Après la découverte au Large Hadron Collider (LHC) d'un boson de Higgs compatible avec celui du modèle standard, les futurs projets de collisionneurs tels que le Collisionneur Linéaire International ILC sont proposés pour succéder au LHC. Les deux détecteurs proposés pour être placés au point de collision de l'ILC, le Grand Détecteur International ILD et le Détecteur en Silicium SiD, seront des détecteurs généralistes, conçus pour permettre l'application des algorithmes de suivi de particules, principal sujet d'intérêt de cette thèse. Le calorimètre hadronique à lecture semi-digitale SDHCAL développé essentiellement à l'IPN de Lyon, fait partie des options pour le calorimètre hadronique du détecteur ILD. Les travaux effectués dans cette thèse portent sur le développement d'un algorithme de suivi de particules basé sur la topologie en arbre des gerbes hadroniques. Après une première implémentation pour le prototype du SDHCAL d'une taille d'un mètre cube, une seconde implémentation est proposée pour reconstruire les particules issues des collisions dans le détecteur ILD. A l'aide de données issues de simulations numériques, les performances physiques sont extraites. Dans le cas de la version dédiée au prototype du SDHCAL, les résultats sont comparés aux données récoltées lors des différents tests sur faisceau.En parallèle de ces travaux, un logiciel de surveillance de données en ligne générique nommé DQM4HEP a été développé. Des analyses spécifiques aux données récoltées par le prototype du SDHCAL lors des divers tests sur faisceau, ont été déployées afin de tester le logiciel / After the discovery of a Higgs boson compatible with the standard model one at the Large Hadron Collider (LHC), future project of particle colliders such as the ILC are suggested to succeed the LHC. The two detectors at the collision point, the International Large Detector (ILD) and the Silicon Detector (SiD), are generalist detectors, deigned to allow the application of particle flow algorithms, main topic of interest of this thesis.The semi-digital hadronic calorimeter (SDHCAL), mainly developped at the IPNL, is one the options for the hadronic calorimeterof the ILD detector. The researches presented in this thesis are focused on particle flow development based on the tree topology of hadronic showers. After a first implementation for the SDHCAL physics prototype, a second one is proposed to reconstruct the particles from collisions in the ILD detector. Using Monte-Carlo data samples, physics performances are extracted. In the first version case, results are compared to available test beam data recorded by the SDHCAL prototype at CERN.In parrallel of this work, a data quality monitoring framework, called DQM4HEP, has been developped. Analyzes specific to SDHCAL data taken during beam tests have been deployed in order to test the software

Objectifs. Évaluer la réponse de l'utilisation d'acide acétylsalicylique (AAS) à faible dose avec l'appareil PFA-100 par le temps d'occlusion avec épinéphrine (CEPI-TO) chez des patientes enceintes. Étudier les différents déterminants de la non-réponse à l'AAS ainsi que les variations du CEPI-TO selon l'âge gestationnel. Étudier, de façon exploratoire, les issues obstétricales des patientes non répondantes à l'AAS. Étude cohorte prospective. Lieu. Centre hospitalier universitaire Hôpital Sainte-Justine, à Montréal, Québec. Population. 87 patientes enceintes utilisant de l'AAS faible dose en prophylaxie pour différentes indications. Parmi ces patientes, 37.6 % utilisaient de l'AAS en raison d'antécédents d'hypertension gestationnelle ou de restriction de croissance intra-utérine lors d'une grossesse précédente. Pertinence de l'étude. La population obstétricale n'a pas fait l'objet, jusqu'à ce jour, de l'évaluation du phénomène de la non-réponse à l'AAS tel qu'on l'observe dans d'autres domaines tels que la cardiologie et la neurologie. Issues mesurées. Proportion de patientes répondantes à l'AAS mesurée avec l'appareil PFA-100 par le CEPI-TO selon la dose d'AAS utilisée et le moment de la grossesse. Les caractéristiques maternelles et issues de grossesse des patientes ont été mesurées à l'aide du suivi et du dossier médicale des patientes. L'appareil PFA-100 est un équipement mesurant le temps d'occlusion d'un capillaire à la formation d'un thrombus plaquettaire en présence de collagène. Résultats. Après 4 semaines d'utilisation d'AAS enrobée 81 mg pris quotidiennement, 25/87 patientes obtenaient un CEPI-TO < 150 sec (28,7 %, 95 % IC 16.1 à 41.4). Chez ces patientes non répondantes à 81 mg d'AAS, la dose fut augmentée à 81 mg pris en alternance avec 162 mg; 8/24 (33,3 %, 95 % IC 5.4 à 23.3) patientes sont demeurées non répondantes. Dans ce groupe de patientes non répondantes, la dose d'AAS fut alors augmentée à 162 mg quotidiennement et 3/6 (50 %) patientes sont restées non répondantes malgré les augmentations de doses répétées. Chez les femmes enceintes initialement répondantes (CEPI-TO > 150 sec) à 81 mg d'AAS, un CEPI-TO a été contrôlé entre 24-32 semaines de grossesse et 9/36 patientes ont démontré un CEPI-TO < 150 sec. Quoique la puissance de l'étude ne permet pas de statuer définitivement sur chacun des déterminants de la non-réponse à l'AAS, aucune différence en termes d'âge, de poids, d'ethnicité, d'utilisation de tabac, du nombre de semaines de gestation au moment de l'introduction de l'AAS ou du nombre de semaines de grossesse au moment de la première mesure du CEPI-TO, n'a été démontrée entre les patientes répondantes à 81 mg d'AAS et les non-répondantes. Chez les patientes initialement répondantes à 81 mg d'AAS, 42/62 patientes (67,7 %) ont eu une grossesse sans événement, 16/62 (25,8 %) ont présenté une complication obstétricale et chez les patientes non-répondantes 16/25 patientes (64,0 %) ont aussi eu une grossesse dite normale, 7/25 (28,0 %) ont présenté une complication obstétricale. Étant donné la faible taille de l'échantillon chez les patientes présentant des complications, l'efficacité de l'AAS et l'influence de la non-réponse à l'AAS n'ont pas été mesurées. Conclusion. Plusieurs femmes enceintes ont démontré leur non-réponse à l'utilisation d'AAS enrobée à des doses de 81 mg lorsque analysées par CEPI-TO. Notre étude a démontré que la non-réponse à l'AAS est dose-dépendante et qu'elle peut être renversée chez la plupart des patientes lorsque l'on utilise des doses plus élevées. De plus, la non-réponse à l'AAS semble aussi apparaître chez un certain nombre de patientes lorsque la grossesse avance en âge.

Tatera brantsii was numerically dominant in the small mammal community on the plateaux of the rehabilitated ash disposal sites of ESKOM's Hendrina Power Station in 1998 and 1999 (Vermaak 2000). The species seemed well adapted to exploit this environment and, through biopedturbation, had altered the topsoil structure and chemistry. The consequences of this and other activities also affected the rehabilitated plant community of the PFA-dam habitat. Burrowing appeared limited to just under the topsoil layer, and seemed more extensive than burrows of this species in natural ecosystems. The burrow system architecture was mapped and quantified, and localised increases in nitrates, phosphorous and organic carbon in immediately associated substrate were noted. However, this substrate enrichment was transient, and disappeared following the abandonment, and subsequent collapse of burrow systems, when gerbil colonies migrated away from the area. The mixing of soil horizons also resulted in a more homogeneous substrate, which was more friable, and thus drier. The high pH and salinity of the topsoil layer in areas undisturbed by gerbil burrowing, and concentrations of particular elements associated with either the topsoil covering or the ash, were reduced as a consequence of substrate mixing in disturbed areas. Gerbil impacts on the substrate of this habitat seemed to promote pedogenesis, eliminating the sharp distinction between the topsoil covering and the ash below, but the re-exposed ash of the burrow mounds would become subject to erosion, and reduce the effectiveness of the rehabilitation effort. Gerbil activities increased the number of plant species, especially ruderal forbs, comprising the plant community of the PFA-dam habitat, but plant community diversity was not significantly increased. However, numerical dominance by few tussock grass species was diminished , possibly reflecting burial under mounds of excavated substrate. The biomass and cover of some grass species were reduced in areas of gerbil impacts, and plant lifecycles appeared to be completed sooner in areas affected by gerbil activities. These effects may be as a result of the drier substrate produced following the collapse of the extensive network of abandoned burrows. The succession of this plant community towards an underutilised grassland state, the expected outcome of the rehabilitation effort, was minimally affected by gerbil activities. The effects of T.brantsii activities in this PFA-dam habitat were not as distinct as the effects noted by other authors studying fossorial rodent impacts in less disturbed habitats. This could be because further disturbances in this habitat would merely add to the currently disturbed state, whereas disturbance in more natural habitats, would show more of a change from the initial state. / Thesis (M.Sc. (Zoology))--North-West University, Potchefstroom Campus, 2007.

Tatera brantsii was numerically dominant in the small mammal community on the plateaux of the rehabilitated ash disposal sites of ESKOM's Hendrina Power Station in 1998 and 1999 (Vermaak 2000). The species seemed well adapted to exploit this environment and, through biopedturbation, had altered the topsoil structure and chemistry. The consequences of this and other activities also affected the rehabilitated plant community of the PFA-dam habitat. Burrowing appeared limited to just under the topsoil layer, and seemed more extensive than burrows of this species in natural ecosystems. The burrow system architecture was mapped and quantified, and localised increases in nitrates, phosphorous and organic carbon in immediately associated substrate were noted. However, this substrate enrichment was transient, and disappeared following the abandonment, and subsequent collapse of burrow systems, when gerbil colonies migrated away from the area. The mixing of soil horizons also resulted in a more homogeneous substrate, which was more friable, and thus drier. The high pH and salinity of the topsoil layer in areas undisturbed by gerbil burrowing, and concentrations of particular elements associated with either the topsoil covering or the ash, were reduced as a consequence of substrate mixing in disturbed areas. Gerbil impacts on the substrate of this habitat seemed to promote pedogenesis, eliminating the sharp distinction between the topsoil covering and the ash below, but the re-exposed ash of the burrow mounds would become subject to erosion, and reduce the effectiveness of the rehabilitation effort. Gerbil activities increased the number of plant species, especially ruderal forbs, comprising the plant community of the PFA-dam habitat, but plant community diversity was not significantly increased. However, numerical dominance by few tussock grass species was diminished , possibly reflecting burial under mounds of excavated substrate. The biomass and cover of some grass species were reduced in areas of gerbil impacts, and plant lifecycles appeared to be completed sooner in areas affected by gerbil activities. These effects may be as a result of the drier substrate produced following the collapse of the extensive network of abandoned burrows. The succession of this plant community towards an underutilised grassland state, the expected outcome of the rehabilitation effort, was minimally affected by gerbil activities. The effects of T.brantsii activities in this PFA-dam habitat were not as distinct as the effects noted by other authors studying fossorial rodent impacts in less disturbed habitats. This could be because further disturbances in this habitat would merely add to the currently disturbed state, whereas disturbance in more natural habitats, would show more of a change from the initial state. / Thesis (M.Sc. (Zoology))--North-West University, Potchefstroom Campus, 2007.

Le paludisme, maladie infectieuse due à des parasites du genre Plasmodium, reste mortel et préoccupant dans les régions intertropicales d’Afrique, d’Asie et d’Amérique. Les phénomènes de résistance des parasites aux différentes générations de traitements représentent un problème majeur, auxquels s’ajoutent le coût des traitements et donc l’accès aux soins pour les populations les plus défavorisées. Il est ainsi urgent de trouver de nouvelles cibles et de développer de nouveaux agents antipaludiques agissant via des mécanismes originaux. La cible étudiée lors de ces travaux de thèse est la leucyl aminopeptidase bimétallique de P. falciparum, notée PfA-M17. Elle a récemment émergé comme potentielle cible antipaludéenne et jouerait un rôle essentiel à la croissance et à la survie du parasite. Elle serait impliquée dans la dernière étape du catabolisme de l’hémoglobine lors du cycle érythrocytaire du parasite. Ces travaux se sont concentrés sur la conception, la synthèse et l’évaluation d’inhibiteurs sélectifs de PfA-M17. En s’inspirant de travaux antérieurs menés au laboratoire et d’expériences de modélisation moléculaire, des analogues benzocycloheptanes trisubstitués ont été conçus pour inhiber sélectivement PfA-M17. Une voie de synthèse diastéréosélective partant de l’acide D-isoascorbique a été mise au point et a permis d’accéder à des analogues cycloheptanes et cyclohexanes trisubstitués. Cette voie de synthèse a aussi été étudiée afin d’obtenir des analogues benzocycloheptanes trisubstitués. / Malaria is an infectious disease due to Plasmodium parasites, still causing numerous deaths in intertropical areas of Africa, America and Asia. Existing treatments face problems of high cost and resistance, hence the need to discover new targets and to develop new compounds. This work focused on a recent antimalarial target, a bimetallic leucyl aminopeptidase, named PfA-M17. Inhibition of this aminopeptidase shows it is essential for parasite survival and growth. PfA-M17 may be involved in the last step of hemoglobin digestion during the intraerythrocytic cycle of the parasite. This study concerned the design, the synthesis and the evaluation of selective PfA-M17 inhibitors. Trisubstituted benzocycloheptane analogs were designed as PfA-M17 inhibitors, based on previous works performed in our team and based on molecular modelling. A diastereoselective pathway was developed from D-isoascorbic acid and gave trisubstituted cycloheptanes and cyclohexanes analogs. This pathway was also studied in order to get the trisubstituted benzocycloheptane scaffolds.

No description available.

The aim of the project is to utilise fly ash (PFA), a waste material/industrial byproduct, with metakaolin (MK), as a partial replacement for Portland cement (PC) in mortar and paste. The influence of various compositions of MK-PFA-PC blends on the resistance to the action of sulphate and synthetic seawater solutions, setting time and heat of hydration will be examined. MK is calcinated clay and is a relatively new pozzolanic material. Although it is a very effective pozzolan it is also very expensive. Using FA, which is a much less expensive material, as a PC replacement material, is problematic, as there is slow and low early strength development whereas MK enhances early strength development. Combining these materials in ternary blends should therefore produce a high performance material at an acceptable cost for use as a pozzolan. However the properties and performance of such a material still need to be fully established. The results of the research show, for the initial and final setting time of binary MK-PC pastes there is a substantial increase at 5% MK and then decreases at 10 and 15% MK before increasing again at 20% MK replacement level. However, with PFA there are different trends to those observed when using MK alone. The initial and final setting time of binary PFA-PC pastes shows a slight increase at 10% PFA and then systematically increases with increase in PFA content up to 40% PFA. Evaluation of sample preparation for porosimetry found that, overall, the compression tested samples show a lower proportion of 'fine pores' (volume (%) 0.05) jam than the cored and cut paste disks. It is deducted that this is due to the widespread microcracking during failure of the cubes under compressive loading thus modifying the pore structure present in the compressive tested samples. In strength development of mortar there is very little advantage in using MK over binary PFA-PC mortar blends when exposed to sulphate solution for up to 2 years. The strength behaviour in seawater is however quite different from that observed in mortar exposed to sulphate solution. As the MK replacement levels increase relative to the PFA levels the resistance to seawater attack improves significantly. In mortar exposed to sulphate solution the durability is greatly improved at high replacement levels in both binary and ternary blends. The durability of mortar exposed to seawater is greatly improved at 30 and 40% total replacement in ternary blended mortars.

Cement-less and/cement-like geopolymer mortars were made with pulverised fuel ash (PFA) or ground granulated blast furnace slag (GGBS) activated by alkali with different alkali moduli (AM) and alkali dosage (AD). Once synthesised the samples were cured at 20°C and 70°C up to 28 days. The flexural and compressive strengths of these samples at early ages up to 28 days were tested conforming to BS EN196-1:2005. The electrical resistivity of these materials was monitored using a set of non-contacting electrodes to the age up to 7 days to characterise the geopolymerisation process from a physical phenomenon point of view. The effects of AD and AM on the early-age mechanical strengths and electrical resistivity of geopolymer materials were examined from the experimental results. The correlation between strength development and electrical resistivity was studied. The geopolymerisation process was characterised by a 5-stage model, based on electrical resistivity, analogue to hydration process of Portland cement. This research therefore proposes an alternative method for characterisation of geopolymerisation of geopolymers different from traditional methods based on chemistry. It is expected that such a physical phenomenon model will be better accepted by structural engineers for better promotion of usage of geopolymer composites, a type of low carbon and more sustainable binder-based materials, in construction.

No description available.

No description available.