This paper describes in detail the development of a ground-penetrating radar (GPR) model for the acquisition, processing and visualisation of underground utility infrastructure (UUI) in a controlled ...environment. The initiative was to simulate a subsurface urban environment through the construction of regional road, local road and pedestrian pavement in real urban field/testing pools (RUTPs). The RUTPs represented a controlled environment in which the most commonly used utilities were installed. The accuracy of the proposed kinematic GPR-TPS (terrestrial positioning system) model was analysed using all the available data about the materials, whilst taking into account the thickness of the pavement as well as the materials, dimensions and 3D position of the UUI as given reference values. To determine the reference 3D position of the UUI, a terrestrial geodetic surveying method based on the established positional and height geodetic network was used. In the first phase of the model, the geodetic network was used as a starting point for determining the 3D position of the GPR antenna with the efficient kinematic GPR surveying setup using a GPR and self-tracking (robotic) TPS. In the second phase, GPR-TPS system latency was quantified by matching radargram pairs with a set of fidelity measures based on a correlation coefficient and mean squared error. This was followed by the most important phase, where, by combining sets of “standard” processing routines of GPR signals with the support of advanced algorithms for signal processing, UUI were interpreted and visualised semi-automatically. As demonstrated by the results, the proposed GPR model with a kinematic GPR-TPS surveying setup for data acquisition is capable of achieving an accuracy of less than ten centimetres.
Bien que possédant des qualités intrinsèques sans cesse croissantes, notamment leur sensibilité, les tests de dépistage sérologique des marqueurs viraux recherchés sur chaque don de sang ne ...permettent pas dans tous les cas de détecter une infection débutante.
Grâce à la détection supplémentaire des acides nucléiques des virus d'intérêt transfusionnel, 15 à 17 unités potentiellement infectieuses mais séronégatives pourraient être écartées du don chaque année en France et au maximum 10 infections sévères évitées dont 7 liées au seul VHC. Ainsi, le bénéfice le plus important apporté par le dépistage génomique s'applique actuellement au VHC. Ultérieurement, il est possible que cette technologie nouvelle soit élargie aux agents émergents constituant un risque potentiel pour le receveur d'une transfusion. Cependant, même si des kits commercialisés existent, le dépistage génomique comporte des limites méthodologiques et organisationnelles que souligne l'étude de faisabilité du dépistage de l'ARN du VHC sur des pools de dons de sang réalisée sous l'égide de l'Agence française du sang au sein de deux établissements de transfusion sanguine.
Despite sustained improvement of the serologic assays used in blood screening, a small but significant risk remains, due to their failure to identify recently infected donors in the preseroconversion window phase of infection.
If gene amplification assays are added to current screening tests, 15 to 17 additional infectious seronegative blood units could be detected, each year in France and 10 severe diseases avoided, from which 7 are connected to hepatitis C virus. So, the greatest controversy revolve around HCV. In the future, the availability of nucleic acid amplification screening tests, may allow testing of new and emerging agents, of concern. However, even if gene amplification techniques are commercially available, they are not yet suitable for mass screening. Alike other countries in Europe and in USA, a feasability study of the screening of blood donations for HCV-RNA using pooled samples has been undertaken in France.
•Accurate prevalence estimation is crucial for preventing and mitigating emerging and seasonal diseases.•Optimal pooled testing design can lead to efficient prevalence estimation, saving testing ...costs and improving estimation accuracy.•When prior information on the disease of interest is unreliable or unavailable, robust optimal pooled testing designs can significantly improve estimation accuracy, in comparison to deterministic optimal pooled testing designs.
Accurate estimation of disease prevalence is essential for mitigation efforts. Due to limited testing resources, prevalence estimation is often conducted via pooled testing, in which multiple specimens are combined and tested via a single test. The pool design, i.e., the number and sizes of testing pools, has a substantial impact on estimation accuracy. Determining an optimal pool design is challenging, especially for emerging or seasonal diseases for which information on the status of the disease is unreliable or unavailable prior to testing. We develop novel optimization models for testing pool design under uncertainty and limited resources, and characterize structural properties of optimal pool designs. We apply our models to estimate the prevalence of West Nile virus in mosquitoes (the main vector of transmission to humans). Our findings suggest that estimation accuracy can be substantially improved over the status quo through the proposed optimal pool designs.
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