Évaluation du comportement géochimique à long terme de rejets miniers à faible potentiel de génération d'acide à l'aide d'essais cinétique

L'industrie minière et ses rejets -- Le drainage minier acide -- Objectifs et contenu du mémoire -- Présentation des essais cinétiques -- Études comparatives sur les essais cinétiques -- Méthodes de caractérisation des échantillons solides -- Méthodes de caractérisation des échantillons liquides -- Essais cinétiques -- Nature et historique des échantillons -- Caractéristiques physiques -- Analyse des métaux et des principaux anions -- Minéralogie -- Essais statiques -- Données ponctuelles -- Données cumulatives -- Facteurs influençant les résultats des essais cinétiques -- Potentiel de génération d'acide des rejets étudiés -- Outil de sélection

Les conflits urbains : une approche analytique

Cette note de recherche aborde premièrement quelques questions de base concernant les conflits urbains. Qu’est ce qu’un conflit urbain? Quels rôles les conflits jouent-ils dans les transformations des milieux de vie? Comment ces conflits en sont-ils venus à occuper le devant de la scène au cours des dernières décennies? Le texte illustre ensuite une approche analytique susceptible de compléter les études de cas qui constituent la démarche habituelle dans la recherche sur les conflits. Cette démarche utilise la presse écrite comme principale source de données et la modélisation statistique comme principale méthode d’analyse.This research note begins by examining some basic questions relating to urban conflicts. What is an urban conflict? What are the roles played by conflicts in the transformation of urban environments? How have such conflicts gained so much prominence in recent decades? The note then proposes an analytical approach capable of expanding case studies, which are the standard method used in research on conflicts. In this approach, newspapers are selected as the primary data source and the method of analysis relies heavily on statistical modelling

Analyse spatiale des conflits urbains : Enjeux et contextes dans la région de Québec

Cette étude exploratoire des conflits urbains de la région de Québec entre 1990 et 2000 montre que la fréquence des conflits est plus élevée dans les secteurs où, d’une part, la densité de commerces de quartier est la plus forte et le tissu urbain plus ancien et, d’autre part, où la population est la plus scolarisée et dispose d’un horaire de travail flexible. Cette étude confirme ainsi que certains cadres urbains sont plus susceptibles que d’autres de générer des conflits et que certains groupes sont plus disposés à s’y engager. Elle montre aussi que ces relations sont sensiblement les mêmes, quel que soit le type d’enjeux défendus par les protagonistes de ces conflits. Deux exceptions sont toutefois à relever. Tout d’abord, les conflits liés à des enjeux environnementaux montrent parfois des relations différentes avec les variables caractérisant les lieux de conflits (indépendamment du niveau d’éducation et le type de profession). Ensuite, alors que la densité de population n’a dans l’ensemble pas d’influence sur l’émergence des conflits, on observe tout de même que dans les secteurs où la population est la plus dense, les conflits liés à des enjeux de transports ou des enjeux sociaux sont plus nombreuxThis paper investigates urban conflicts that took place in the Quebec City metropolitan area between 1990 and 2000. Analyses show that some population groups are more disposed than others to get involved in conflict activity. They also stress that there are specific built environments which are more prone than others to generating such activity. Statistical analysis of seven variables related to social and urban contexts shows that the frequency of conflicts is greater, on the one hand, in areas where small shop density is the highest and buildings are the oldest, and on the other, where the population has high levels of education and a flexible work schedule. Analyses considering what is at stake present similar results, except on two points. First, conflicts with environmental stakes do not appear to be linked to a particular level of education or a flexible work schedule. Thus even if population density shows statistical independence from all variables when the conflicts are considered as a whole, it appears specifically dependent with respect to conflicts involving transportation or social stakes

Les conflits urbains : une approche analytique

Cette note de recherche aborde premièrement quelques questions de base concernant les conflits urbains. Qu’est ce qu’un conflit urbain? Quels rôles les conflits jouent-ils dans les transformations des milieux de vie? Comment ces conflits en sont-ils venus à occuper le devant de la scène au cours des dernières décennies? Le texte illustre ensuite une approche analytique susceptible de compléter les études de cas qui constituent la démarche habituelle dans la recherche sur les conflits. Cette démarche utilise la presse écrite comme principale source de données et la modélisation statistique comme principale méthode d’analyse.This research note begins by examining some basic questions relating to urban conflicts. What is an urban conflict? What are the roles played by conflicts in the transformation of urban environments? How have such conflicts gained so much prominence in recent decades? The note then proposes an analytical approach capable of expanding case studies, which are the standard method used in research on conflicts. In this approach, newspapers are selected as the primary data source and the method of analysis relies heavily on statistical modelling

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

Hepatic Arterioportal Shunts: Dynamic CT and MR Features

With the increased temporal resolution available in dynamic computed tomography (CT) and magnetic resonance imaging (MRI), hepatic arterioportal shunts are now more frequently encountered than in the past. The condition occurs in various hepatic diseases in which portal or hepatic venous flow is compromised. The underlying mechanism and the degree of shunt affect its appearance at dynamic imaging. The dynamic CT and MRI findings have been summarized as early enhancement of peripheral portal veins, and wedge-shaped transient parenchymal enhancement during the hepatic arterial phase. Recognition of arterioportal shunt can suggest the presence of a previously unsuspected disorder and avoids false-positive diagnosis or overestimation of a hepatic disease. Familiarity with the pathophysiology of arterioportal shunt also allows investigation of the hepatic hemodynamic changes occurring in various hepatic diseases

It's getting hot in here – Microcontextual study of a potential pit hearth at the Middle Paleolithic site of El Salt, Spain

By studying combustion structures, which conceal information about anthropogenic activity, we might learn about their makers. This is especially important for remote time periods like the Middle Paleolithic, whose archaeological record comprises numerous combustion structures. The majority of these are simple, flat, open hearths, although a small number of features situated in pit-like depressions have been recorded. Given that hearths built on a flat surface can result in pit-like color alteration of the underlying sediment, accurate identification of pit hearths is a crucial step prior to behavioral interpretation. Here we present a comprehensive study of a possible pit hearth from the Middle Paleolithic site of El Salt, Spain, using a microcontextual approach combining micromorphology, lipid biomarker analysis, archaeomagnetism and zooarchaeology. This pit hearth involves a true depression containing a thick plant ash deposit. It reached very high temperatures, possibly multiple burning events and long combustion times. Morphologically distinct combustion structures in a single archaeological context may indicate different functions and thus a diverse fire technology, pointing to Neanderthal behavioral variability.ERC Consolidator Grant project PALEOCHAR – 648871 https://erc.europa.eu/funding/consolidator-grants, I + D Project HAR2008-06117/HIST, HAR2015-68321-P (MINECO-FEDER/UE), and the Cultural Heritage Department of the Valencia Government and the Archaeological Museum Camil Visedo of Alcoy, under the direction of Professor Bertila Galván of Universidad de La Laguna, Junta de Castilla y León (project BU235P18), the European Fund for Economic and Regional Development (EFRD) and the project PID2019-105796 GB-I00 of the Agencia Estatal de Investigación (AEI/10.13039/501100011033

Amyloid and tau pathology associations with personality traits, neuropsychiatric symptoms, and cognitive lifestyle in the preclinical phases of sporadic and autosomal dominant Alzheimer’s disease

Background Major prevention trials for Alzheimer’s disease (AD) are now focusing on multidomain lifestyle interventions. However, the exact combination of behavioral factors related to AD pathology remains unclear. In 2 cohorts of cognitively unimpaired individuals at risk of AD, we examined which combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle (years of education or lifetime cognitive activity) related to the pathological hallmarks of AD, amyloid-β, and tau deposits. Methods A total of 115 older adults with a parental or multiple-sibling family history of sporadic AD (PREVENT-AD [PRe-symptomatic EValuation of Experimental or Novel Treatments for AD] cohort) underwent amyloid and tau positron emission tomography and answered several questionnaires related to behavioral attributes. Separately, we studied 117 mutation carriers from the DIAN (Dominant Inherited Alzheimer Network) study group cohort with amyloid positron emission tomography and behavioral data. Using partial least squares analysis, we identified latent variables relating amyloid or tau pathology with combinations of personality traits, neuropsychiatric symptoms, and cognitive lifestyle. Results In PREVENT-AD, lower neuroticism, neuropsychiatric burden, and higher education were associated with less amyloid deposition (p = .014). Lower neuroticism and neuropsychiatric features, along with higher measures of openness and extraversion, were related to less tau deposition (p = .006). In DIAN, lower neuropsychiatric burden and higher education were also associated with less amyloid (p = .005). The combination of these factors accounted for up to 14% of AD pathology. Conclusions In the preclinical phase of both sporadic and autosomal dominant AD, multiple behavioral features were associated with AD pathology. These results may suggest potential pathways by which multidomain interventions might help delay AD onset or progression

Comparative field study of shallow rhyolite intrusions in Iceland:emplacement mechanisms and impact on country rocks

Shallow silicic intrusions are known to exist in many active volcanoes and can fuel both eruptions and hydrothermal fields. However, our knowledge of magma intrusions remains far from complete, and processes occurring at intrusion margins are poorly understood. In this field-based study, we characterise four shallows, dissected rhyolitic intrusions at three sites in Iceland (Njarðvík-Dyrfjöll, Krafla and Húsafell central volcanoes). We focus on the relationship between intrusion emplacement mechanisms and country rock response, employing scanline mapping of fractures and in-situ rock property measurements (hardness and permeability) along transects from the intrusion margins to damaged and undamaged country rocks.We identify various scenarios of shallow intrusion emplacement style, based upon their diverse geometry and lithofacies architecture. Additional information from rock properties and characteristics of fractures and vesicles, indicates that initial country rock properties strongly influence the emplacement style. We identify two discrete types of country rock response to magma injection. The matrix permeability of weak, porous and permeable lithologies (conglomerate and hyaloclastite) is reduced by >1 order of magnitude adjacent to intrusions due to pore occlusion. Stronger and denser, low-permeability lithologies (basalt and welded ignimbrite) undergo a decrease in hardness by a factor >2 related to an up to fivefold increase in fracture density, with no significant change in matrix permeability.Our observations highlight the importance of robust characterisation of the mechanical properties of caldera-filling or geothermal reservoir formations, for appropriate forecasting of magma mobility, geophysical data interpretation, and geothermal resources characterisation