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Anticipating the demographic future requires questioning the methods, hypotheses, laws, regularities, terminologies, and implications that accompany and enable conjecture. This presentation sets out some theoretical and historical benchmarks relating to the specific practice of demographers in anticipating future demographic developments. It discusses the main areas where demographic forecasts, prospects and projections are useful and highlights the pitfalls to be avoided., Anticiper l’avenir démographique nécessite de s’interroger sur les méthodes, les hypothèses, les lois, les régularités, les terminologies, les implications qui accompagnent et permettent la conjecture. Cette présentation pose quelques repères théoriques et historiques relatifs à la pratique spécifique des démographes pour anticiper les évolutions démographiques futures. Elle aborde les principaux domaines où les prévisions, perspectives et projections démographiques sont utiles et souligne les écueils à éviter.

International audience; Kelp forests, primarily Laminaria digitata, provide a broad range of ecosystem services of high social, economic, and ecological value and are considered one of the most productive ecosystems on the planet. Several studies have shown that kelp ecosystems are regressing in response to multiple stressors, especially climate change, which could lead to local extinctions. This may induce a decrease in the ecosystem services provided. Many studies use ecological niche models (ENM) to project potential future species distributions under climate change scenarios; however, no study has projected the future supply of ecosystem services resulting from shifts in species ranges and changes in biomass. In this study, using French coasts as a case study, we developed a new and reproducible methodological framework that combines ENM and ecosystem services indicators to assess impacts of climate change on ecosystem services supplied by kelp. To this end, we first identified ecosystem services currently provided by kelp and then used ENM to project future kelp distribution from 2041 to 2050 under climate scenarios RCP2.6 and RCP8.5. Finally, by estimating the biomass of kelp, we assessed the current and future ecosystem services provided by kelp.

International audience; Proper maternal care is an essential factor of reproductive success in mammals, involving a repertoire of behaviors oriented toward the feeding and care of the offspring. Among the neurotransmitters involved in the initiation of these behaviors, serotonin (5-HT) seems to play an important role. Here we compared pup-oriented maternal behaviors in mice with constitutive 5-HT depletion, the tryptophan hydroxylase 2-knock-out (Tph2-KO) and the Pet1-KO mice. We report that the only common pup-oriented defect in these 2 hyposerotoninergic models is a defective nursing in parturient mice and altered nursing-like (crouching) behavior in virgin mice, while pup retrieval defects are only present in Tph2-KO. Despite a normal mammary gland development and milk production, the defect in appropriate nursing is responsible for severe growth retardation and early lethality of pups born to hyposerotonergic dams. This nursing defect is due to acute rather constitutive 5-HT depletion, as it is reproduced by adult knockdown of Tph2 in the dorsal raphe nucleus in mothers with a prior normal maternal experience. We conclude that 5-HT innervation from the dorsal raphe is required for both the initiation and maintenance of a normal nursing behavior. Our findings may be related to observations of reduced maternal/infant interactions in human depression.

Sea-level rise (SLR) will be one of the major climate change-induced risks of the 21st century for coastal areas. The large uncertainties of ice sheet melting processes bring in a range of unlikely – but not impossible – high-end sea-level scenarios (HESs). Here, we provide global to regional HESs exploring the tails of the distribution estimates of the different components of sea level. We base our scenarios on high-end physical-based model projections for glaciers, ocean sterodynamic effects, glacial isostatic adjustment and contributions from land-water, and we rely on a recent expert elicitation assessment for Greenland and Antarctic ice-sheets. We consider two future emissions scenarios and three time horizons that are critical for risk-averse stakeholders (2050, 2100, and 2200). We present our results from global to regional scales and highlight HESs spatial divergence and their departure from global HESs through twelve coastal city and island examples. For HESs-A, the global mean-sea level (GMSL) is projected to reach 1.06(1.91) in the low(high) emission scenario by 2100. For HESs-B, GMSL may be higher than 1.69(3.22) m by 2100. As far as 2050, while in most regions SLR may be of the same order of magnitude as GMSL, at local scale where ice-sheets existed during the Last Glacial Maximum, SLR can be far lower than GMSL, as in the Gulf of Finland. Beyond 2050, as sea-level continue to rise under the HESs, in most regions increasing rates of minimum(maximum) HESs are projected at high(low-to-mid) latitudes, close to (far from) ice-sheets, resulting in regional HESs substantially lower(higher) than GMSL. In regions where HESs may be extremely high, some cities in South East Asia such as Manila are even more immediately affected by coastal subsidence, which causes relative sea-level changes that exceed our HESs by one order of magnitude in some sectors.

International audience; A high-resolution climate projections dataset is obtained by statistically downscaling climate projections from the CMIP5 experiment using the ERA5 reanalysis from the Copernicus Climate Change Service. This global dataset has a spatial resolution of 0.25°x 0.25°, comprises 21 climate models and includes 5 surface daily variables at monthly resolution: air temperature (mean, minimum, and maximum), precipitation, and mean near-surface wind speed. Two greenhouse gas emissions scenarios are available: one with mitigation policy (RCP4.5) and one without mitigation (RCP8.5). The downscaling method is a Quantile Mapping method (QM) called the Cumulative Distribution Function transform (CDF-t) method that was first used for wind values and is now referenced in dozens of peer-reviewed publications. The data processing includes quality control of metadata according to the climate modeling community standards and value checking for outlier detection.

International audience; The aim of this paper is to study $L^p$-projections, a notion introduced by Cunningham in 1953, on subspaces and quotients of complex Banach spaces. An $L^p$-projection on a Banach space $X$, for $1\leq p \leq +\infty$, is an idempotent operator $P$ satisfying $ \|f\|_X = \|( \|P(f)\|_X, \|(I-P)(f)\|_X) \|_{\ell_{p}}$ for all $f \in X$. This is an $L^p$ version of the equality $\|f\|^2=\|Q(f)\|^2 + \|(I-Q)(f)\|^2$, valid for orthogonal projections on Hilbert spaces. We study the relationships between $L^p$-projections on a Banach space $X$ and those on a subspace $F$, as well as relationships between $L^p$-projections on $X$ and those on the quotient space $X/F$.All the results in this paper are true for $1

WOS:000684889700001; Climate change is rapidly becoming one of the biggest threats to marine life, and its impacts have the potential to strongly affect fisheries upon which millions of people rely. This is particularly crucial for the Mediterranean Sea, which is one of the world's biodiversity hotspots, one of the world's most overfished regions, and where temperatures are rising 25% faster than in the rest of the ocean on average. In this study, we calculated a vulnerability index for 100 species that compose 95% of the Mediterranean catches, through a trait-based approach. The Climate Risk Assessment (CRA) methodology was subsequently used to assess the risks due to climate change of Mediterranean fisheries. We found that the northern Mediterranean fisheries target more vulnerable species than their southern counterparts. However, when combining this catch-based vulnerability with a suite of socio-economic parameters, north African countries stand out as the most vulnerable to climate change impacts. Indeed, considering countries' exposure of the fisheries sector and their vulnerability to climate change, a sharp contrast between northern and southern Mediterranean appears, with Egypt and Tunisia scoring the highest risk. By integrating a trait-based approach on targeted marine species with socio-economic features, our analysis helps to better understand the ramifications of climate change consequences on Mediterranean fisheries and highlights the regions that could potentially be particularly affected.

Made available in DSpace on 2022-04-29T08:31:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Global warming is likely to cause a progressive drought increase in some regions, but how population and natural resources will be affected is still underexplored. This study focuses on global population and land-use (forests, croplands, pastures) exposure to meteorological drought hazard in the 21st century, expressed as frequency and severity of drought events. As input, we use a large ensemble of climate simulations from the Coordinated Regional Climate Downscaling Experiment, population projections from the NASA-SEDAC dataset, and land-use projections from the Land-Use Harmonization 2 project for 1981–2100. The exposure to drought hazard is presented for five SSPs (SSP1-SSP5) at four Global Warming Levels (GWLs, from 1.5 to 4°C). Results show that considering only Standardized Precipitation Index (SPI; based on precipitation), the combination SSP3-GWL4 projects the largest fraction of the global population (14%) to experience an increase in drought frequency and severity (vs. 1981–2010), with this value increasing to 60% if temperature is considered (indirectly included in the Standardized Precipitation-Evapotranspiration Index, SPEI). With SPEI, considering the highest GWL for each SSP, 8 (for SSP2, SSP4, and SSP5) and 11 (SSP3) billion people, that is, more than 90%, will be affected by at least one unprecedented drought. For SSP5 (fossil-fuelled development) at GWL 4°C, approximately 2·106 km2 of forests and croplands (respectively, 6 and 11%) and 1.5·106 km2 of pastures (19%) will be exposed to increased drought frequency and severity according to SPI, but for SPEI, this extent will rise to 17·106 km2 of forests (49%), 6·106 km2 of pastures (78%), and 12·106 km2 of croplands (67%), with mid-latitudes being the most affected areas. The projected likely increase of drought frequency and severity significantly increases population and land-use exposure to drought, even at low GWLs, thus extensive mitigation and adaptation efforts are needed to avoid the most severe impacts of climate change. European Commission Joint Research Centre (JRC) Centro Euro-Mediterraneo sui Cambiamenti Climatici (CMCC Foundation—REMHI Division) Cooperative Institute for Research in Environmental Sciences (CIRES) and Department of Atmospheric and Oceanic Sciences Snow and Ice Data Center University of Colorado Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) University of Copenhagen Niels Bohr Institute (NBI) Danish Meteorological Institute Abdus Salam International Centre for Theoretical Physics (ICTP) Faculty of Science University of New South Wales Helmholtz-Zentrum Geesthacht (HZG) Institute of Coastal Research The Cyprus Institute (CyI) Climate and Atmosphere Research Center (CARE-C) Climate Service Center Germany (GERICS) Helmholtz-Zentrum Geesthacht Commonwealth Scientific and Industrial Research Organisation (CSIRO) Marine and Atmospheric Research Swedish Meteorological and Hydrological Institute (SMHI) Rossby Centre Département des Sciences de la Terre et de l'Atmosphère Université du Quebec à Montréal (UQAM) University of Cape Town Climate System Analysis Group (CSAG) Department of Physics Faculty of Arts and Sciences Bogazici University Center for Climate Change and Policy Studies Bogazici University Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences (CAS) São Paulo State University and Bauru Meteorological Centre (IPMet/UNESP) Department of Physics Faculty of Arts and Sciences Isik University Institute of Meteorology and Climate Research Karlsruhe Institute of Technology (KIT) Departamento de Ciências Atmosféricas Universidade de São Paulo Facultad de Ciencias Exactas y Naturales Departamento de Ciencias de la Atmósfera y los Océanos (DCAO-FCEN-UBA) Universidad de Buenos Aires Universidad de Buenos Aires Centro de Investigaciones del Mar y la Atmósfera (CIMA/CONICET-UBA) School of Biological Sciences The University of Queensland Department of Earth Sciences and Environment The National University of Malaysia (UKM) National Centre for Scientific Research (CNRS) Institut Pierre-Simon Laplace (IPSL) Laboratoire des Sciences du Climat et de l'Environnement (LSCE) NORCE Norwegian Research Centre AS Centro Italiano Ricerche Aerospaziali (CIRA) São Paulo State University and Bauru Meteorological Centre (IPMet/UNESP)

Wildfire is the main disturbance in forested ecosystems of southern Europe and is due to complex interactions between climate-weather, fuels and people. Warmer and drier conditions projected in this region are expected to profoundly affect wildfires, which will impact ecosystems and humans. We review the scientific literature addressing the assessment of climate change impacts on wildfires in southern Europe, with a twofold objective: (i) report the trends in wildfire danger and activity projected under warming climate in southern Europe and (ii) discuss the limitations of wildfire projections under the specific biogeographical context of southern Europe.We identified 22 projection studies that examined future wildfire danger or wildfire activity at local, regional or continental scale. Under the scenario with the highest greenhouse gas emissions, we found that projections studies estimate an increase in future fire danger and burnt areas varying, on average, from 2 to 4 % and from 15 to 25 % per decade, respectively. Fire-prone area expansion to the north and to Mediterranean mountains is a concern, while climate-induced burnt area increase might be limited by fuel availability in the most arid areas. While all studies agreed on the direction of changes, further comparisons on the magnitude of increase remained challenging because of heterogeneous methodological choices between projections studies (climate models, projection period, spatial scale and fire metrics). We then described three main sources of uncertainty that may affect the reliability of wildfire projections: climate projections, climate-fire models, and the influences of fuel load/structure and human related factors on the climate-fire relationships. We finally suggest research directions to address some of these issues for the purpose of refining fire danger and fire activity projections in southern Europe.

International audience; Spatial Augmented Reality (SAR) transforms real-world objects into interactive displays by projecting digital content using video projectors. SAR enables co-located collaboration immediately between multiple viewers without the need to wear any special glasses. Unfortunately, one major limitation of SAR is that visual content can only be projected onto its physical supports. As a result, displaying User Interfaces (UI) widgets such as menus and pop-up windows in SAR is very challenging. We are trying to address this limitation by extending SAR space in mid-air. In this paper, we propose Drone-SAR, which extends the physical space of SAR by projecting digital information dynamically on the tracked panels mounted on a drone. DroneSAR is a proof of concept of novel SAR User Interface (UI), which provides support for 2D widgets (i.e., label, menu, interactive tools, etc.) to enrich SAR interactive experience. We also describe the implementation details of our proposed approach.

As rats learn to search for multiple sources of food or water in a complex environment, they generate increasingly efficient trajectories between reward sites. Such spatial navigation capacity involves the replay of hippocampal place-cells during awake states, generating small sequences of spatially related place-cell activity that we call “snippets”. These snippets occur primarily during sharp-wave-ripples (SWRs). Here we focus on the role of such replay events, as the animal is learning a traveling salesperson task (TSP) across multiple trials. We hypothesize that snippet replay generates synthetic data that can substantially expand and restructure the experience available and make learning more optimal. We developed a model of snippet generation that is modulated by reward, propagated in the forward and reverse directions. This implements a form of spatial credit assignment for reinforcement learning. We use a biologically motivated computational framework known as ‘reservoir computing’ to model prefrontal cortex (PFC) in sequence learning, in which large pools of prewired neural elements process information dynamically through reverberations. This PFC model consolidates snippets into larger spatial sequences that may be later recalled by subsets of the original sequences. Our simulation experiments provide neurophysiological explanations for two pertinent observations related to navigation. Reward modulation allows the system to reject non-optimal segments of experienced trajectories, and reverse replay allows the system to “learn” trajectories that it has not physically experienced, both of which significantly contribute to the TSP behavior., Author summary As rats search for multiple sources of food in a complex environment, they generate increasingly efficient trajectories between reward sites, across multiple trials. This spatial navigation optimization behavior can be measured in the laboratory using a traveling salesperson task (TSP). This likely involves the coordinated replay of place-cell “snippets” between successive trials. We hypothesize that “snippets” can be used by the prefrontal cortex (PFC) to implement a form of reward-modulated reinforcement learning. Our simulation experiments provide neurophysiological explanations for two pertinent observations related to navigation. Reward modulation allows the system to reject non-optimal segments of experienced trajectories, and reverse replay allows the system to “learn” trajectories that it has not physically experienced, both of which significantly contribute to the TSP behavior.

In the area of sea-level rise, recent research has focused on assessing either likely or high end future sea levels, but less attention has been given to &ldquo, low-end&rdquo, sea-level projections, exploring best-case potential sea-level changes and providing the basis for estimating minimum adaptation needs. Here, we provide global and regional probabilistic sea-level projections using conservative projections of glaciers and ice-sheets melting and a selection of models from the Coupled Model Intercomparison Project phase 5 (CMIP5) delivering moderate thermal expansion. Our low-end sea-level projections are higher than previously estimated because they rely on modeling outcomes only, and do not add any expert judgement, aiming essentially at delivering more realistic upper tails. While there are good reasons to believe that our projections are excessively optimistic, they can be used as low-end sea-level projections in order to inform users with low aversion to uncertainty. Our low-end sea-level projection exceeds 0.5 m along most inhabited coasts by 2100 for business as usual greenhouse gas emissions (RCP8.5), which is relevant for adaptation practitioners as long as efficient climate change mitigation policies are not implemented. This means that without efficient climate mitigation, an acceleration of sea-level rise can hardly be avoided during the 21st century.

Evaluation of chilling requirements of cultivars of temperate fruit trees provides key information to assess regional suitability, according to winter chill, for both industry expansion and ongoing profitability as climate change progresses. Traditional methods for calculating chilling requirements use climate-controlled chambers and define chilling requirements (CR) using a fixed bud burst percentage, usually close to 50% (CR-50%). However, this CR-50% definition may estimate chilling requirements that lead to flowering percentages that are lower than required for orchards to be commercially viable. We used sweet cherry to analyse the traditional method for calculating chilling requirements (CR-50%) and compared the results with a more restrictive method, where the chilling requirement was defined by a 90% bud break level (CRm-90%). For sweet cherry, this higher requirement of flowering success (90% as opposed to 50%) better represents grower production needs as a greater number of flowers leads to greater potential yield. To investigate the future risk of insufficient chill based on alternate calculations of the chilling requirement, climate projections of winter chill suitability across Europe were calculated using CR-50% and CRm-90%. Regional suitability across the landscape was highly dependent on the method used to define chilling requirements, and differences were found for both cold and mild winter areas. Our results suggest that bud break percentage levels used in the assessment of chilling requirements for sweet cherry influence production risks of current and future production areas. The use of traditional methods to determine chilling requirements can result in an underestimation of productivity chilling requirements for tree crops like sweet cherry which rely on a high conversion of flowers to mature fruit to obtain profitable yields. This underestimation may have negative consequences for the fruit industry as climate change advances with climate risk underestimated.

The development of renewable electricity in Africa could be massive in coming decades, as a response to the rapid rising electricity demand while complying with the Paris Agreements. This study shows that in the high-resolution climate experiments of CORDEX-AFRICA, the annual mean solar potential is expected to decrease on average by 4% over most of the continent by the end of the century, reaching up to 6% over the Horn of Africa, as a direct result of decrease in solar radiation and increase in air surface temperature. These projections are associated with large uncertainties, in particular over the Sahel and the elevated terrains of eastern Africa. While the expected decrease may affect the sizing of the numerous solar projects planned in Africa for the next decades, this study suggests that it does not endanger their viability. At last, this study indicates that the design of such projects also needs to account for the non-negligible uncertainties associated with the resource.

IArticle; Book Chapter; Marine biodiversity and ecosystem services: the large gloomy shadow of climate change

International audience

The aging of people with disabilities has become, in the last forty years, a significant issue in the medico-social sector and also in our society. The lengthening of life is a positive phenomenon, a result of the efforts to professionalize the accompaniment of people with disabilities. Aging is a process, certainly irreversible, but natural. If a few people are the rare witnesses, in the 1980s, the phenomenon grows with time and becomes a demographic phenomenon. For the demographer, the notion of aging applies to a population and not to individuals. The observation of this process makes it possible to predict the trend of the changing needs of a population in the health, social and medico-social fields, but does not indicate anything about the needs of the aging person. Populations are changing, new ones are emerging and our societal system needs to adapt to new needs. The socio-demographic approach of the aging of people with disabilities proposed here tends to study the specificities of the aging population within medical and social services and institutions in the Bourgogne-Franche-Comté region. Working on this subject implies understanding but also measuring the extent of the problem., Le vieillissement des personnes en situation de handicap est devenu, au cours des quarante dernières années, une problématique prégnante non seulement du secteur médico-social mais aussi de notre société. L’allongement de la durée de la vie est un phénomène positif, résultat des efforts de professionnalisation des accompagnements des personnes en situation de handicap. Le vieillissement est un processus, certes irréversible, mais naturel. Si quelques personnes en sont les rares témoins, dans les années 1980, le phénomène prend de l’ampleur avec le temps et devient un phénomène démographique. Pour le démographe, la notion de vieillissement concerne une population et non des individus. L’observation de ce processus permet de prévoir la tendance de l’évolution des besoins d’une population dans les domaines sanitaires, sociaux et médico-sociaux, mais n’indique rien quant aux besoins de la personne vieillissante. Les populations évoluent, de nouvelles apparaissent et notre système sociétal doit s’adapter à de nouveaux besoins. L’approche socio-démographique du vieillissement des personnes en situation de handicap proposée ici tend à étudier les spécificités de la population avançant en âge au sein des établissements et services médico-sociaux de la région Bourgogne-Franche-Comté. Travailler sur ce sujet implique de comprendre, mais aussi de mesurer l’ampleur de la problématique.

© 2017 Informa UK Limited, trading as Taylor & Francis Group Governmental climate change mitigation targets are typically developed with the aid of forecasts of greenhouse-gas (GHG) emissions. The robustness and credibility of such forecasts depends, among other issues, on the extent to which forecasting approaches can reflect prevailing uncertainties. We apply a transparent and replicable method to quantify the uncertainty associated with projections of gross domestic product growth rates for Mexico, a key driver of GHG emissions in the country. We use those projections to produce probabilistic forecasts of GHG emissions for Mexico. We contrast our probabilistic forecasts with Mexico’s governmental deterministic forecasts. We show that, because they fail to reflect such key uncertainty, deterministic forecasts are ill-suited for use in target-setting processes. We argue that (i) guidelines should be agreed upon, to ensure that governmental forecasts meet certain minimum transparency and quality standards, and (ii) governments should be held accountable for the appropriateness of the forecasting approach applied to prepare governmental forecasts, especially when those forecasts are used to derive climate change mitigation targets. POLICY INSIGHTSNo minimum transparency and quality standards exist to guide the development of GHG emission scenario forecasts, not even when these forecasts are used to set national climate change mitigation targets.No accountability mechanisms appear to be in place at the national level to ensure that national governments rely on scientifically sound processes to develop GHG emission scenarios.Using probabilistic forecasts to underpin emission reduction targets represents a scientifically sound option for reflecting in the target the uncertainty to which those forecasts are subject, thus increasing the validity of the target.Setting up minimum transparency and quality standards, and holding governments accountable for their choice of forecasting methods could lead to more robust emission reduction targets nationally and, by extension, internationally.

This paper documents the accuracy of a post-correction method applied to precipitation regionalized by the Weather Research and Forecasting (WRF) Regional Climate Model (RCM) for improving simulated rainfall and feeding impact studies. The WRF simulation covers Burgundy (northeastern France) at a 8-km resolution and over a 20-year long period (1989–2008). Previous results show a strong deficiency of the WRF model for simulating precipitation, especially when convective processes are involved. In order to reduce such biases, a Quantile Mapping (QM) method is applied to WRF-simulated precipitation using the mesoscale atmospheric analyses system SAFRAN («Système d'Analyse Fournissant des Renseignements Adaptés à la Nivologie») that provides precipitation data at an 8 km resolution. Raw and post-corrected model outputs are next used to compute the soil water balance of 30 Douglas-fir and 57 common Beech stands across Burgundy, for which radial growth data are available. Results show that the QM method succeeds at reducing the model's wet biases in spring and summer. Significant improvements are also noted for rainfall seasonality and interannual variability, as well as its spatial distribution. Based on both raw and post-corrected rainfall time series, a Soil Water Deficit Index (SWDI) is next computed as the sum of the daily deviations between the relative extractible water and a critical value of 40% below which the low soil water content induce stomatal regulation. Post-correcting WRF precipitation does not significantly improve the simulation of the SWDI upon the raw (uncorrected) model outputs. Two characteristic years were diagnosed to explain this unexpected lack of improvement. Although the QM method allows producing realistic precipitation amounts, it does not correct the timing errors produced by the climate model, which is yet a major issue to obtain reliable estimators of local-scale bioclimatic conditions for impact studies. A realistic temporality of simulated precipitation is thus required before using any systematic post-correction method for appropriate climate impact assessment over temperate forests. Fil: Boulard, Damien. Universite de Bourgogne; Francia Fil: Castel, Thierry. Universite de Bourgogne; Francia Fil: Camberlin, Pierre. Universite de Bourgogne; Francia Fil: Sergent, Anne Sophie. Institut National de la Recherche Agronomique; Francia. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Patagonia Norte. Estación Experimental Agropecuaria San Carlos de Bariloche; Argentina Fil: Asse, Daphné. Crea Centre de Recherches Sur Les Ecosystèmes Daltitud; Francia Fil: Bréda, Nathalie. Institut National de la Recherche Agronomique; Francia Fil: Badeau, Vincent. Institut National de la Recherche Agronomique; Francia Fil: Rossi, Aurélien. Universite de Bourgogne; Francia Fil: Pohl, Benjamin. Universite de Bourgogne; Francia

The present work to propose a structural geological model for the Sucre municipality sector of the Araque-San Juan, where the tensional addresses study zone are estimate. The methodical used is based in the data collection of courses and dips of familiy joint, in the outcroppings measurements, taking into the account that joints are founded completely closed with a presentation of its technical origen to presenting a repetitive long exposure but none of a stratification parallel foliation from, in any case, the possible aggrupation inset will be generating some of fault surface. Computers software’s stereographic projections are used based in the Upright Dihedral method. This results are supported the vectorial method as well based in the numerical analysis. Finally to determine that the Vergence zone has a direction N89W to concern the Andean comprehensive regime but also the structuring reflecting stones with suggesting a transtensional regime, En el presente trabajo se propone un modelo geológico estructural del sector Los Araques-San Juan, donde se estima las direcciones de los esfuerzos principales en la zona estudiada. La metodología utilizada se fundamenta en la recolección de datos de rumbos y buzamientos de las familias de diaclasas, medidas en los afloramientos, teniendo en cuenta que las diaclasas se encuentren cerradas, sean de origen tectónico y que no sean paralelas a la foliación o estratificación cual fuere el caso; con el fin de agruparlas para generar las posibles superficies de falla. Se emplean para ello, software computacionales de proyecciones estereográficas basado en el método de los Diedros Rectos. Estos resultados son corroborados por el método vectorial basado en un análisis numérico. Posteriormente se estima la dirección de los esfuerzos principales actuantes a través de la combinación de pares de superficies de fallas conjugadas en el área de estudio. Finalmente se determina que la vergencia en la zona de estudio tiene una dirección N 89° W, que corresponde con el régimen compresivo andino y junto con las estructuras plasmadas en los afloramientos, se sugiere un régimen transtensivo.

After a short overview of the IPCC's contribution to the issue of climate change, this article presents the constraints linked to the willingness of the negotiators of the Paris Agreement to limit global warming to less than 2° C and even 1.5° C. Based on the fact that the current warming has already reached the threshold of 1° C, we present the important drivers of this warming and we put the problematic in a paleoclimatic context. The different scenarios for the future are outlined, emphasizing that the difference between scenarios 1.5 and 2° C is important for ecosystems and for humans. If only a small 0.5° C is left before reaching the first threshold, mitigation solutions must be implemented quickly for any purpose. Nevertheless, it is likely that the threshold of 1.5° C will be exceeded in the middle of the 21st century but that it is still possible to return below it before the end of the century, provided that, in parallel to drastic measures of decreasing fossil fuels, solutions of removal of carbon already present in the atmosphere were taken., Après un rapide tour d’horizon de l’apport du GIEC à la problématique du changement climatique, cet article présente les contraintes liées à la volonté des négociateurs de l’Accord de Paris de limiter le réchauffement planétaire à moins de 2° C et même 1,5° C. Partant du constat que le réchauffement actuel a déjà atteint le seuil de + 1° C, on présente les forçages importants de ce réchauffement et on replace la problématique dans un contexte paléoclimatique. Les différents scénarios pour le futur sont esquissés en insistant sur le fait que la différence entre les scénarios + 1,5 et + 2° C est importante pour les écosystèmes et pour les humains. S’il ne reste plus qu’un petit 0,5° C avant d’atteindre le premier seuil, des solutions d’atténuation du réchauffement doivent être mises en place rapidement quel que soit l’objectif. Il reste malgré tout vraisemblable que le seuil de 1,5° C sera dépassé au milieu de 21ème siècle mais qu’il est encore possible de revenir en dessous à la fin du siècle, à condition d’accompagner les mesures drastiques de diminution des énergies fossiles par des mesures d’absorption du carbone déjà présent dans l’atmosphère., Guiot Joël. Limiter l’augmentation des températures bien en dessous de 2°C : est-ce un objectif atteignable ?. In: Revue Juridique de l'Environnement, numéro spécial, 2017. Après l'accord de Paris, quels droits face au changement climatique ? Colloque annuel de la Société Française pour le Droit de l'Environnement, 29 et 30 juin 2017 à Aix-en-Provence. pp. 23-32.

The present work to propose a structural geological model for the Sucre municipality sector of the Araque-San Juan, where the tensional addresses study zone are estimate. The methodical used is based in the data collection of courses and dips of familiy joint, in the outcroppings measurements, taking into the account that joints are founded completely closed with a presentation of its technical origen to presenting a repetitive long exposure but none of a stratification parallel foliation from, in any case, the possible aggrupation inset will be generating some of fault surface. Computers software’s stereographic projections are used based in the Upright Dihedral method. This results are supported the vectorial method as well based in the numerical analysis. Finally to determine that the Vergence zone has a direction N89W to concern the Andean comprehensive regime but also the structuring reflecting stones with suggesting a transtensional regime, En el presente trabajo se propone un modelo geológico estructural del sector Los Araques-San Juan, donde se estima las direcciones de los esfuerzos principales en la zona estudiada. La metodología utilizada se fundamenta en la recolección de datos de rumbos y buzamientos de las familias de diaclasas, medidas en los afloramientos, teniendo en cuenta que las diaclasas se encuentren cerradas, sean de origen tectónico y que no sean paralelas a la foliación o estratificación cual fuere el caso; con el fin de agruparlas para generar las posibles superficies de falla. Se emplean para ello, software computacionales de proyecciones estereográficas basado en el método de los Diedros Rectos. Estos resultados son corroborados por el método vectorial basado en un análisis numérico. Posteriormente se estima la dirección de los esfuerzos principales actuantes a través de la combinación de pares de superficies de fallas conjugadas en el área de estudio. Finalmente se determina que la vergencia en la zona de estudio tiene una dirección N 89° W, que corresponde con el régimen compresivo andino y junto con las estructuras plasmadas en los afloramientos, se sugiere un régimen transtensivo.

Parmi les gaz à effet de serre, les gaz fluorés ont l'originalité d'être pour certains réglementés par le protocole de Montréal, d'autres, par le protocole de Kyoto. Si l'on considère la transition des CFC aux HFC, l'ambition de réduction Facteur 4 à l'horizon 2050 par rapport à 1990 des émissions de gaz fluorés utilisés dans les secteurs du froid et de la climatisation est tout à fait réalisable.

International audience; Is the goal of keeping the increase of temperatures below 2°C achievable? After a short overview of the IPCC's contribution to the issue of climate change, this article presents the constraints linked to the willingness of the negotiators of the Paris Agreement to limit global warming to less than 2°C and even 1.5°C. Based on the fact that the current warming has already reached the threshold of 1°C, we present the important drivers of this warming and we put the problematic in a paleoclimatic context. The different scenarios for the future are outlined, emphasizing that the difference between scenarios 1.5 and 2°C is important for ecosystems and for humans. If only a small 0.5°C is left before reaching the first threshold, mitigation solutions must be implemented quickly for any purpose. Nevertheless, it is likely that the threshold of 1.5°C will be exceeded in the middle of the 21st century but that it is still possible to return below it before the end of the century, provided that, in parallel to drastic measures of decreasing fossil fuels, solutions of removal of carbon already present in the atmosphere were taken.; Après un rapide tour d'horizon de l'apport du GIEC à la problématique du changement climatique, cet article présente les contraintes liées à la volonté des négociateurs de l'Accord de Paris de limiter le réchauffement planétaire à moins de 2°C et même 1,5°C. Partant du constat que le réchauffement actuel a déjà atteint le seuil de +1°C, on présente les forçages importants de ce réchauffement et on replace la problématique dans un contexte paléoclimatique. Les différents scéna-rios pour le futur sont esquissés en insistant sur le fait que la différence entre les scénarios +1,5 et +2°C est importante pour les écosystèmes et pour les humains. S'il ne reste plus qu'un petit 0,5°C avant d'atteindre le premier seuil, des solutions d'atténuation du réchauffement doivent être mises en place rapidement quel que soit l'objectif. Il reste malgré tout vraisemblable que le seuil de 1,5°C sera dépassé au milieu de 21 ème siècle mais qu'il est encore possible de revenir en dessous à la fin du siècle, à condition d'accompagner les mesures drastiques de diminution des énergies fossiles par des mesures d'absorption du carbone déjà présent dans l'atmosphère

Nowadays, Public Health is more and more interested in the neuro-degenerative chronic diseases related to the ageing such as Dementia or Parkinson’s disease. These pathologies cannot be prevented or cured and cause a progressive deterioration of health, requiring specific cares. The current demographic situation suggests a continuous ageing of the population and a rise of the life expectancy. As consequence of this, the economic, social and demographic burden related to these diseases will worsen in years to come. That is why, developing statistical models, which allow to make projections and to estimate the future burden of chronic diseases via several health indicators, is becoming of paramount importance. Furthermore, it would be interesting to give projections, according to hypothetical scenarios, which could be set up (e.g. a new treatment), to estimate the impact of such Public health intervention, but also to take into account modifications in disease incidence due, for example, to behavior changes. To attend this objective, an approach was proposed by Joly et al. 2013, using the illness-death model under Markovian hypothesis. Such approach has shown to be particularly adapted in this context, since it allows to consider the competive risk existing between the risk of death and the risk to develop the disease (for anon-diseased subject). On one hand, projections made by using this model take advantage of including national demographic projections to better consider the mortality trends over time. Moreover, the approach proposes to carefully model mortality, distinguishing overall mortality, non-diseased and diseased mortality trends. All the work of this thesis have been developed based on this model. In a first part, the hypotheses of the existing model are improved or modified in order to both :consider the evolution of disease incidence over time ; pass from a Markov to a semi-Markov hypothesis, which allows to model the mortality among diseased subjects depending on the time spent with the disease. In a second part, the initial method, allowing to take into account the impact of an intervention, but with many restrictive assumptions, is developed and generalized for more flexible interventions. Then, the mathematical/statistical expressions of relevant health indicators are developed in this context to have a panel of projections giving a better assessment of the future disease burden. The main application of this work concerns projections of Dementia. However, by applying these models to Parkinson’s disease, we propose methods which allows to adapt our approach to other types of data.; De nos jours, la Santé Publique porte de plus en plus d’intérêts aux maladies chroniques neuro-dégénératives liées au vieillissement telles que la démence ou la maladie de Parkinson. Ces pathologies ne peuvent ni être évitées ni guéries et occasionnent une détérioration progressive de la santé des malades requérant donc des soins spécifiques. Le contexte démographique actuel laisse entrevoir un vieillissement de la population et un allongement de l’espérance de vie continus, ce qui aura pour conséquence majeure d’aggraver le fardeau économique, social et démographique de ces maladies dans les années à venir. C’est pourquoi, dans l’optique d’anticiper les problèmes à venir, il est important de développer des modèles statistiques permettant de faire des projections et d’évaluer le fardeau futur de ces maladies via divers indicateurs de santé. De plus, il est intéressant de pouvoir donner des projections,en fonction de scénarios potentiels, qui pourraient être mis en place (e.g. un nouveau traitement), afin d’évaluer l’impact qu’aurait une telle intervention de Santé Publique, mais aussi de prendre en compte une variation de l’incidence due, par exemple, à des changements de comportement. Une approche utilisant le modèle illness-death sous une hypothèse Markovienne a été proposée par Joly et al. 2013 pour répondre à cet objectif. Cette approche est particulièrement adaptée dans ce contexte, car elle permet, notamment, de prendre en compte le risque compétitif qui existe entre devenir malade ou décéder (pour un individu non-malade). L’utilisation de ce modèle pour faire des projections a l’avantage, d’une part, de faire intervenir des projections démographiques nationales pour mieux capter l’évolution de la mortalité au cours du temps, et d’autre part, de proposer une modélisation adaptée de la mortalité (en distinguant la mortalité des malades, des non-malades et générale). C’est sur la base de ce modèle que découle tout le travail de cette thèse. Dans une première partie, les hypothèses du modèle existant ont été améliorées ou modifiées dans le but de considérer l’évolution de l’incidence de la maladie au cours du temps,puis de passer d’un modèle Markovien à un modèle semi-Markovien afin de modéliser la mortalité des malades en fonction de la durée passée avec la maladie. Dans une deuxième partie, la méthode initiale, permettant de considérer l’impact d’une intervention mais avec des hypothèses restrictives, a été développée et généralisée pour prendre en compte des interventions plus flexibles. Puis, les expressions mathématiques/statistiques d’indicateurs de santé pertinents ont été développées dans ce contexte dans le but d’avoir un panel de projections permettant une meilleure évaluation du fardeau futur de la maladie. L’application principale de ce travail a porté sur des projections concernant la démence. Cependant, en appliquant ces modèles à la maladie de Parkinson, nous avons proposé des méthodes permettant d’adapter notre approche à d’autres types de données.

International audience; La Carte à la une d'octobre 2016 invite à réfléchir sur la fabrique de la carte, le choix d'une projection et de la méthode de représentation par anamorphose, à partir de la production mondiale d'articles scientifiques. C'est aussi un regard sur une économie de la connaissance mondialisée et multipolarisée.

Peatlands are widely present in northern latitudes and especiallyin permafrost regions. They contain a high carbon stock and are one ofthe greatest natural sources of methane. Their representation in a climate model is crucial to improve the one of the carbon cycle. Moreover, the contribution of methanepeatland emissions remains uncertain.Methane emissions from peatlands strongly depend on the climate and are influenced primarily by temperature and soil moisture. Meanwhile, climate change is particularlysevere at these latitudes and leads to thawing permafrost with increasing the active layer depth. This large carbon reservoir may be partially mobilized and emitted asCO2 or CH4, depending on hydrological conditions at the surface.The aim of this PhD thesis is to represent northern peatlands in the ORCHIDEE land surface model. This development is carried out in the version of the model that incorporatesprocesses in high latitudes such as the soil freezing. Peatlands are represented by a specific hydrological scheme which improves the exchange of energy and water. The difficulty isbased on the representation of local peatlands processes across a global climate model. Some biological properties were also considered to represent bettervegetation of these environments. To do so, peatlands are integrated as a new type ofvegetation and represented by a fraction of a grid, based on observations. Thehydrological behaviour and the impact of this integration are estimated at the boreal scale as well asregionally. This development then allows estimate changes in the hydrology of peatlands due to global warming. Studying the changes in hydrology of peatlands by the end of th 21st century will improve the prediction of future changes in their CH4 emissions.This development work was then applied to determine the evolution of methane emissions. Peatlands are one of the largest natural sources of methane and control more than 70% interannual variability of atmospheric concentration of CH4. Methane emissions result from various physical and biological processes such as methanogenesis and the methanotrophy. To represent these processes, a flux density model, integratedin ORCHIDEE, was adapted for peatlands to estimate their methane emissions. The evolution of these emissions is studied between the early 20th and late 21st centuries under different climate scenarios., Les tourbières sont largement présentes dans les hautes latitudes nord et plus particulièrement dans les régions de pergélisols. Elles contiennent un important stock de carbone et constituent l’une des plus grandes sources naturelles de méthane. Leur représentation dans un modèle de climat estalors primordiale pour améliorer celle du cycle du carbone. De plus, la contribution des émissions de méthane des tourbières reste encore incertaine et de nombreuses incertitudes persistent. Les émissions de méthane des tourbières dépendent fortement du climat et sont influencées principalement par la température et l’humidité du sol. Parallèlement, le réchauffement climatique particulièrement prononcé à ces latitudes conduit au dégel des pergélisols avec une augmentation de la profondeur de la couche active. Ce grand réservoir de carbone peut être partiellement mobilisé et émis sous forme de CO2 ou CH4, en fonction des conditions hydrologiques à la surface.L’objectif de ces travaux de thèse consiste à représenter les tourbières des hautes latitudes dansle modèle de surface ORCHIDEE. Ce développement est effectué dans la version du modèle qui intègreles processus des hautes latitudes tels que le gel des sols. Les tourbières sont représentées parun schéma hydrologique spécifique ce qui améliore les échanges en énergie et en eau. La difficultérepose sur la représentation des processus locaux des tourbières à l’échelle d’un modèle de climatglobal. Certaines propriétés biologiques ont également été prises en compte afin de mieux représenter la végétation de ces milieux. Pour cela, les tourbières sont intégrées comme un nouveau type devégétation et représentées par une fraction de grille, basée sur des observations. Le comportement hydrologique et l’impact de cette intégration sont évalués à échelle des hautes latitudes ainsi qu’à échelle régionale. Ce développement permet d’estimer ensuite l’évolution de l’hydrologie des tourbières suite au réchauffement climatique. Les changements de l’hydrologie des tourbières d’ici la fin du siècle permettent de mieux évaluer les variations futures de leurs émissions de CH4.Ce travail de développement a ensuite été appliqué pour déterminer l’évolution des émissions deméthane. Les tourbières constituent l’une des plus grandes sources naturelles de méthane et contrôlentà plus de 70 % la variabilité interannuelle de la concentration atmosphérique de CH4. Les émissionsde méthane résultent de différents processus physiques et biologiques tels que la méthanogénèse etla méthanotrophie. Pour représenter ces processus, un modèle de densité de flux existant, intégré dans ORCHIDEE, a été adapté pour les tourbières afin d’estimer les émissions de méthane des tourbières des hautes latitudes. L’évolution de ces émissions est étudiée entre le début du 20ème et la fin du 21ème siècles selon différents scénarios climatiques.

International audience; Pour anticiper les changements potentiels dans la quantité d'eau disponible dans le bassinversant montagneux Rheraya (près de Marrakech), il est important de connaître l'évolution decette ressource en relation avec les changements climatiques. Dans cette étude, nous utilisonsle modèle GR4J avec un module de neige avec des séries chronologiques de précipitations etdébit (1989-2009). Le modèle a été calibré et validé avec succès sur diverses périodes. Ensuite,nous avons utilisé un ensemble de 5 modèles climatiques régionaux (RCM) fournis par leprogramme Med-CORDEX avec une méthode de perturbation par quantiles pour simuler desscénarios futurs de prévisions des débits.L'évaluation des précipitations simulées par les RCMs montre une forte sous-estimation de ~50%, mais une bonne reproduction du cycle pour les températures. Les projections des 5 RCMsselon les deux scénarios RCP4.5 et RCP8.5 montrent une hausse des températures (+1.4°, +2.6°)conjointement à une baisse des précipitations totales (-19%, 31%). Concernant la modélisationhydrologique avec GR4J, des résultats stables sont obtenus pour la calibration et la validationquelle que soit la période choisie, avec une erreur maximale de 15% dans la validation sur lesdébits mensuels. Les prévisions des débits (2041-2062) présentent une forte diminution prévuedu ruissellement de surface (-30%, -60%) et des baisses significatives des niveaux des réservoirsenneigées, liées à la diminution des précipitations et l'augmentation de la température.

Indexation en cours; International audience; Odorant receptors (ORs) control several aspects of cell fate in olfactory sensory neurons (OSNs), including singular gene choice and axonal identity. The mechanisms of OR-induced axon guidance have been suggested to principally rely on G-protein signalling. Here, we report that for a subset of OSNs, deleting G proteins or altering their levels of signalling does not affect axonal identity. Signalling-deficient ORs or surrogate receptors that are unable to couple to Gs/Golf still provide axons with distinct identities and the anterior-posterior targeting of axons does not correlate with the levels of cAMP produced by genetic modifications. In addition, we refine the models of negative feedback by showing that ectopic ORs can be robustly expressed without suppressing endogenous gene choice. In conclusion, our results uncover a new feature of ORs, showing that they can instruct axonal identity and regulate olfactory map formation independent of canonical G-protein signalling and cAMP production.

La géométrie intégrale, aussi appelée théorie des probabilités géométriques, a accompagné pendant plus de deux siècles le développement des probabilités, de la théorie de la mesure et de la géométrie. Elle commence pour nous en 1777, date de la publication du « traité d'arithmétique morale » de Buffon. Ce n'est que presque un siècle plus tard que Crofton explicitera ce que veut dire mettre une mesure sur un ensemble continu comme l'ensemble des droites. Le sens de la formule de Cauchy-Crofton « la longueur d'une courbe plane est proportionnelle à la mesure pondérée de l'ensemble des droites qui la coupent », est maintenant clair. Au début du vingtième siècle, la géométrie intégrale commence à considérer les formes des objets étudiés. Minkowski, en 1901, a trouvé la première relation entre une intégrale de courbure sur ∂Q et la mesure de l'ensemble des plans coupant Q. Steiner, Blaschke, Chern ont obtenu de nombreux résultats dans le même esprit concernant les courbes et les surfaces. La topologie est entrée dans le jeu pendant la seconde moitié du vingtième siècle. Toutefois le premier résultat de géométrie intégrale faisant intervenir la topologie est celui montré en 1929 par Fenchel : la courbure totale d'une courbe fermée plongée dans l'espace euclidien R3 est supérieure ou égale à 2π. Nous savons maintenant que si, de plus, la courbe est nouée, cette courbure totale est supérieure à 4π, ce qui indique qu'une topologie plus compliquée exige une géométrie plus compliquée. Nous montrerons bien d'autres exemples, dans des espaces euclidiens ou de courbure constante. Nous présenterons ensuite des résultats du même type concernant les courbes complexes et les feuilletages de variétés de courbure constante. Jusqu'à maintenant, il fallait que l'espace ambient soit muni d'une métrique. La géométrie locale des courbes, surfaces ou feuilletages que nous observions était mesurée en utilisant des fonctions de courbure. La géométrie conforme se comporte souvent différemment. Il faut souvent considérer la géométrie locale de paires de points. La contrepartie globale sera mesurée en considérant la position de ces courbes ou surfaces relativement à des sphères. La non-compacité de l'ensemble des 2-sphères de S3 est une difficulté supplémentaire. Nous décrirons les premiers résultats obtenus dans cette direction.

National audience

Nowadays, Public Health is more and more interested in the neuro-degenerative chronic diseases related to the ageing such as Dementia or Parkinson’s disease. These pathologies cannot be prevented or cured and cause a progressive deterioration of health, requiring specific cares. The current demographic situation suggests a continuous ageing of the population and a rise of the life expectancy. As consequence of this, the economic, social and demographic burden related to these diseases will worsen in years to come. That is why, developing statistical models, which allow to make projections and to estimate the future burden of chronic diseases via several health indicators, is becoming of paramount importance. Furthermore, it would be interesting to give projections, according to hypothetical scenarios, which could be set up (e.g. a new treatment), to estimate the impact of such Public health intervention, but also to take into account modifications in disease incidence due, for example, to behavior changes. To attend this objective, an approach was proposed by Joly et al. 2013, using the illness-death model under Markovian hypothesis. Such approach has shown to be particularly adapted in this context, since it allows to consider the competive risk existing between the risk of death and the risk to develop the disease (for anon-diseased subject). On one hand, projections made by using this model take advantage of including national demographic projections to better consider the mortality trends over time. Moreover, the approach proposes to carefully model mortality, distinguishing overall mortality, non-diseased and diseased mortality trends. All the work of this thesis have been developed based on this model. In a first part, the hypotheses of the existing model are improved or modified in order to both :consider the evolution of disease incidence over time ; pass from a Markov to a semi-Markov hypothesis, which allows to model the mortality among diseased subjects depending on the time spent with the disease. In a second part, the initial method, allowing to take into account the impact of an intervention, but with many restrictive assumptions, is developed and generalized for more flexible interventions. Then, the mathematical/statistical expressions of relevant health indicators are developed in this context to have a panel of projections giving a better assessment of the future disease burden. The main application of this work concerns projections of Dementia. However, by applying these models to Parkinson’s disease, we propose methods which allows to adapt our approach to other types of data., De nos jours, la Santé Publique porte de plus en plus d’intérêts aux maladies chroniques neuro-dégénératives liées au vieillissement telles que la démence ou la maladie de Parkinson. Ces pathologies ne peuvent ni être évitées ni guéries et occasionnent une détérioration progressive de la santé des malades requérant donc des soins spécifiques. Le contexte démographique actuel laisse entrevoir un vieillissement de la population et un allongement de l’espérance de vie continus, ce qui aura pour conséquence majeure d’aggraver le fardeau économique, social et démographique de ces maladies dans les années à venir. C’est pourquoi, dans l’optique d’anticiper les problèmes à venir, il est important de développer des modèles statistiques permettant de faire des projections et d’évaluer le fardeau futur de ces maladies via divers indicateurs de santé. De plus, il est intéressant de pouvoir donner des projections,en fonction de scénarios potentiels, qui pourraient être mis en place (e.g. un nouveau traitement), afin d’évaluer l’impact qu’aurait une telle intervention de Santé Publique, mais aussi de prendre en compte une variation de l’incidence due, par exemple, à des changements de comportement. Une approche utilisant le modèle illness-death sous une hypothèse Markovienne a été proposée par Joly et al. 2013 pour répondre à cet objectif. Cette approche est particulièrement adaptée dans ce contexte, car elle permet, notamment, de prendre en compte le risque compétitif qui existe entre devenir malade ou décéder (pour un individu non-malade). L’utilisation de ce modèle pour faire des projections a l’avantage, d’une part, de faire intervenir des projections démographiques nationales pour mieux capter l’évolution de la mortalité au cours du temps, et d’autre part, de proposer une modélisation adaptée de la mortalité (en distinguant la mortalité des malades, des non-malades et générale). C’est sur la base de ce modèle que découle tout le travail de cette thèse. Dans une première partie, les hypothèses du modèle existant ont été améliorées ou modifiées dans le but de considérer l’évolution de l’incidence de la maladie au cours du temps,puis de passer d’un modèle Markovien à un modèle semi-Markovien afin de modéliser la mortalité des malades en fonction de la durée passée avec la maladie. Dans une deuxième partie, la méthode initiale, permettant de considérer l’impact d’une intervention mais avec des hypothèses restrictives, a été développée et généralisée pour prendre en compte des interventions plus flexibles. Puis, les expressions mathématiques/statistiques d’indicateurs de santé pertinents ont été développées dans ce contexte dans le but d’avoir un panel de projections permettant une meilleure évaluation du fardeau futur de la maladie. L’application principale de ce travail a porté sur des projections concernant la démence. Cependant, en appliquant ces modèles à la maladie de Parkinson, nous avons proposé des méthodes permettant d’adapter notre approche à d’autres types de données.

Nowadays, more and more data of different kinds is becoming available. Various datasets contain valuable information that could help to solve many practical problems or to lead to a breakthrough in fundamental science. But how can one extract these precious pieces of information? Formal concept analysis (FCA) and pattern structures are theoretical frameworks that allow dealing with an arbitrary structured data. But how can one put it into practice? Furthermore, the number of concepts, i.e., elementary pieces of information, extracted by FCA is typically huge. To deal with this problem one can either simplify the data representation, which can be done by projections of pattern structures, or by introducing constraints to select the most relevant concepts. What is the best data simplification? How to find concepts efficiently satisfying a given constraint? These are the questions that we address in this work. The manuscript starts with application of FCA to mining important pieces of information from molecular structures. These molecular structures are encoded as sets of attributes. Even for this simple encoding and without any additional constraints, FCA is able to extract important pieces of information from small datasets. With the growth of dataset size good constraints begin to be essential. For that we explore stability of a concept, a well-founded formal constraint. We show experimentally that it is a good choice and apply it to analyze a dataset of mutagenetic chemical substances. Finding stable concepts in this dataset allows us finding new possible mutagenetic candidates that can be further interpreted by chemists.However for more complex cases, the simple attribute representation of data is not enough. Correspondingly, we turn to pattern structures that can deal with many different kinds of descriptions. The important point about pattern structures is that they allow data simplification by means of projections. We extend the original formalism of projections to have more freedom in data simplification. We show that this extension is essential for analyzing patient trajectories, describing patients hospitalization histories. Indeed, patient trajectories are sequences of hospitalizations and every hospitalization is described by a heterogeneous description. This data is very rich and hence, produce a lot of concepts. The new type of projections allows efficient reduction of concept space and in combination with stability constraints can find important common trajectories. In addition, projections are useful to correct linked open data, a data that is distributed all over the world and that can be enriched by any person. The errors are inevitable but some of them can be efficiently found by an approach based on pattern structures. Yet another application of pattern structures is mining of drug-drug interactions from text corpuses. Based on a text of corpuses we are able to find and explain syntactic structures encoding this kind of relation.So far pattern structures do not allow direct finding of patterns satisfying the stability constraint. Correspondingly, the manuscript ends by an original and very efficient approach that enables to mine stable patterns directly. This approach is called Σοφια and is able to find the best stable patterns in polynomial time. The efficiency is essential for mining large datasets and this highlights the importance of Σοφια. We evaluate this new algorithm on several datasets and the experiments show the significant improvement of Σοφια w.r.t. its competitors forattribute and interval tuple data. Moreover it open a new direction of research for mining different types of patterns in polynomial time that is very important in the world of large data.; Aujourd’hui de plus en plus de données de différents types sont accessibles. Ces données variées contiennent des informations précieuses qui peuvent aider à résoudre des problèmes pratiques ou servir à la science fondamentale. Mais comment peut-on extraire cette information précieuse ? L’Analyse Formelle de Concepts (AFC) et les pattern structures sont des systèmes formels qui permettent de traiter les données ayant une structure complexe. Mais comment peut-on les appliquer en pratique ? De plus, le nombre de concepts, i.e., de pièces élémentaires d’information, trouvé par l’AFC est fréquemment très grand. Pour faire face à ce problème, on peut simplifier la représentation des données, soit par projection de pattern structures, soit par introduction de contraintes pour sélectionner les concepts les plus pertinents. Quelle est la meilleure simplification de données ? Comment peut-on efficacement trouver les concepts satisfaisant une contrainte donnée ? Ce sont les questions que nous abordons dans cette thèse.Le manuscrit commence avec l’application de l’AFC à l’exploration de structures moléculaires et la recherche de structures particulières. Ces structures moléculaires sont codées comme des ensembles d’attributs. Même pour ce codage simple et sans contraintes supplémentaires, l’AFC est capable d’extraire des informations importantes dans de petits ensembles de données. Avec l’augmentation de la taille des ensembles de données, de bonnes contraintes deviennent essentielles. Pour cela on explore la stabilité d’un concept. La stabilité est une contrainte formelle bien-fondée. On montre expérimentalement que c’est un bon choix et on l’applique à l’exploration d’un ensemble de données de substances chimiques mutagènes. La recherche de concepts stables dans cet ensemble de données nous a permis de trouver de nouveaux candidats mutagènes potentiels qui peuvent être interprétés par les chimistes.Cependant, pour les cas plus complexes, la représentation simple par des attributs binaires ne suffit pas. En conséquence, on se tourne vers des pattern structures qui peuvent traiter différents types de données complexes. Le point important sur les pattern structures est qu’elles permettent la simplification des données au moyen de projections. On étend le formalisme original des projections pour avoir plus de liberté dans la manipulation de données. On montre que cette extension est essentielle pour analyser les trajectoires de patients décrivant l’historique de l’hospitalisation des patients. En effet, les trajectoires de patients sont des séquences d’hospitalisations et chaque hospitalisation est décrite par une description hétérogène. Ces données sont très riches et donc produisent un grand nombre de concepts. Le nouveau type de projection permet une réduction efficace de la notion d’espace et en combinaison avec des contraintes de stabilité on peut trouver des trajectoires communes importantes. En outre, les projections sont utiles pour corriger et compléter les données liées (linked open data) où les erreurs sont inévitables. On peut efficacement trouver certaines erreurs avec une approche à base de pattern structures. Une autre application des pattern structures est la recherche des interactions médicamenteuses dans un corpus de textes. On est capable d’extraire et d’expliquer les structures syntaxiques codant ce genre des relations. Les approches présentées jusque là ne permettent pas la découverte directe de motifs sous la contrainte de stabilité. En conséquence, le manuscrit se termine par une approche originale et très efficace qui permet de trouver directement des motifs stables. Cette approche est appelée Σοφια et est capable de trouver les meilleurs modèles stables en temps polynomial. L’efficacité est essentielle pour l’analyse de grands ensembles de données et cela souligne l’importance de Σοφια. On évalue ce nouvel algorithme sur plusieurs ensembles de données et les expériences montrent l’amélioration significative de Σοφια par rapport à ses concurrents pour les données binaires et des n-uplets d’intervalles. En outre, il ouvre une nouvelle direction de recherche pour l’exploitation de différents types de motifs en temps polynomial ce qui est très important dans le monde des mégadonnées.

Anticiper la croissance à long terme des dépenses de santé constitue un des volets des exercices de surveillance budgétaire qui sont régulièrement menés à différents niveaux, notamment dans le cadre européen. Cette projection peut se faire à l’aide de maquettes macroéconomiques raisonnant à un niveau très agrégé. Mais l’exercice peut aussi se faire par microsimulation, ce qui offre un plus grand potentiel en termes de variantes et de types de résultats. La contrepartie est évidemment une certaine complexité puisqu’il faut modéliser des trajectoires individuelles d’état de santé et la distribution des dépenses associées plutôt que des valeurs moyennes. Cet article présente les premières étapes de la construction d’un modèle de ce type, appliqué aux dépenses de soins de ville. Ce modèle comprend deux modules. Le premier est un module «épidémiologique » qui projette un indicateur dichotomique de bonne / mauvaise santé obtenu en croisant données de santé subjectives et objectives. Cet indicateur est évalué sur le panel de l’enquête santé et protection sociale (ESPS) allant de 2002 à 2008. Ce panel permet d’estimer les probabilités de passage entre bonne et mauvaise santé ainsi que les probabilités de décès différenciées selon l’état de santé. Ce sont ces probabilités qui sont ensuite utilisées pour faire vieillir progressivement l’échantillon de 2008, à l’horizon de 2032. Une fois projetés les états de santé individuels, le second module simule les dépenses qui leur sont associées, à l’aide d’une approche séquentielle simulant d’abord le fait d’avoir une dépense non nulle, puis le niveau de cette dépense si elle est positive. L’articulation de ces deux modules est illustrée par quelques projections exploratoires. Ils ont été conçus pour être applicables à d’autres données de base. Ils pourront aussi être couplés avec des outils de microsimulation appliqués aux autres aspects du vieillissement démographique, principalement les retraites., Geay Charlotte, de Lagasnerie Grégoire, Larguem Makram. Intégrer les dépenses de santé dans un modèle de microsimulation dynamique : le cas des dépenses de soins de ville. In: Economie et statistique, n°481-482, 2015. Microsimulation appliquée aux politiques fiscales et sociales. pp. 211-234.

National audience

International audience; This works aims at providing a understanding of the different types of modelling uncertainties associated with future low-flow projections. Hydrological projections come indeed at the bottom of the well-known cascade of uncertainty and therefore potentially integrate all types of modeling uncertainties related to both climate and hydrological. The specificity of low flow characteristics is their tight dependency on catchment processes, suggesting a non negligible contribution of the hydrological modelling step to the overall uncertainty. This study builds on an extensive top-down climate impact approach set up within the R2D2-2050 project. This integrated assessment project aims at informing water resource adaptation strategies for the Durance river basin located in the Southern French Alps, by confronting future hydroclimate projections to prospective scenarios of water demand and water use. Future water resource estimates have been based on 11 runs from 4 GCMs from the ENSEMBLES project under the A1B emissions scenario. These large-scale projections have been further statistically downscaled with 3 probabilistic methods based on the k-nearest neighbours resampling approach, leading to 330 spatially distributed climate projections. Downscaled projections have then been used as forcings to 6 diverse hydrological models, from global conceptual to physically-based fully distributed, in order to derive transient hydrological projections from 1961 to 2065 for up to 25 stations over the basin. Most of the Durance subcatchments are under the influence of both the Alpine and Mediterranean climates, which leads to two distinct periods of low flows, one in winter when precipitation is stored as snowpack and one in late summer after the snowmelt. Analyses have therefore been applied separately to the two periods to infer the future evolution of low flows characteristics and its consistency among the range of available projections. Several analysis of variance (ANOVA) frameworks have further been applied to quantify the respective contributions of climate and hydrological modeling uncertainties on the results and their evolution over time. Results first show contrasted evolutions according to the season and the catchment, with little evolution in winter low flows for high-elevation catchments, and a dramatic decrease in summer low flows over the whole basin. The contribution of the hydrological modelling step to the overall uncertainty is moreover limited in winter, but high in summer with a pronounced increase over time. This last result critically suggests a divergence of climate change responses between the hydrological models in terms of summer low flows, potentially due to difference in the implementation of snowmelt processes.

International audience; Increases in the production of terpene-and phenolic-like compounds in plant species under abiotic stress conditions have been interpreted in physiological studies as a supplementary defense system due to their capacity to limit cell oxidation. From an ecological perspective however, these increases are only expected to confer competitive advantages if they do not imply a significant cost for the plant, that is, growth reduction. We investigated shifts of isoprene emissions, and to a lesser extent phenolic compound concentration, of Quercus pubescens Willd. from early leaf development to leaf senescence under optimal watering (control: C), mild and severe water stress (MS, SS). The impact of water stress was concomitantly assessed on plant physiological (chlorophyll fluorescence, stomatal conductance, net photosynthesis, water potential) functional (relative leaf water content, leaf mass per area ratio) and growth (aerial and root biomass) traits. Growth changes allowed to estimate the eventual costs related to the production of isoprene and phenolics. The total phenolic content was not modified under water stress whereas isoprene emissions were promoted under MS over the entire growing cycle despite the decline of P n by 35%. Under SS, isoprene emissions remained similar to C all over the study despite the decline of Pn by 47% and were thereby clearly uncoupled to Pn leading to an overestimation of the isoprene emission factor by 44%. Under SS, maintenance of isoprene emissions and phenolic compound concentration resulted in very significant costs for the plants as growth rates were very significantly reduced. Under MS, increases of isoprene emission and maintenance of phenolic compound concentration resulted in moderate growth reduction. Hence, it is likely that investment in isoprene emissions confers Q. pubescens an important competitive advantage during moderate but not severe periods of water scarcity. Consequences of this response for air quality in North Mediterranean areas are also discussed.

The purpose of this thesis is to study a numerical method for backward doubly stochastic differential equations (BDSDEs in short). In the last two decades, several methods were proposed to approximate solutions of standard backward stochastic differential equations. In this thesis, we propose an extension of one of these methods to the doubly stochastic framework. Our numerical method allows us to tackle a large class of nonlinear stochastic partial differential equations (SPDEs in short), thanks to their probabilistic interpretation. In the last part, we study a new particle method in the context of shielding studies., L’objectif de cette thèse est l’étude d’un schéma numérique pour l’approximation des solutions d’équations différentielles doublement stochastiques rétrogrades (EDDSR). Durant les deux dernières décennies, plusieurs méthodes ont été proposées afin de permettre la résolution numérique des équations différentielles stochastiques rétrogrades standards. Dans cette thèse, on propose une extension de l’une de ces méthodes au cas doublement stochastique. Notre méthode numérique nous permet d’attaquer une large gamme d’équations aux dérivées partielles stochastiques (EDPS) nonlinéaires. Ceci est possible par le biais de leur représentation probabiliste en termes d’EDDSRs. Dans la dernière partie, nous étudions une nouvelle méthode des particules dans le cadre des études de protection en neutroniques.

International audience; In this paper, we are interested in the analysis of sequential data and we propose an original framework based on FCA. For that, we introduce sequential pattern structures, an original specification of pattern structures for dealing with sequential data. Sequential pattern structures are given by a subsumption operation between set of sequences, based on subsequence matching. To avoid a huge number of resulting concepts, domain knowledge projections can be applied. The original definition of projections is revised in order to operate on sequential pattern structures in a meaningful way. Based on the introduced definition, several projections of sequential pattern structures involving domain or expert knowledge are defined and discussed. This projections are evaluated on a real dataset on care trajectories where every hospitalization is described by a heterogeneous tuple with different fields. The evaluation reveals interesting concepts and justify the usage of introduced projections of sequential pattern structures. This research work provides a new and efficient extension of FCA to deal with complex data, which can be an alternative to the analysis of sequential datasets.

[To understand the demographics of Africa as a whole or of its sub-Saharan part, put into perspective with that of Europe is éclaicant using data supplied by the international databases. However, before commenting on the results then analyzed in a prospective mind, it is important to show some humility given the fact that a number of demo-graphic data for Africa are estimates only.]; Pour bien comprendre l'évolution démographique de l'Afrique dans son ensemble ou de sa partie subsaharienne, une mise en perspective avec celle de l'Europe est éclai-rante grâce aux données livrées par les banques de données internationales. Toutefois, avant de commenter les résultats puis de les analyser dans un esprit prospectif, il importe de faire preuve d'une certaine humilité compte tenu du fait que nombre de données dé-mographiques concernant l'Afrique ne sont que des estimations.

International audience; Increasingly large ensembles of GCM simulations are becoming available for climate change impact studies, through multi-model and multi-run ensembles or perturbed physics ensembles. Moreover, advances in statistical downscaling make it now possible to downscale such large ensembles to the spatial resolution relevant for impact models. Additionally, many downscaling methods are themselves stochastic, which may again increase the size of downscaled projections ensembles. The computational cost of processing such large ensembles through impact models like physically-based distributed hydrological models may however be prohibitive. If recommandations for selecting GCM simulations from large ensembles have been recently proposed, there are still numerous open questions on how to adequately sample downscaled ensembles of such simulations. This work proposes a sub-sampling approach undertaken for providing a set of downscaled projections over the Durance catchment (southern French Alps) for building informed adaptation scenarios in water resource management. 30 transient runs from the ENSEMBLES Stream2 GCMs under the A1B emissions scenario have been downscaled over the Durance catchment by three variants of the K-nearest neighbours resampling approach: an analog method, a weather type method and a regression-based method (Lafaysse et al., 2013). 100 downscaled realizations have been stochastically generated by each method for all GCM runs (1 to 6 runs from 4 different GCMs). The approach selected here aims at preserving the relative contributions of the four different sources of uncertainties considered, namely (1) GCM structure, (2) large-scale natural variability, (3) structure of the downscaling method, and (4) catchment-scale natural variability. Given the relatively low sample size of the first three sources, this approach focused on sub-sampling 10 realizations of each downscaling method by applying a conditioned Latin Hypercube Sampling (see e.g., Christierson et al., 2012) and therefore preserving the statistical distribution of the 100 realizations. Many open choices---nature of the conditioning variables (future values/changes), associated temporal and spatial scales---have been carefully made by assessing their relevance for water resource management. The effect of conditioning the sampling on climate responses in temporally and spatially integrated variables---changes in catchment-scale winter/summer and interannual mean precipitation and temperature between two time slices---has been validated by assessing the response in more extreme independent variables like changes in the annual precipitation with an exceedance probability of 0.8 and in maximum consecutive dry days. A transient analysis of variance moreover confirmed the effectiveness of the approach in preserving the relative contribution of uncertainty sources for various climate variables. Critically, this approach allows to propagate the sources of uncertainty through impact models while reducing the associated computational burden. However, in order to meet actual constraints of the impact community, there is an urgent need for producing guidelines for sub-sampling multi-level ensembles of downscaled climate projections, i.e. 3D arrays of combinations in emissions scenarios, GCMs and downscaling methods.

International audience; Dans son adaptation du roman de Boulgakov, la compagnie Complicite a choisi de jouer sur toutes les surfaces de la Cour d'honneur du Palais de papes, en encadrant le plateau par de vastes projections. Certaines sont explicatives, comme ces vues aériennes de Moscou ou de Yalta qui aident le spectateur à s’orienter dans l’enchaînement rapide des scènes et les déplacements parfois magiques des personnages ; d’autres posent un décor à l’aide de grands paysages ou d’images d’archives qui font revivre des foules moscovites dans la nuit avignonnaise. Bien souvent, les images sont captées directement sur le plateau, magnifiant pour le public les corps passionnés d’un Ponce Pilate migraineux, du Christ qu’il cherche à sauver, du Maître qui raconte leur histoire et de son amante Marguerite. Mais, si la caméra permet ainsi de construire une verticalité parfois vertigineuse, le rapport qu’elle installe entre ces gigantesques projections et les corps des acteurs ne se réduit pas au gros plan ni au cadre fictionnel. Car la taille humaine – celle des comédiens qui évoluent dans des espaces restreints, confinés, souvent dessinés par des lignes géométriques sur le plateau – y est mise en tension avec les grandes images, qu’il s’agisse de celles du mythe chrétien ou de l’histoire soviétique. Vacillant entre l’image grandiose et le monumentalisme oppressant, ce jeu d’échelles permet de donner une dimension visuelle aux problématiques narratives explorées par Boulgakov, tout en satisfaisant le désir d’infini qui parcourt les spectacles de McBurney.

International audience; A deterministic automaton accepting a regular language L is a state-partition automaton with respect to a projection P if the state set of the deterministic automaton accepting the projected language P(L), obtained by the standard subset construction, forms a partition of the state set of the automaton. In this paper, we study fundamental properties of state-partition automata. We provide a construction of the minimal state-partition automaton for a regular language and a projection, discuss closure properties of state-partition automata under the standard constructions of deterministic automata for regular operations, and show that almost all of them fail to preserve the property of being a state-partition automaton. Finally, we define the notion of a state-partition complexity, and prove the tight bound on the state-partition complexity of regular languages represented by incomplete deterministic automata.

ISI Document Delivery No.: 059IA Times Cited: 10 Cited Reference Count: 29 Cited References: BROECKER WS, 1975, SCIENCE, V189, P460, DOI 10.1126/science.189.4201.460 Chao BF, 2008, SCIENCE, V320, P212, DOI 10.1126/science.1154580 Church JA, 2011, SURV GEOPHYS, V32, P585, DOI 10.1007/s10712-011-9119-1 CSIRO, 2012, IPCC AR4 SEA LEV PRO Foster G, 2011, ENVIRON RES LETT, V6, DOI 10.1088/1748-9326/6/4/044022 Grinsted A, 2010, CLIM DYNAM, V34, P461, DOI 10.1007/s00382-008-0507-2 HANSEN J, 1981, SCIENCE, V213, P957, DOI 10.1126/science.213.4511.957 Hegerl GC, 2007, CLIMATE CHANGE 2007: THE PHYSICAL SCIENCE BASIS, P663 Houghton J. T., 2001, CLIMATE CHANGE 2001 Kemp AC, 2011, P NATL ACAD SCI USA, V108, P11017, DOI 10.1073/pnas.1015619108 Konikow LF, 2011, GEOPHYS RES LETT, V38, P5 Lean JL, 2009, GEOPHYS RES LETT, V36, DOI 10.1029/2009GL038932 Lean JL, 2008, GEOPHYS RES LETT, V35, DOI 10.1029/2008GL034864 Lettenmaier DP, 2009, NAT GEOSCI, V2, P452, DOI 10.1038/ngeo567 Llovel W, 2011, GLOBAL PLANET CHANGE, V75, P76, DOI 10.1016/j.gloplacha.2010.10.008 Vermeer M, 2009, P NATL ACAD SCI USA, V106, P21527, DOI 10.1073/pnas.0907765106 Meehl GA, 2007, CLIMATE CHANGE 2007: THE PHYSICAL SCIENCE BASIS, P747 Moore J. C., 2005, EOS T AGU, V86, P226, DOI DOI 10.1029/2005EO240003 Morice CP, 2012, J GEOPHYS RES-ATMOS, V117, DOI 10.1029/2011JD017187 NOAA, 2012, CO2 DAT US NAT OC AT Rahmstorf S, 2010, HAPPY BIRTHDAY GLOBA Rahmstorf S, 2007, SCIENCE, V315, P368, DOI 10.1126/science.1135456 Rahmstorf S, 2012, CLIM DYNAM, V39, P861, DOI 10.1007/s00382-011-1226-7 Rahmstorf S, 2007, SCIENCE, V316, P709, DOI 10.1126/science.1136843 Rignot E, 2011, GEOPHYS RES LETT, V38, DOI 10.1029/2011GL046583 Schmidt GA, 2012, 2011 UPDATES MODEL D Schonwiese CD, 2010, METEOROL Z, V19, P3, DOI 10.1127/0941-2948/2010/0421 Solomon S, 2007, CLIMATE CHANGE 2007: THE PHYSICAL SCIENCE BASIS, P19 Van den Broeke MR, 2011, SURV GEOPHYS, V32, P495, DOI 10.1007/s10712-011-9137-z Rahmstorf, Stefan Foster, Grant Cazenave, Anny Rahmstorf, Stefan/A-8465-2010 Rahmstorf, Stefan/0000-0001-6786-7723 10 IOP PUBLISHING LTD BRISTOL ENVIRON RES LETT; We analyse global temperature and sea-level data for the past few decades and compare them to projections published in the third and fourth assessment reports of the Intergovernmental Panel on Climate Change (IPCC). The results show that global temperature continues to increase in good agreement with the best estimates of the IPCC, especially if we account for the effects of short-term variability due to the El Nino/Southern Oscillation, volcanic activity and solar variability. The rate of sea-level rise of the past few decades, on the other hand, is greater than projected by the IPCC models. This suggests that IPCC sea-level projections for the future may also be biased low.

Classical mathematics is neither homogeneous nor all of one piece. Some chapters in its development go back as far as Greek mathematics. We have only to think, for example, of plane geometry, the geometry of cones or the geometry of spheres. Others are rooted in Arab mathematics, embracing the algebraic disciplines and work on geometrical transformations. Finally, yet other developments, such as infinitesimal calculus took place in Europe in the seventeenth century. What we can say without fear of contradiction, however, is that the distinctive characteristic of this classical mathematics is that it is ‘algebraic and analytical’. The question that remains is precisely when and how this distinctive characteristic saw the light of day, that is, how this algebraic-analytical reasoning arose and how it developed.

Introduction Deterministic single-tree models are commonly used in forestry. However, there is evidence that stochastic events may interact with the nonlinear mechanisms that underlie forest growth. As a consequence, stochastic and deterministic simulations could yield different results for the same single-tree model and the same initial conditions. This hypothesis was tested in this study. Material and methods We used a single-tree growth model that can be implemented either stochastically or deterministically. Two data sets of 186 and 342 plots each were used for the comparisons. For each plot, the simulations were run on a 100-year period using 10-year growth steps. Three different response variables were compared. Results The results showed that there were differences between the predictions from stochastic and deterministic simulations for some response variables and that randomness alone could not explain these differences. In the case of deterministic simulations, the fact that predictions are reinserted into the model at each growth step is a concern. These predictions are actually random variables and their transformations may result in biased quantities. Forest growth modellers should be aware that deterministic simulations may not correspond to the mathematical expectation of the natural dynamics.

This paper focuses on unsupervised curve classification in the context of nuclear industry. At the Commissariat à l'Energie Atomique (CEA), Cadarache (France), the thermal-hydraulic computer code CATHARE is used to study the reliability of reactor vessels. The code inputs are physical parameters and the outputs are time evolution curves of a few other physical quantities. As the CATHARE code is quite complex and CPU-time consuming, it has to be approximated by a regression model. This regression process involves a clustering step. In the present paper, CATHARE output curves are clustered using a k-means scheme, with a projection onto a lower dimensional space. We study the properties of the empirically optimal cluster centers found by the clustering method based on projections, compared to the “true” ones. The choice of the projection basis is discussed, and an algorithm is implemented to select the best projection basis among a library of orthonormal bases. The approach is illustrated on a simulated example and then applied to the industrial problem.