New Jurassic amber outcrops from Lebanon

International audienceAmber predating the Lower Cretaceous is extremely rare. During the past two decades, records of discoveries of amber sites have increased considerably worldwide. We report herein the discovery of ten new outcrops of amber from the Late Jurassic in Lebanon, in addition to other nine outcrops described by Azar et al. (2010). Some of these outcrops gave large centimetric sized amber pieces. Each of these new amber outcrops is described, and its infrared spectrum is given. Though the Jurassic amber yielded to date no more than some fungal inclusions, this discovery is significant and promising especially in the reconstruction of the paleoenvironment

Suivi de la qualité bactériologique des eaux de surface (rivière Nahr Ibrahim, Liban)

Le bassin versant du Narh Ibrahim est classé parmi les sites du patrimoine mondial. Les rejets sauvages solides et liquides ont un impact important sur le développement d’une contamination bactériologique tout au long de la rivière. Dans cette étude, des paramètres physico-chimiques et bactériologiques ont été suivis sur neuf sites de prélèvement qui couvrent la rivière Nahr Ibrahim de son amont jusqu’à son estuaire. L’ensemble des paramètres est étudié pendant des périodes de l’année caractérisées par un temps sec ou un temps de crue. Au cours de ces périodes, ces paramètres ont révélé une influence importante du type d’occupation des sols et des phénomènes de lessivage sur la composition bactériologique de la rivière. L’origine et le degré de la contamination bactérienne instantanée ont été également identifiés. Une approche statistique multivariée a montré que l’effet de la localisation du site masque l’effet date sur un même site et pendant la même période. Les sites en aval de la rivière sont caractérisés par une pollution en nitrate et une contamination bactériologique alors que les sites en amont sont marqués par une contamination bactériologique seulement.The Nahr Ibrahim catchment area is classified as an international heritage site. Along the Nahr Ibrahim River, solid and liquid effluents have an important impact on bacterial contamination. Physico-chemical and bacteriological parameters were studied at nine sampling sites located along the Nahr Ibrahim River from its source to its estuary. Total bacteria, total coliforms, fecal coliforms and fecal streptococci were studied during dry and wet weather periods. During these periods, the studied parameters revealed an important influence of the type of soil and leaching on the bacteriological composition of the river. Furthermore, the origin and the degree of temporary bacteriological contamination were identified. A multivariate statistical approach demonstrated that the effect of site location masked the effect of sampling date on the degree of bacteriological contamination. Downstream river sites were characterized by nitrate and bacterial pollution whereas upstream sites showed only by bacterial contamination

Restauration aveugle adaptative pour images monochromes et hyperspectrales

Image restoration presents a significant challenge when regularization parameter values, PSF, and other a priori knowledge are not available. The objective of this thesis is to develop an easily applicable restoration method by eliminating the necessity for prior information and empirical parameter tuning. To achieve this objective, we have developed an adaptive blind image restoration method that operates without requiring prior information. This method can be applied to restore monochrome, multispectral, and hyperspectral images, while optimizing restoration results without the need for empirical parameter tuning. The superiority of our proposed adaptive blind restoration method is demonstrated through evaluations on diverse image databases, outperforming eleven existing non-neural network and supervised/semi-supervised neural network methods from the state-of-the-art. In conclusion, the proposed method can be easily applied to restore degraded images due to its blind nature.La restauration d'images représente un défi important lorsque les valeurs des paramètres de régularisation, la PSF et d'autres connaissances a priori ne sont pas disponibles. L'objectif de cette thèse est de développer une méthode de restauration facilement applicable en éliminant la nécessité d'informations préalables et d'un réglage empirique des paramètres. Pour atteindre cet objectif, nous avons développé une méthode adaptative de restauration d'images aveugle qui fonctionne sans nécessiter d'informations a priori. Cette méthode peut être appliquée pour restaurer des images monochromes, multispectrales et hyperspectrales, tout en optimisant les résultats de traitement sans nécessiter de réglage empirique des paramètres de régularisation. La supériorité de notre méthode de restauration aveugle adaptative est démontrée grâce à des évaluations sur diverses bases de données d'images, surpassant onze méthodes non-neuronales et neuronales supervisées/ semi-supervisées de l'état de l'art. En conclusion, la méthode proposée peut être facilement appliquée pour restaurer des images dégradées en raison de sa nature aveugle

Restauration aveugle adaptative pour images monochromes et hyperspectrales

Image restoration presents a significant challenge when regularization parameter values, PSF, and other a priori knowledge are not available. The objective of this thesis is to develop an easily applicable restoration method by eliminating the necessity for prior information and empirical parameter tuning. To achieve this objective, we have developed an adaptive blind image restoration method that operates without requiring prior information. This method can be applied to restore monochrome, multispectral, and hyperspectral images, while optimizing restoration results without the need for empirical parameter tuning. The superiority of our proposed adaptive blind restoration method is demonstrated through evaluations on diverse image databases, outperforming eleven existing non-neural network and supervised/semi-supervised neural network methods from the state-of-the-art. In conclusion, the proposed method can be easily applied to restore degraded images due to its blind nature.La restauration d'images représente un défi important lorsque les valeurs des paramètres de régularisation, la PSF et d'autres connaissances a priori ne sont pas disponibles. L'objectif de cette thèse est de développer une méthode de restauration facilement applicable en éliminant la nécessité d'informations préalables et d'un réglage empirique des paramètres. Pour atteindre cet objectif, nous avons développé une méthode adaptative de restauration d'images aveugle qui fonctionne sans nécessiter d'informations a priori. Cette méthode peut être appliquée pour restaurer des images monochromes, multispectrales et hyperspectrales, tout en optimisant les résultats de traitement sans nécessiter de réglage empirique des paramètres de régularisation. La supériorité de notre méthode de restauration aveugle adaptative est démontrée grâce à des évaluations sur diverses bases de données d'images, surpassant onze méthodes non-neuronales et neuronales supervisées/ semi-supervisées de l'état de l'art. En conclusion, la méthode proposée peut être facilement appliquée pour restaurer des images dégradées en raison de sa nature aveugle

Blind Hyperspectral Image Restoration

International audienceA new blind restoration method for hyperspectral images is proposed in this paper. This method eliminates prior known information and avoids empirical tuning of the regularization parameters. It involves two major steps: the first step is an unsupervised partitioning using affinity propagation to blindly select spectral components and instead of estimating the PSF using all spectral components, we use only the exemplar component of each correlated group. The second step involves restoration of the hyperspectral image using the appropriate estimated PSF for each group. A multi-scale pyramidal model is used to estimate the PSF and the latent image on each selected spectral component. Hyperspectral images are used to assess the proposed method. Three objective criteria are adopted the mean of PSNR, SSIM, and L1-norm of the estimation error

Chemical coagulation of combined sewer overflow: Heavy metal removal and treatment optimization

International audienceThe coagulation of combined sewer overflow (CSO) was investigated by jar-testing with two commercial coagulants, a ferric chloride solution (CLARFER) and a polyaluminium chloride (WAC HB). CSO samples were collected as a function of time during various wet-weather events from the inlet of Boudonville retention basin, Nancy, France. Jar-tests showed that an efficient turbidity removal can be achieved with both coagulants, though lower optimum dosages and higher re-stabilization concentrations were obtained with the aluminum-based coagulant. Optimum turbidity removal also yielded effective heavy metal elimination. However, the evolution with coagulant dosage of Cu, Zn, Pb, Cr, soluble and suspended solids contents followed various patterns. The removal behaviors can be explained by a selective aggregation of heavy metal carriers present in CSO and a specific interaction between hydrolyzed coagulant species and soluble metals. Stoichiometric relationships were established between optimal coagulant concentration, range of optimal dosing, and CSO conductivity, thus providing useful guidelines to adjust the coagulant demand during the course of CSO events

Lead bioaccumulation in Opuntia ficus-indica following foliar or root exposure to lead-bearing apatite

International audienceThe contamination of edible leafy vegetables by atmospheric heavy metal-bearing particles is a major issue in environmental toxicology. In this study, the uptake of lead by cladodes of Opuntia ficus-indica (Ofi), traditionally used in Mexican cuisine and in livestock fodder, is investigated after a 4-months exposure of either cladodes or roots to synthetic Pb-fluorapatite particles. Atomic Absorption Spectroscopy (AAS) for the quantitative analysis of Pb levels, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy (SEM-EDX) for the examination of the cladode surface and fate of particles, and Micro-X-ray fluorescence (μXRF) measurements for elemental mapping of Pb in cladodes, were used. The results evidence that foliar contamination may be a major pathway for the transfer of Pb within Ofi cladodes. The stomata, areoles, and cuticle of cladode surface, play an obvious role in the retention and the incorporation of lead-bearing apatite, thus revealing the hazard of eating contaminated cladodes. The possibility of using series of successive cladodes for biomonitoring the atmospheric pollution in arid and semi-arid regions is also rapidly discussed