9 research outputs found
Suivi spatiotemporel de l’érosivité des pluies au Maroc à l’aide des données satellitaires libres
This study aims particularly to overcome the lack of rainfall measurements and to demonstrate the usefulness of open satellite data rainfall-erosivity estimation in Morocco. For this purpose, a short time series of two satellite products, namely CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) and TRMM (Tropical Rainfall Measuring Mission). were used and correlated to in-situ measurements of a period of 17 years (2000- 2016). This analysis revealed a relatively better correlation between monthly CHIRPS product and in-situ measurements. the coefficient of determination is arround 0.81. After its calibration using regression equations, this product were used to estimate the rainfall-erosivity over Morocco according to Renard and Freimund equation. The result showed a geographical disparity and an annually weak evolution of erosivity. Likewise, the study pointed out a significant difference in the estimated erosivity across seasons. This imply a reduction of 3% in summer and 15% in spring and a remarkable increase of 33% in autumn and 39% in winter. The prominent change of the seasonality of rainfall erosivity is very significant in the course of agricultural practices’ evolution and the adoption of adequate measures of soil protection.
Keywords: Erosion, erosivity, rainfall, modelling, CHIRPS, TRMM, MoroccoLa présente étude a pour objectif principal de répondre à un besoin pressant des données pluviométriques à l’aide des données satellitaires libres et par conséquent, faciliter les prises de décision pour les gestionnaires des ressources naturelles. Par le biais des séries chronologiques couvrant la période 2000 - 2016, le suivi spatiotemporel de l’érosivité des pluies a été étudié. Les produits satellitaires CHIRPS (Climate Hazards Group InfraRed Precipitation with Station data) et TRMM (Tropical Rainfall Measuring Mission) ont été choisis pour suivre l’évolution de l’érosivité des pluies. Les études de corrélations effectuées entre les données satellitaires et les données pluviométriques mesurées ont montré que les données CHIRPS sont les mieux corrélées. La validation de ces résultats a donné un coefficient de détermination de 0,81. Les données retenues ont été ensuite calibrées avec une équation de régression. Le choix de la formule de Renard et Freimund comme modèle de calcul du facteur d’érosivité a montré une forte disparité géographique et une faible évolution de l’érosivité à l’échelle annuelle. De même, elle fait ressortir une très forte évolution de celle-ci selon les saisons avec une diminution de 3% en été et de 24% au printemps et une augmentation marquée de celle-ci pendant l’automne (33%) et l’hiver (39%). Le changement prononcé de la saisonnalité de l’érosivité des pluies est très déterminant dans l’orientation de l’évolution des pratiques agricoles et le choix des mesures adéquates de protection des sols.
Mots-clés : érosion, érosivité, précipitation, modélisation, CHIRPS, TRMM, Maro
Impact Du Changement Climatique Sur L’évolution De L'érosivité Des Pluies Dans Le Rif Occidental (Nord Du Maroc)
The rainfall erosivity factor (R factor in Universal Soil Loss Equation), denoting rain energy, is a key factor for soil loss modeling. Its present and future estimation is thus significant for any action related to soil and water conservation and planning. The extended series of precipitations at high temporal resolution, essential to its evaluation, are not readily available in Morocco. The objective of this study is to predict the evolution of rainfall erosivity by 2080 in the Western Rif, based on predictions of daily rain provided by the General Climatic Models (GCMs). To reflect the seasonal variability of rainfall, and thus of R factor, a series of instantaneous rain measured over 35 consecutive years was used to monthly calibrate a model to calculate erosivity based of daily rainfall. The application of this model to the predictions of different GCMs and for various scenarios of climate evolution in Western Rif shows a weak evolution of erosivity on an annual timescale but a very strong evolution of the latter according to seasons with a reduction in R factor during winter and spring, and a pronounced increase during summer and autumn. This discernable change of the seasonality of rainfall erosivity is very useful for adjusting the evolution of agricultural practices and for selecting appropriate soil protection measures
Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection
Cervical artery dissection (CeAD), a mural hematoma in a carotid or vertebral artery, is a major cause of ischemic stroke in young adults although relatively uncommon in the general population (incidence of 2.6/100,000 per year). Minor cervical traumas, infection, migraine and hypertension are putative risk factors, and inverse associations with obesity and hypercholesterolemia are described. No confirmed genetic susceptibility factors have been identified using candidate gene approaches. We performed genome-wide association studies (GWAS) in 1,393 CeAD cases and 14,416 controls. The rs9349379[G] allele (PHACTR1) was associated with lower CeAD risk (odds ratio (OR) = 0.75, 95% confidence interval (CI) = 0.69-0.82; P = 4.46 × 10(-10)), with confirmation in independent follow-up samples (659 CeAD cases and 2,648 controls; P = 3.91 × 10(-3); combined P = 1.00 × 10(-11)). The rs9349379[G] allele was previously shown to be associated with lower risk of migraine and increased risk of myocardial infarction. Deciphering the mechanisms underlying this pleiotropy might provide important information on the biological underpinnings of these disabling conditions
Analysis of the hydro-sedimentary functioning of a watershed of the Western Rif of Morocco using the SWAT model: Case of the Tleta watershed
Le modèle SWAT (Soil and Water Assessment Tool) est un outil de simulation des flux dans le paysage, très utile pour orienter la gestion et les aménagements des bassins versants. Dans cette optique, ce modèle a été testé pour reproduire, à un pas de temps journalier, les flux d’eau et de sédiments arrivant à la retenue du barrage Ibn Batouta pour la période 1980-2010. Diverses données climatiques (précipitation et température), morphologiques (MNT) et thématiques (occupation du sol et pédologie) ont été utilisées pour l’alimentation du modèle. Les mesures acquises au niveau de la retenue Ibn Batouta sur les périodes 1980-1982, 1983-1996 et 1997-2010 ont été utilisées respectivement pour les étapes d’initialisation, de calibration et de validation après avoir exécuté une analyse de sensibilité pour déterminer les paramètres les plus sensibles. Les indices de performance R², NSE et PBIAS ont été adoptés pour évaluer et contrôler la qualité des prédictions des débits mensuels liquides et solides. En effet la performance de prédiction est très élevée pour les débits liquides mensuels avec R² (0,95; 0,90), NSE (0,94; 0,89) et PBIAS (-6; 2) respectivement pour la période de calibration et la période de validation. La performance des prédictions des transports solides mensuels est également très satisfaisante avec R² (0,83; 0,64), NSE (0,82; 0,61) et PBIAS (17; -6). Au final, le modèle SWAT permet de reproduire correctement les flux mensuels d’eau et de sédiments à l’exutoire du bassin versant Tleta et son utilisation pour tester des scénarios de gestion et d’aménagements, peut donc être envisagée.
Mots clefs: SWAT, Modélisation hydrologique, Érosion hydrique, Rif Occidental, MarocSWAT Model (Soil and Water Assessment Tool) is a tool for simulating flows in the landscape, usefulfor guiding management and ground works within catchment areas. Accordingly, this model was tested to reproduce, on a daily times pan, water and sediment flows arriving to Ibn Batouta reservoir over the period 1980-2010. Various climatic (precipitation and temperature), morphologic (MNT) and thematic data (land use and pedology) were used for feeding the model. The measurements acquired at Ibn Batouta reservoir during the periods 1980-1982, 1983-1996 and 1997-2010 were used respectively for initialization, calibration and validation after running the sensitivity analysis to determine the most significant parameters. The performances indices of R², NSE and PBIAS were adopted to assess and control the quality of predictions of the monthly flows of water and sediments. The performance of prediction of monthly water flows is very high with R² (0.95; 0.90), NSE (0.94; 0.89) and PBIAS (-6; 2) respectively for both periods of calibration and validation. Meanwhile the performance of predictions of the monthly solid transport is very satisfactory with R² (0.83; 0.64), NSE (0.82; 0.61) and PBIAS (17; -6) respectively. Finally, SWAT model allows to properly reproducing monthly water and sediment flows within the Tleta catchment area and testing scenarios of management and ground works to be considered.
Key words: SWAT, hydrological modeling, water erosion, Western Rif, Morocc
DriveToGaether: a Turnkey Collaborative Robotic Event Platform
International audienceThis paper reports the organization of an event that enabled experts as well as non-specialists to practice Artificial Intelligence on robots, with the goal to enforce human-AI cooperation. The end aim of this paper is to make the material and virtual platform built for the event reusable by as many people as possible, so that the event can be reproduced and can give rise to new discoveries or to the production of new data sets and benchmarks. The underlying purpose is to de-demonize AI and to foster group work around a fun, rewarding and caring project.
Epidemiology, pathophysiology, diagnosis, and management of intracranial artery dissection
Common variation in PHACTR1 is associated with susceptibility to cervical artery dissection
Rare predicted loss-of-function variants of type I IFN immunity genes are associated with life-threatening COVID-19
BackgroundWe previously reported that impaired type I IFN activity, due to inborn errors of TLR3- and TLR7-dependent type I interferon (IFN) immunity or to autoantibodies against type I IFN, account for 15-20% of cases of life-threatening COVID-19 in unvaccinated patients. Therefore, the determinants of life-threatening COVID-19 remain to be identified in similar to 80% of cases.MethodsWe report here a genome-wide rare variant burden association analysis in 3269 unvaccinated patients with life-threatening COVID-19, and 1373 unvaccinated SARS-CoV-2-infected individuals without pneumonia. Among the 928 patients tested for autoantibodies against type I IFN, a quarter (234) were positive and were excluded.ResultsNo gene reached genome-wide significance. Under a recessive model, the most significant gene with at-risk variants was TLR7, with an OR of 27.68 (95%CI 1.5-528.7, P=1.1x10(-4)) for biochemically loss-of-function (bLOF) variants. We replicated the enrichment in rare predicted LOF (pLOF) variants at 13 influenza susceptibility loci involved in TLR3-dependent type I IFN immunity (OR=3.70[95%CI 1.3-8.2], P=2.1x10(-4)). This enrichment was further strengthened by (1) adding the recently reported TYK2 and TLR7 COVID-19 loci, particularly under a recessive model (OR=19.65[95%CI 2.1-2635.4], P=3.4x10(-3)), and (2) considering as pLOF branchpoint variants with potentially strong impacts on splicing among the 15 loci (OR=4.40[9%CI 2.3-8.4], P=7.7x10(-8)). Finally, the patients with pLOF/bLOF variants at these 15 loci were significantly younger (mean age [SD]=43.3 [20.3] years) than the other patients (56.0 [17.3] years; P=1.68x10(-5)).ConclusionsRare variants of TLR3- and TLR7-dependent type I IFN immunity genes can underlie life-threatening COVID-19, particularly with recessive inheritance, in patients under 60 years old