Mots clé : e-citoyen, la monétique, la culture électronique, l’e-éducationإن نجاح الخدمات البنكية الإلكترونية مرتبط بحسن تصميم خدماتها، وحصولها على القبول والرضا من الموطنين، المؤسسات، والإدارات، وسهولة استخدامها. لهذا يجب تطويرها بمشاركة كافة الفعاليات ذات الصلة، والبدء ببناء بيئة إلكترونية ملائمة لتطويرها، مع العمل على إعداد المواطن الإلكتروني، وتحديد أولوياته، لذا يمكننا أن نستنج أن الخدمات البنكية الإلكتونية هي عبارة عن إرتباط مجموعة  من المتطلبات في شكل سلسلة ، و العلاقة بينهم يجب أن تكون في شكل علاقة مكملة لبعضها البعض، من أجل ضمان قبول هذا المنتج في المجتمع، لذا من خلال بحثنا سنحاول معرفة الأسباب الرئيسية           او المخاوف الأساسية التي دفعت المواطن الجزائري للإبتعاد عن إستخدام هذا المنتجالكلمات المفتاحية: المواطن الإلكتروني ، الخدمات البنكية الإلكترونية، الثقافة الإلكترونية، التربية الإلكتروني

Rheological behavior and microstructural evolution of semi-solid hypereutectic Al-Si-Mg-Cu alloys using rheoforming process

Over the last three decades the semi-solid metal (SSM) processing has received significant attention. Semi-solid processing involves the net shape manufacturing of alloys in the semi-solid state. The principal attraction for the process has been the unique rheology of the slurry which induces better movement of materials through the die and allows intricate thin-wall near net shape components to be cast at lower applied pressures. This behaviour offers considerable advantages to the quality of castings. The reduced oxide entrapment, low porosity and a lower operating temperature make semi-solid processing ideal for the forming of high integrity parts. The aim of the current study was to investigate the rheological behavior and microstructural evolution of hypereutectic Al-Si-Cu and Al-Si-Mg-Cu alloys using conventional and modified SEED process (Swirled Enthalpy Equilibration Device). This project is divided into four parts. In the first part, the feasibility of semi-solid processing of hypereutectic Al-Si-Cu A390 alloys using a novel rheoforming process was investigated. A combination of the SEED process, isothermal holding using insulation and addition of solid alloy during swirling was introduced as a novel method to improve the processability of semi-solid A390 slurries. The effects of isothermal holding and the addition of solid alloy on the temperature gradient between the centre and the wall and on the formation of a-Al particles were examined. In addition, phosphorus and strontium were added to the molten metal to refine the primary and eutectic silicon structure to facilitate semi-solid processing. It was found that the combination of the SEED process with two additional processing steps can produce semisolid 390 alloys that can be rheoformed. The microstructure reveals an adequate amount of non-dendritic a-Al globules surrounded by liquid, which greatly improves the processability of semi-solid A390 slurries. In the second part, the effects of Mg additions ranging from 6 to 15% on the solidification behaviour of hypereutectic Al-15Si-xMg-4Cu alloys was investigated using thermodynamic calculations, thermal analysis and extensive microstructural examination. The Mg level strongly influenced the microstructural evolution of the primary Mg2Si phase as well as the solidification behaviour. Thermodynamic predictions using ThermoCalc software reported the occurrence of six reactions, comprising the formation of primary Mg2Si, two pre-eutectic binary reactions, forming either Mg2Si + Si or Mg2Si + a-Al phases, the main ternary eutectic reaction forming Mg2Si + Si + a-Al, and two post-eutectic reactions resulting in the precipitation of the Q-Al5Mg8Cu2Si6 and O-Al2Cu phases, respectively. Microstructures of the four alloys studied confirmed the presence of these phases, in addition to that of the 7i-AlgMg3FeSi6 phase. The presence of the pi-phase was also confirmed by thermal analysis. The morphology of the primary Mg2Si phase changed from an octahedral to a dendrite form at 12.52% Mg. Further Mg addition only coarsened the dendrites. Image analysis measurements revealed a close correlation between measured and calculated phase fractions of the primary Mg2Si and Si phases. ThermoCalc and Scheil calculations show good agreement with the experimental results obtained from microstructural and thermal analyses. In the third part, the effects of P and Sr on the microstructure of hypereutectic Al-15Si-14Mg-4Cu alloy were studied. The microstructural examination and phase identification were carried out using optical microscopy and scanning electron microscopy (SEM). The effects of individual and combined additions of P and Sr on the eutectic arrest in Al-15Si-14Mg-4Cu alloy were examined using thermal analysis. The mean size of primary Mg2Si decreases from about 350 um to less than 60 um and the morphology changes from coarse dendritic type or equiaxed to polygonal type. In addition, the morphology of the eutectic Mg2Si phase changes from coarse Chinese script to fine fiber-like, while that of the eutectic Si phase changes from coarse acicular shape to a fine fibrous form. With Sr addition, the morphology of the pi-Fe phase evolved from Chinese script to a fine twin platelet form. Furthermore, the thermal analysis results reveal that the addition of Sr or Sr and P reduces the temperature of eutectic nucleation and growth. Quantitative measurements revealed a reduction in the particle area and an increase of the density of Mg2Si, Si and pi-Fe phases. The Sr or Sr + P combined additions are effective in modifying the eutectic Si, Mg2Si and pi-Fe phases for the Al-15 Si-14Mg-4Cu alloy. Finally, the rheological behaviour and microstructure of semi-solid hypereutectic A390, P-refined A390, Al-15Si-10.5Mg-4Cu and Al-15Si-13.5Mg-4Cu alloys were investigated by using parallel plate viscometry. The flow deformation of these alloys in the semi-solid state was characterized at different deformation rates and at variable solid fractions. The calculated viscosity for variable shear rate was deduced using the analytical method developed by Laxmanan and Flemings. Microstructures of the four alloys, after partial solidification, were examined in order to characterize the flow behaviour during deformation. An image analysis was used for quantification of particle segregation and effective volume fraction. The apparent viscosity of all studied alloys increased with increasing solid volume fraction, and decreased with increasing shear rate. The comparison of the apparent viscosity of the four alloys indicated that the higher the Mg in the alloy, the higher the apparent viscosity was for the range of shear rates and solid fractions investigated. It is also shown that the refined A390 alloy has the lowest apparent viscosity due to the small size of primary Si particles. In addition, a separation of liquid and solid phase was also observed for all alloys in the microstructure study of deformed semi-solid billets. - Au cours des trois derrières décennies, la mise en forme à l'état semi-solide a suscité beaucoup d'attention. Cette méthode consiste à fabriquer des pièces mécaniques finies à l'état semi solide. L'attraction principale de cette technique réside essentiellement dans son unique propriété rhéologique qui confère un meilleur écoulement à la gelée à travers la filière du moule et permet par la suite l'optimisation de la pression nécessaire pour un remplissage adéquat. L'objectif principal de ce travail est l'élude du comportement rhéologique ainsi que l'évolution microstructurale des alliages hypereutectiques Al-Si-Mg-Cu en utilisant deux méthodes différentes, le procédé SEED conventionnel et modifié. Ce travail de recherche est divisé en quatre parties. La première partie est consacrée à l'étude de la faisabilité de la mise en forme à l'état semi-solide d'alliage hypereutectique Al-Si-Cu 390 en utilisant un nouveau procédé de rhéoformage. En effet, la combinaison du procédé SEED conventionnel, un maintien isotherme avec isolation du moule et l'ajout de petits morceaux d'alliages pendant le brassage a été introduit comme une nouvelle méthode capable de produire une gelée. Par la suite, l'effet induit par le maintien isotherme et l'ajout de morceaux d'alliages sur le gradient de température au centre et à la paroi du moule ainsi que sur la formation des particules a-Al a été examiné. Dans certain tests supplémentaires, des quantités appropriées de phosphore et de strontium ont été introduite dans le métal liquide dans le but d'affiner le silicium primaire et eutectique, et faciliter par la suite la mise en forme de la gelée. Il a été constaté que la combinaison du procédé SEED avec deux étapes supplémentaires est une technique capable de produire une gelée d'alliage A390. En plus, la microstructure de la gelée révèle une quantité suffisante de globules d'aluminium (a-Al) entourées de liquide. Dans la deuxième partie, l'effet de l'addition de quantités de Mg allant de 6 à 15% sur le chemin de solidification et la microstructure des alliages hypereutectiques Al-15Si-xMg-4Cu a été étudié en utilisant des calculs thermodynamiques, une analyse thermique et un examen microstructural approfondi. La teneur en Mg influence fortement la cinétique de formation de la phase primaire Mg2Si ainsi que le chemin de solidification du système. La prédiction thermodynamique en utilisant ThermoCalc montre l'existence de six réactions, incluant la formation de la phase primaire Mg2Si, deux réactions pré-eutectique binaires formant soit les phases Mg2Si et Si ou Mg2Si et a-Al, la réaction eutectique ternaire (Mg2Si + Si + a-Al), et deux réactions post-eutectiques aboutissant à la précipitation des phases QAl5Mg8Cu2Si6 et O-Al2Cu, respectivement. Les microstructures des quatre alliages étudiés ont par la suite confirmé la présence de toutes ces phases, y compris la phase nIV Al8Mg3FeSi6. La présence de la phase pi-Fe riche en fer a été également confirmée par l'analyse thermique. L'addition de teneurs supérieures à 12.52% Mg induit une évolution de la morphologie de la phase primaire Mg2Si d'une forme octaédrique vers une forme dendritique et une augmentation significative des dendrites. L'analyse quantitative a révélé une corrélation entre les fractions volumiques mesurées et calculées de la phase primaire Mg2Si et Si. Enfin, les résultats obtenues par ThermoCalc et soutenues par la méthode Scheil montrent un bon accord avec les résultats expérimentaux obtenus à partir des analyses microstructuraux et thermiques. Dans la troisième partie, l'effet des éléments d'addition P et Sr sur la microstructure de l'alliage hypereutectique Al-15Si-14Mg-4Cu a été étudié. La caractérisation microstructural et l'identification des différentes phases ont été réalisées en utilisant un microscope optique et un microscope électronique à balayage (MEB). L'apport individuel et combiné de P et Sr sur la température eutectique de l'alliage Al-15Si-14Mg-4Cu a été étudié à l'aide de l'analyse thermique. La taille moyenne de la phase primaire Mg2Si a diminuée de 350 um à moins de 60 um et sa morphologie a évoluée d'une forme dendritique vers une forme polygonale. En plus, la morphologie des phases eutectique Mg2Si et Si ont changé respectivement d'une forme d'écriture chinoise et d'une forme aciculaire vers une forme fibreuse de taille fine. L'addition de Sr a aussi montré le changement de la morphologie de la phase intermétallique 7t-Fe. Les résultats de l'analyse thermique ont révélés une diminution des températures de germination et de croissance eutectique. L'analyse quantitative a montrée une réduction de la taille des particules et l'augmentation de la densité des phases Mg2Si, Si et rc-Fe. L'addition de Sr ou la combinaison de Sr avec P est avéré très efficace pour affiner la phase primaire Mg2Si et modifier les phases eutectiques Mg2Si, Si ainsi que la phase rc-Fe de l'alliage Al-15Si-14Mg-4Cu. Enfin, le comportement rhéologique et l'évolution microstructural des alliages hypereutectique A390, A390 affiné, Al-15Si-10.5Mg-4Cu et Al-15Si-13.5Mg-4Cu à l'état semi-solide ont été étudiés à l'aide d'un viscosimètre. La déformation de ces quatre alliages à l'état semi-solide a été caractérisée à différentes vitesses de déformations et à fractions de solides variables. La viscosité apparente a été calculée en utilisant le modèle développé par Laxmanan et Flemings. Les microstructures des quatre alliages, après solidification partielle, ont été examinées afin de caractériser le comportement rhéologique lors de la déformation. Une analyse d'image a été réalisée pour quantifier la ségrégation des particules solides et la fraction volumique effective. Les résultats montrent une augmentation de la viscosité apparente des quatre alliages étudiés avec l'augmentation de la fraction solide, et la diminution du taux de cisaillement. La comparaison de la viscosité apparente des quatre alliages indiquait que l'alliage contenant une teneur élevée en Mg possédait une plus grande viscosité apparente pour la gamme du taux de cisaillement et de fractions solides étudiés. Il est également montré que l'alliage affiné A390 a la plus faible viscosité apparente en raison de la diminution de la taille des particules de silicium primaire. En outre, une séparation des phases liquides et solides a également été observée pour tous les alliages au cours de l'étude microstructural des billettes déformées à l'état semi-solide

Prevalence and risk factors of Strongyloides stercoralis in haemodialysis in Cochabamba, Bolivia: a cross-sectional study.

BACKGROUND Strongyloidiasis is an infectious disease that can be fatal in immunocompromised patients. Patients with end-stage renal failure who are on dialysis have a considerably weakened immune system, and organ transplantation is a major risk factor for severe strongyloidiasis. Knowledge of the local epidemiology in tropical and subtropical areas is an essential prerequisite for designing an appropriate strategy to prevent this potentially lethal complication. In this study, we aimed to estimate the prevalence and associated risk factors of S. stercoralis infection in patients on dialysis in Cochabamba, Bolivia. METHODS A cross-sectional study was carried out among patients undergoing haemodialysis in Cochabamba (elevation 2,500 m, temperate climate), collecting information on socio-demographic, lifestyle, and clinical variables, and using one coproparasitological technique (the modified Baermann technique) and one serological (ELISA) test for S.stercoralis diagnosis. RESULTS In total, 149 patients participated in the study (mean age = 51.4 years, 48.3% male). End-stage renal disease was predominantly (59%) of hypertensive and/or diabetic origin. The positive serological prevalence was 18.8% (95% CI: 13.3%-25.9%). Based on the sensitivity and specificity of the ELISA test, the estimate of the actual prevalence was 15.1% (95% CI: 9.4%-20.7%). Stool samples of 105 patients (70.5%) showed a coproparasitological prevalence of 1.9% (95% CI: 0.52%-6.68%). No potential risk factors were significantly associated with S. stercoralis infection. CONCLUSIONS We found a high seroprevalence of S. stercoralis in Bolivian patients undergoing haemodialysis in Cochabamba. We recommend presumptive antiparasitic treatment at regular intervals to avoid the potentially fatal complications of severe strongyloidiasis

Infliximab therapy in rheumatoid arthritis and ankylosing spondylitis-induced specific antinuclear and antiphospholipid autoantibodies without autoimmune clinical manifestations: a two-year prospective study

Treatment of rheumatoid arthritis (RA) with infliximab (Remicade(®)) has been associated with the induction of antinuclear autoantibodies (ANA) and anti-double-stranded DNA (anti-dsDNA) autoantibodies. In the present study we investigated the humoral immune response induced by infliximab against organ-specific or non-organ-specific antigens not only in RA patients but also in patients with ankylosing spondylitis (AS) during a two-year followup. The association between the presence of autoantibodies and clinical manifestations was then examined. The occurrence of the various autoantibodies was analyzed in 24 RA and 15 AS patients all treated with infliximab and in 30 RA patients receiving methotrexate but not infliximab, using the appropriate methods of detection. Infliximab led to a significant induction of ANA and anti-dsDNA autoantibodies in 86.7% and 57% of RA patients and in 85% and 31% of AS patients, respectively. The incidence of antiphospholipid (aPL) autoantibodies was significantly higher in both RA patients (21%) and AS patients (27%) than in the control group. Most anti-dsDNA and aPL autoantibodies were of IgM isotype and were not associated with infusion side effects, lupus-like manifestations or infectious disease. No other autoantibodies were shown to be induced by the treatment. Our results confirmed the occurrence of ANA and anti-dsDNA autoantibodies and demonstrated that the induction of ANA, anti-dsDNA and aPL autoantibodies is related to infliximab treatment in both RA and AS, with no significant relationship to clinical manifestations

Assessing the value of information in site-response analysis

In seismic hazard assessments the importance of knowing different input parameters accurately depends on their weights within the hazard model. Many aspects of such assessments require inputs based on knowledge and data from experts. When it comes to decisions about data collection, facility owners and seismic hazard analysts need to estimate the possible added value brought by acquiring new data along with the budget and time available for its collection. In other words, they need to answer the question "Is it worth paying to obtain this information?". Assessing the value of information (VoI) before data collection should lead to optimising the time and money that one is willing to invest. In this article, we propose a method that combines available data and expert elicitation to facilitate the decision-making process within the site-response component of seismic hazard assessment. The approach combines Bayesian networks and decision trees to translate the causal-relationships between the input parameters in site-response analysis and Bayesian inference to update the model when new evidence is considered. Here, we assess VoI for a hypothetical site. Our analysis shows that VoI is highly sensitive to prior probabilities and the accuracy of the test to be performed. This highlights the importance of defining those from available information as well as considering only tests that are suitable for our needs and budget

Using the Value of Information to decide when to collect additional data on near-surface site conditions

When funding or conducting a seismic hazard assessment, facility owners and seismic hazard analysts need to estimate the possible added value that could be obtained by collecting additional data to inform the assessment. This added value needs to be balanced against the budget and time available for the collection of the data. In other words, they need to answer the question "Is it worth paying to obtain this information?". Conducting a Value of Information (VoI) analysis before any data collection would help to answer this question and to optimise the data collection process. In this article, we develop and illustrate a method to assess the VoI of improving estimates of the average shear-wave velocity in the top 30m within the site-response component of a seismic hazard assessment to decide on the optimal seismic design for a reference building in Greece. The approach is based on decision trees to translate the causal relationships between the input parameters in site-response analysis and Bayesian inference to update the model when new data are considered. The results show that VoI is highly sensitive to prior probabilities and the accuracy of the data collection method (e.g. geophysical survey). This stresses the importance of defining prior probabilities based on available information as well as only considering data collection methods that are suitable for a project’s needs and budget

A severe clinical phenotype of Noonan syndrome with neonatal hypertrophic cardiomyopathy in the second case worldwide with RAF1 S259Y neomutation

International audienceNoonan syndrome and related disorders are a group of clinically and genetically heterogeneous conditions caused by mutations in genes of the RAS/MAPK pathway. Noonan syndrome causes multiple congenital anomalies, which are frequently accompanied by hypertrophic cardiomyopathy (HCM). We report here a Tunisian patient with a severe phenotype of Noonan syndrome including neonatal HCM, facial dysmorphism, severe failure to thrive, cutaneous abnormalities, pectus excavatum and severe stunted growth, who died in her eighth month of life. Using whole exome sequencing, we identified a de novo mutation in exon 7 of the RAF1 gene: c.776C > A (p.Ser259Tyr). This mutation affects a highly conserved serine residue, a main mediator of Raf-1 inhibition via phosphorylation. To our knowledge the c.776C > A mutation has been previously reported in only one case with prenatally diagnosed Noonan syndrome. Our study further supports the striking correlation of RAF1 mutations with HCM and highlights the clinical severity of Noonan syndrome associated with a RAF1 p.Ser259Tyr mutation