Assessing the role of riparian vegetation and land use on river ecological status using remote sensing and spatial modelling

International audiencePreserving or restoring the ecological quality of aquatic ecosystems is a major objective of Water Framework Directive. A pending question deals with the gain in river ecological status indicators that could be allowed by restoring riparian tree vegetation. In order to quantify in a statistically relevant way the role of riparian vegetation on river ecosystems, a regional approach is required that mobilizes three complementary fields of research : (1) the use of very high spatial resolution satellite imagery to map river corridor land use and riparian vegetation along large river networks ; (2) the design and quantification of synthetic spatialized indicators of river corridor land use; (3) the development of pressures/state spatialized models that quantify the relation between river corridor land use indicators and river water bodies ecological status indicators. The corresponding methods were developed and implemented on various river basins, particularly over lower Normandy river networks (6000 km long; 157 ecological stations). Results show for instance that in this region, changing the local land use along a river from agriculture to forest (over a buffer 1km long and 30m large on both sides of the river) allows in average to increase by 0.3 points the river ecological status indicators (EQR-IBGN between 0 and 1). Such results are of high interest for decision-makers that can estimate the interest of investing in restoration strategies by anticipating their effect in terms of Water Framework Directive standards

Proposition d’une approche multidisciplinaire pour la maintenance prédictive des chaussées

La dégradation d’une chaussée a pour origine de multiples facteurs tels que le trafic, les conditions climatiques et ses caractéristiques structurelles. Pour maintenir la qualité des infrastructures routières et prolonger leurs durées de vie tout en réduisant les coûts de maintenance, il devient essentiel de prédire et d'anticiper ces dégradations. Dans cette optique, l’utilisation de la maintenance prédictive, basée sur des moyens de surveillance in-situ, d'analyse statistique et d'intelligence artificielle, est donc nécessaire. Cependant, sa mise en œuvre fait face à de nombreux défis tels que la gestion de grandes quantités de données collectées par diverses sources mais aussi la modélisation dans un environnement incertain. Dans ce contexte, pour améliorer la surveillance des infrastructures routières, cette étude combine trois disciplines scientifiques pour démontrer la faisabilité d’un jumeau numérique d'une section de chaussée. La méthodologie proposée s’appuie sur l'optimisation des moyens d'instrumentation des routes, à l'aide de capteurs sans fil, pour alimenter des modèles mécaniques et issus des données destinés à prédire l'endommagement de la chaussée et ainsi anticiper son état de santé. Cette approche pluridisciplinaire est mise en œuvre sur un cas d'étude : une section d’autoroute instrumentée dans la région de Bordeaux en France.The pavement deterioration can be caused by multiple factors such as traffic, weather conditions and structural characteristics. To maintain the quality of roads and extend their life while reducing maintenance costs, it is essential to predict and anticipate deterioration. The use of predictive maintenance, based on in-situ monitoring, statistical analysis and artificial intelligence, is therefore necessary. Nevertheless, its implementation must deal with several challenges such as managing large amounts of data collected from different sources or modelling in an uncertain environment. In this context, to improve road infrastructure monitoring, this study combines three scientific fields to demonstrate the feasibility of a digital twin of a pavement section. The proposed methodology is based on the optimization of road instrumentation tools, using wireless sensors, to feed mechanical and data-driven models to predict pavement damage and thus anticipate its health. This multidisciplinary approach is implemented on a case study: an instrumented highway section in the Bordeaux region in France

Exploring the use of a participative design in the early development of a predictive test : the importance of physician involvement

In this study, we contribute to the personalized medicine and health care management literature by developing and testing a new participative design approach. We propose that involving gastroenterologists in the development of a predictive test to assist them in their clinical decision-making process for the treatment of inflammatory bowel diseases will increase the likelihood of their acceptance of the innovation. Based on data obtained from 6 focus groups across Canada from a total of 28 physicians, analyses reveal that current tools do not enable discriminating between treatment options to find the best fit for each patient. Physicians expect a new predictive tool to have the capability of showing clear reliability and significant benefits for the patient, while being accessible in a timely manner that facilitates clinical decisions. Physicians also insist on their key role in the implementation process, hence confirming the relevance and importance of participative designs in personalized medicine

Direct sediment transfer from land to deep-sea: Insights into shallow multibeam bathymetry at La Réunion Island

International audienceSubmarine canyon heads are key areas for understanding the triggering factors of gravity currents responsible for the transfer of detrital sediment to the deep basins. This contribution offers a detailed picture of canyon heads off La Réunion Island, with high-resolution multibeam bathymetry in the water depth range of 4-220 m. The present feeding of the Cilaos turbidite system, one of the largest modern volcaniclastic systems in the world, is deduced from morphological and sedimentological interpretations of newly acquired data. The study highlights small-scale sedimentary features indicating hydrodynamic and sedimentary processes. A direct connexion between the Saint-Etienne river mouth and submarine canyons is evidenced by the complete incision of the shelf and the presence of canyon heads connected to the modern deltaic bar. This direct connection, supplied by river torrential floods (cyclonic floods every two or three years), suggests the continuity of high-density fluvial flows to submarine gravity flows, forming hyperpycnal flows in the canyon. The initiation of secondary submarine gravity flows by storm waves (large austral waves and cyclonic waves) is also proposed for submarine canyons with large canyon heads developed in the surf zone from a sandy coastal bar. Bedforms in active canyon axis are considered as an indicator of the frequent activity of high-density turbidity currents. Moreover, a morphological record of last glacial and deglacial sea level variations is preserved, and particularly the Last Glacial Maximum sea level with the presence of small vertical cliffs, observed in this bathymetric data, which likely corresponds to a paleo-shoreline or paleo-reefs

Morphological, structural, optical, and electrical study of nanostructured thin films: Charge transport mechanism of p-type Co3O4

Morphological, structural, optical, and electrical study of nanostructured thin films: Charge transport mechanism of p-type Co3O

Epilepsy with migrating focal seizures

To report new sporadic cases and 1 family with epilepsy of infancy with migrating focal seizures (EIMFSs) due to KCNT1 gain-of-function and to assess therapies' efficacy including quinidine. We reviewed the clinical, EEG, and molecular data of 17 new patients with EIMFS and KCNT1 mutations, in collaboration with the network of the French reference center for rare epilepsies. The mean seizure onset age was 1 month (range: 1 hour to 4 months), and all children had focal motor seizures with autonomic signs and migrating ictal pattern on EEG. Three children also had infantile spasms and hypsarrhythmia. The identified KCNT1 variants clustered as "hot spots" on the C-terminal domain, and all mutations occurred de novo except the p.R398Q mutation inherited from the father with nocturnal frontal lobe epilepsy, present in 2 paternal uncles, one being asymptomatic and the other with single tonic-clonic seizure. In 1 patient with EIMFS, we identified the p.R1106Q mutation associated with Brugada syndrome and saw no abnormality in cardiac rhythm. Quinidine was well tolerated when administered to 2 and 4-year-old patients but did not reduce seizure frequency. The majority of the KCNT1 mutations appear to cluster in hot spots essential for the channel activity. A same mutation can be linked to a spectrum of conditions ranging from EMFSI to asymptomatic carrier, even in the same family. None of the antiepileptic therapies displayed clinical efficacy, including quinidine in 2 patients

In- and out-plane transport properties of chemical vapor deposited TiO2 anatase films

Due to their polymorphism, TiO2 films are quintessential components of state-of-the-art functional materials and devices for various applications from dynamic random access memory to solar water splitting. However, contrary to other semiconductors/dielectric materials, the relationship between structural/morphological and electrical properties at the nano and microscales remains unclear. In this context, the morphological characteristics of TiO2 films obtained by metal–organic chemical vapor deposition (MOCVD) and plasma-enhanced chemical vapor deposition (PECVD), the latter including nitrogen doping, are investigated and they are linked to their in- and out-plane electrical properties. A transition from dense to tree-like columnar morphology is observed for the MOCVD films with increasing deposition temperature. It results in the decrease in grain size and the increase in porosity and disorder, and subsequently, it leads to the decrease in lateral carrier mobility. The increase in nitrogen amount in the PECVD films enhances the disorder in their pillar-like columnar morphology along with a slight increase in density. A similar behavior is observed for the out-plane current between the low temperature MOCVD films and the undoped PECVD ones. The pillar-like structure of the latter presents a lower in-plane resistivity than the low temperature MOCVD films, whereas the out-plane resistivity is lower. The tree-like columnar structure exhibits poor in- and out-plane conductivity properties, whereas pillar-like and dense TiO2 exhibits similar in- and out-plane conductivities even if their morphologies are noticeably different

Non-alcoholic fatty liver disease, and the underlying altered fatty acid metabolism, reveals brain hypoperfusion and contributes to the cognitive decline in APP/PS1 mice

Non-alcoholic fatty liver disease (NAFLD), the leading cause of chronic liver disease, is associated with cognitive decline in middle-aged adults, but the mechanisms underlying this association are not clear. We hypothesized that NAFLD would unveil the appearance of brain hypoperfusion in association with altered plasma and brain lipid metabolism. To test our hypothesis, amyloid precursor protein/presenilin-1 (APP/PS1) transgenic mice were fed a standard diet or a high-fat, cholesterol and cholate diet, inducing NAFLD without obesity and hyperglycemia. The diet-induced NAFLD disturbed monounsaturated and polyunsaturated fatty acid (MUFAs, PUFAs) metabolism in the plasma, liver, and brain, and particularly reduced n-3 PUFAs levels. These alterations in lipid homeostasis were associated in the brain with an increased expression of Tnfalpha, Cox2, p21, and Nox2, reminiscent of brain inflammation, senescence, and oxidative stress. In addition, compared to wild-type (WT) mice, while brain perfusion was similar in APP/PS1 mice fed with a chow diet, NAFLD in APP/PS1 mice reveals cerebral hypoperfusion and furthered cognitive decline. NAFLD reduced plasma beta40- and beta42-amyloid levels and altered hepatic but not brain expression of genes involved in beta-amyloid peptide production and clearance. Altogether, our results suggest that in a mouse model of Alzheimer disease (AD) diet-induced NAFLD contributes to the development and progression of brain abnormalities through unbalanced brain MUFAs and PUFAs metabolism and cerebral hypoperfusion, irrespective of brain amyloid pathology that may ultimately contribute to the pathogenesis of AD