De l'équation mathématique au programme informatique, dialogue entre mathématiciens et informaticiens

L'essor de l'informatique réactive les débats sur la nature des activités de modélisation et de simulation. Ce forum réunit des mathématiciens et des informaticiens à propos de la place respective des mathématiques et de l'informatique dans les modèles. La première partie propose deux exemples d'implication des mathématiques dans les sciences de la vie, et traite ensuite de la distinction entre deux formes de modélisation d'une même réalité, par une mise en équation ou une mise en programme, en soulignant la nécessité de théoriser les modèles informatiques. La seconde partie présente les apports complémentaires, à trois niveaux, des mathématiques et de l'informatique dans le cas des modèles à base d'agents. Le débat à plusieurs voix revient ensuite sur le choix du type de modélisation face au problème posé, les différences entre équations et programmes, les vérités issues des théorèmes ou des simulations, le rôle de l'expérimentation

Legends of the Ardennes Massif, a cross-border intangible geo-cultural heritage (Belgium, Luxemburg, France, Germany)

Myths and legends related to geological phenomena or stunning landscapes are common in the cross-border Ardennes Massif. They represent an important intangible geo-cultural heritage. Those legends add an extra dimension to the holistic experience of geoheritage in the western part of the Variscan Rhenish massif, which is also world famous for its International Union of Geological Sciences-acknowledged stratigraphical reference sections of the Palaeozoic era. Of particular interest are the many legends devoted to the devil, aiming to explain occurrences of "unusual" forms, sizes or numbers of rocks, boulders or particular rock formations in the landscape. The Ardennes is also known for its legends about emblematic historical characters, such as Emperor Charlemagne and Saint Remacle, commonly used to elucidate the strange or suspect occurrences of the above geological items. The medieval legends of the Four Sons of Aymon and that of their magical bay horse Bayard are strongly rooted in the Ardennes tradition and the local geology: many outstanding rock formations or geomorphological features have been named after these characters. Moreover, both gave their name to official geological formations. Other legends, such as the one dealing with the Giant's Tomb or those related to the activities of dwarf-like creatures, fairies and witches, rather represent folktales involving direct or indirect links with geological curiosities (particular rock formations, caves, springs, etc.). A real cross-border network of geotouristic legend roads could certainly enhance public awareness and stimulate decision-makers to valorize the great potential of this less-known intangible geological-cultural heritage

Use of real-world evidence in meta-analyses and cost-effectiveness models

Real-world evidence (RWE) provides external validity, supplementing and enhancing the randomized controlled trial data with valuable information on patient behaviors and outcomes, turning efficacy and safety results into real-world effectiveness and risks, but the use of RWE is associated with challenges. The objectives of this communication were to (1) summarize all guidance on how to conduct an RWE meta-analysis (MA) and how to develop an RWE cost-effectiveness model, (2) to describe our experience, challenges faced and solutions identified, (3) to provide recommendations on how to conduct such analyses. No formal guidelines on how to conduct an RWE MA or to develop an RWE cost-effectiveness model were identified. Using the context of non-vitamin K antagonist oral anticoagulants in stroke prevention in atrial fibrillation, we conducted an RWE MA, after having identified sources of uncertainty. We then implemented the results in an RWE cost-effectiveness model, defined as a model where all inputs come from RWE, including all parameters related to treatment effect. Based on challenges faced, our first recommendation relates to the necessity of conducting sensitivity analyses, either based on clinical or methodological considerations. Our second recommendation is the need for extensive collaboration with a wide range of experts, during the development of the analyses protocols, the implementation of the analyses and the interpretation of the results. RWE may address a number of gaps related to the treatment effect, and RWE economic evaluations for the treatment effect can provide extremely valuable insights into real-world economic value of interventions. As the increased recognition of the value of RWE could influence health technology assessment decision, and current practices, this communication supports the urgent need of more formal guidelines

Integrated waveguide interferometer with picometric performances

International audienceWe present an integrated optical waveguide interferometer highly compact and easy-to-use. Metrological study is focused on the resolution and the noise level of the sensor. A standard Allan deviation lower than 50 pm has been observed in standard environment. Power spectral densities up to 150 fm.Hz-1/2 at 10 kHz are achieved. The flicker level is not reached because of the environmental conditions but the high frequency noise is likely to be lower than 100 fm. Hz-1/2. We present measures for steps of 0.5 nm at a sample frequency of 1 kHz. Although we use it as sensing motions measurement over micrometric range, the maximum displacement range is 5 centimeters depending on the output lens which is used

Real-world cost-effectiveness of rivaroxaban and apixaban vs VKA in stroke prevention in non-valvular atrial fibrillation in the UK

International audienceBackground: Morbidity and mortality associated with non-valvular atrial fibrillation (NVAF) imposes a substantial economic burden on the UK healthcare system. Objectives: An existing Markov model was adapted to assess the real-world cost-effectiveness of rivaroxaban and apixaban, each compared with a vitamin K antagonist (VKA), for stroke prevention in patients with NVAF from the National Health Service (NHS) and personal and social services (PSS) perspective. Methods: The model considered a cycle length of 3 months over a lifetime horizon. All inputs were drawn from real-world evidence (RWE): baseline patient characteristics, clinical event and persistence rates, treatment effect (meta-analysis of RWE studies), utility values and resource use. Deterministic and probabilistic sensitivity analyses were performed. Results: The incremental cost per quality-adjusted life year was £14,437 for rivaroxaban, and £20,101 for apixaban, compared with VKA. The probabilities to be cost-effective compared with VKA were 90% and 81%, respectively for rivaroxaban and apixaban, considering a £20,000 threshold. In both comparisons, the results were most sensitive to clinical event rates. Conclusions: These results suggest that rivaroxaban and apixaban are cost-effective vs VKA, based on RWE, considering a £20,000 threshold, from the NHS and PSS perspective in the UK for stroke prevention in patients with NVAF. This economic evaluation may provide valuable information for decision-makers, in a context where RWE is more accessible and its value more acknowledged

Health related quality of life in patients having schizophrenia negative symptoms – a systematic review

Background: Schizophrenia negative symptoms (SNS) contribute substantially to poor functional outcomes, loss in productivity and poor quality of life. It is unclear which instruments may be used for assessing quality of life in patients with SNS. Objective: The objective of this review was to identify instruments assessing health-related quality of life (HRQoL) validated in patients with SNS and to assess their level of validation. Data sources: We conducted a systematic literature review in Medline and the ISPOR database in March 2016 to identify studies on the quality of life in patients with SNS published by March 2016. Data extraction: Psychometric properties and validation steps. Data synthesis: After applying inclusion/exclusion criteria, 49 studies were selected for the analysis of HRQoL instruments; however, none of these instruments only addressed patients with SNS. Of these, 19 HRQoL instruments used in patients with schizophrenia or including patients with SNS among others, in the context of instrument validation, were identified (4 generic, 10 non-specific mental health, 5 schizophrenia-specific). Conclusion: No HRQoL instrument has been validated in patients with SNS only; for the remaining instruments identified, it remains unclear whether they were intended to capture HRQoL in patients with SNS

Real-world cost-effectiveness of rivaroxaban compared with vitamin K antagonists in the context of stroke prevention in atrial fibrillation in France

International audienc