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Top pair production cross sections and differential cross sections in the semi-leptonic channel using the CMS detector at √s = 7 and 8 TeVSymonds, Philip January 2015 (has links)
The top quark has been extensively studied since the Large Hadron Collider (LHC) began operating in 2010. The excellent performance of both the LHC and the Compact Muon Solenoid (CMS) detector has enabled complex analyses of many properties of the top quark. In this thesis inclusive and differential top pair (tt) production cross sections have been measured. Inclusive tt cross sections of 145.6 ± 8.2 (stat.) +38.1/28.3 (syst.) pb and 237.4 ± 1.9 (stat.) +20.4/-16.9 (syst.) pb were measured at 7 TeV and 8 TeV center-of-mass collision energies using luminosities of 1 fb⁻¹ and 19.7 fb⁻¹, respectively. These measurements were performed in the semi-leptonic channel by means of a maximum likelihood t of the lepton's pseudorapidity. The work in this thesis focuses specifically on the muon-plus-jets channel. The methods used for measuring the inclusive cross sections were built upon to measure differential cross sections with respect to event level observables. These observables include the missing transverse energy (Emiss T ) as well as some other kinematic distributions involving the jets, lepton and Emiss T in the decay. These results are unfolded to remove detector and selection effects and have uncertainties in the range of 3% to 15%. A low uncertainty is achieved by normalising the differential cross section using the total cross section. This leads to cancellations of some uncertainties. The results were compared with different Monte Carlo generators and with different input parameters. No significant deviations from predictions of the Standard Model were observed. This thesis also contains test beam results on CMS ECAL Endcap Lead Tungstate (PbWO4) crystals. These crystals had been damaged using various doses of proton irradiation. The damage for some crystals is expected to be roughly equivalent to 300 fb-1 of integrated luminosity at √s = 14 TeV. The energy resolution for these crystals was seen to reduce by close to a factor of 20.
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Interactions hippocampo-corticales au cours de la consolidation d’informations spatiales chez la souris : approche anatomo-fonctionnelle et recherche des facteurs modulantsAlaux Cantin, Stéphanie 19 December 2008 (has links)
La théorie standard de la consolidation mnésique postule que le stockage à long terme des souvenirs, initialement dépendant de la formation hippocampique, s’effectuerait par l’intermédiaire d’un dialogue hippocampo-cortical au cours duquel l’hippocampe (HPC) se désengagerait progressivement jusqu’à ce que le néocortex devienne à lui seul capable de sous-tendre le rappel des souvenirs. Plusieurs études réalisées chez l’animal, notamment dans le paradigme du labyrinthe à 5 bras validé par l’équipe, confortent cette théorie. Cependant, une exception à ce mode de consolidation est observée dans la tâche de navigation spatiale du labyrinthe aquatique de Morris pour laquelle l’HPC est impliqué de façon permanente dans le rappel quel que soit l’âge des souvenirs. Cette observation a conduit à relancer le débat sur la validité du modèle standard de la consolidation au profit de la théorie des traces multiples (TTM) qui plaide en faveur d’une implication permanente de l’hippocampe lors du rappel d’informations complexes, de nature spatiale ou épisodique. La résolution de la tâche de navigation pourrait en effet nécessiter une intégration spatiale plus complexe que dans le labyrinthe à 5 bras susceptible d’expliquer l’implication durable de la région hippocampique. Ces observations nous ont amenés à réévaluer la composante spatiale du labyrinthe à 5 bras et à développer un nouvel appareil, le labyrinthe à 7 bras, présentant un certain nombre d’innovations. Dans cet appareil, les animaux doivent apprendre à localiser l’unique bras appâté (mémoire de référence) grâce à l’utilisation d’indices spatiaux. Deux versions du protocole ont été mises au point afin de moduler la demande spatiale de la tâche : une version à point de départ fixe (VPF) et une version à points de départ multiples (VPM) (...) Ces travaux nous conduisent à proposer un modèle de fonctionnement de l’interface hippocampocorticale qui intègre la nature et la complexité des représentations mnésiques comme des éléments modulateurs déterminants de la dynamique du dialogue hippocampo-cortical au cours du processus de consolidation mnésique. / Abstract
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Optimisation de l'utilisation de l'imagerie TEP pour la planification de traitement en radiothérapieLe Maitre, Amandine 03 July 2012 (has links)
La Tomographie par Émission de Positon (TEP) combinée à l'imagerie scanner est intéressante pour la planification de traitement en radiothérapie. Elle réduit la variabilité inter et intra-observateur dans la définition du volume cible et permet de visualiser les hétérogénéités biologiques. Plusieurs algorithmes de segmentation ont été proposés mais aucun ne fait consensus. Pour valider ces algorithmes, les simulations de Monte-Carlo offrent la possibilité de maîtriser la vérité terrain et l'ensemble des paramètres d'acquisition.Nous avons proposé plusieurs méthodologies d'amélioration du réalisme des simulations. Des jeux de données présentant une variabilité anatomique, une hétérogénéité tumorale réaliste et intégrant les mouvements respiratoires ont ainsi été générés.Ces données ont été utilisées dans une première étude sur la segmentation du volume cible. Plusieurs algorithmes ont été comparés dans le cadre de la planification de traitement. L'utilisation de données simulées a permis de relier la précision de la segmentation à la qualité de la couverture de la vérité terrain. Nous avons aussi étudié l'impact de la respiration sur la précision de la segmentation.L'utilisation d'un algorithme de segmentation avancé permettant de définir un sous-volume plus actif pour la prescription d'une dose hétérogène a été proposée. Plusieurs scénarios de prescription ont été comparés en terme de probabilité de contrôle tumorale (TCP) calculée sur la TEP. La variabilité de la TCP liée aux paramètres d'acquisitions a été quantifiée. L'impact du contraste et de la taille du sous-volume fut étudié. Pour finir l'apport d'un ajout de compartiments à de telles prescriptions a été analysé. / There has been an increasing interest for the use Positron Emission Tomography (PET) combined with Computed Tomography for radiotherapy treatment planning. It improves target volume delineation by reducing inter and intra-observer variability and allows visualizing biological heterogeneities. Plethoras of segmentation algorithm have been proposed but there is a lack of consensus regarding which one to use. Monte Carlo simulations are interesting to validate these algorithms since they allow creating datasets with known ground-truth and for which all acquisition parameters are controlled.We proposed several methodologies for improving the realism of simulations. Several datasets incorporating patient specific variability in terms of anatomy and activity distributions, realistic tumor shape and activity modeling and integrating the respiratory motions were created.These data were used in a first study concerning target volume definition. Several algorithms were compared for radiotherapy treatment planning. The accuracy of segmentation was related to the quality of ground-truth volume coverage. We also studied the impact of respiratory motion on segmentation accuracy.We investigated the use of an advanced segmentation method able to define high uptake sub-volumes, for heterogeneous dose prescriptions. Several scenarios of prescriptions were compares in terms of Tumor Control Probability (TCP) computed on PET images. Variability of this TCP due to acquisition parameters was quantified. The impact of contrast and size of sub-volume was studied. Finally we studied the usefulness of the addition of compartments to such heterogeneous prescriptions.
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Adheze, růst a potenciálníimunitní aktivace buněk na kovových materiálech pro kostní implamplantáty. / Adhesion, growth and potential immune activation of cells on metallic materials for bone implants.Straňavová, Lucia January 2013 (has links)
The contemporary orthopaedics and traumatology of the musculoskeletal system and stomatology have been witnessing a substantial increase in the number of surgeries using metallic implants. The issue of reconstruction of bone defects covers a large area of study, where the surface properties of the implants are extremely important. Bone defects often occur as a result of open fractures, radical cancer treatment or limb lengthening, which is very common in paediatric orthopaedics. In the treatment of these conditions, the surface of the applied materials should provide a favorable environment for bone cells and support bone formation. In endoprosthetics it is highly desirable to achieve the strongest possible fixation between the implant surface and the bone. During the surgery, primary stability of the implant fixation is ensured by the proper positioning of the implant, based on the appropriate shape of the implant and the quality of bone cut. The initial stability is only temporary, being estimated to last approximately three months. After this period, the secondary stability starts, determined by the bone ingrowth into the implant surface structure. Osteogenic differentiation and extracellular matrix (ECM) mineralization can be enhanced by the presence of bone morphogenetic proteins (BMPs),...
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Příprava, financování a realizace projektu 7. rámcového programu EU v oblasti ICT / Preparation, financial aspects and realization of EU 7th Framework Programme in ICTKašparová, Lenka January 2010 (has links)
This Thesis analyze organizational administrative steps and impact of integration of extensive EU 7th Framework Programme from Research and Development area into current small-medium company environment with foreign capital in local Czech market. Thesis pointing out to one of many ways of project implementation into intradepartmental structure it`s complexity and possible difficulties. The practical part analyses initial phase of the project, concrete deprivation, mistakes taken during implementation phase and than practical financial, administrative, legal and organizational recommendations.
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Modulating the T cell response: using anti-interleukin-7 receptor-alpha monoclonal antibodies with autoantigen-specific immunotherapy to prevent type-1-diabetesLawson, Maxx 09 August 2019 (has links)
Autoimmunity develops over an extended period of time as the result of an amalgamation of genetic, environmental, and immunologic events. Though the precise etiological factors leading to most autoimmune disease are awaiting consensus, a common thread of the autoimmune paradigm is the inappropriate activation of tissue-specific immune cells by one or more autoantigen, which begins the destruction of the tissue. To prohibit immunopathology and fine-tune the immune responses in healthy individuals, the stimulatory activities of effector/memory T (Teffs) cells must be counteracted by the suppressive mechanisms of regulatory T cells (Tregs). Thus, the potential to modulate the ratio between Teff and Tregs in autoimmune patients has been widely investigated with high hopes to permanently cure certain autoimmune diseases such as type 1 diabetes militus (T1D). Autoantigen therapies, which attempt to induce Tregs to suppress pathogenic effector cells in an autoantigen-specific manner, have shown efficacy in preventing T1D in mice, but have largely failed in clinical trials. One approach to improve the effectiveness of islet autoantigen vaccinations is to combine them with an additional modulator of the T cell response which favors a regulatory phenotype. In the work presented here, we asked whether the addition of anti-interleukin-7 receptor-alpha (anti-IL-7Rα) monoclonal antibodies (mAbs) to islet autoantigen immunizations would modulate the T cell response and prevent T1D in non-obese diabetic (NOD) mice. It was found that anti-IL-7Rα mAbs reduced the absolute numbers of islet antigen-specific T cells when immunized with islet peptide in conjunction with the commonly used vaccine adjuvant alum. Such treatments were also observed to increase nonspecific IL-2, IFN-𝛾, and IL-10 cytokine production, resulting in no improvement of T1D onset prevention. In another approach, we generated a conjugate vaccine by conjugating islet autoantigens to the immunogenic carrier protein, Keyhole Limpet Hemocyanin (KLH). We found that islet antigen-KLH (Ag-KLH) vaccination resulted in significant expansion of the desirable antigen-specific Tregs. Further, Ag-KLH immunization successfully delayed, and in some cases entirely prevented, T1D onset in NOD mice. Indicating that KLH-conjugated vaccine may represent a promising approach for future autoantigen therapies against autoimmunity. Interestingly, administration of anti-IL-7Rα mAbs did not improve these outcomes. To the contrary, we again observed excessive nonspecific cytokine production induced by IL-7Rα blockade that inhibited the beneficial effects of Ag-KLH vaccination. Taken together, we concluded that the addition of anti-IL-7Rα mAbs did not improve the efficacy of autoantigen vaccinations to prevent T1D. Significant work still remains to better characterize and isolate the beneficial effects of anti-IL-7Rα mAbs to treat autoimmunity.
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Die funktionelle Bedeutung der Heteromerisierung von Serotonin-1A und Serotonin-7 Rezeptoren / Functional importance of heteromerisation of serotonin-1A and serotonin-7 receptorsFröhlich, Matthias January 2011 (has links) (PDF)
Die Heterodimerisierung von G- Protein gekoppelten Rezeptoren (GPCR) stellt ein aktuelles Forschungsgebiet dar, das molekulare Erklärungsmöglichkeiten für die Vielfalt der Signalwege über solche Rezeptoren aufzeigt. Die genauen Funktionen diese Konstrukte in vivo sind bisher erst in Ansätzen erforscht, ebenso wenig die molekularbiologischen Mechanismen. Für die beiden Serotoninrezeptoren 5-HT1A und 5-HT7 konnte Heterodimerisierung molekular nachgewiesen werden, in ihren physiologischen Mechanismen und Effekten sollte daher eine Charakterisierung vorgenommen werden. Mittels elektrophysiologischer Messverfahren wurden Ströme an dem heterologen Expressionsmodell der Oozyten des Krallenfrosches Xenopus laevis mittels Voltage-Clamp Technik an Kaliumionenkanälen (Kir3 und TASK-1) gemessen. Hierbei konnte gezeigt werden, dass die heterodimere Koexpression beider Rezeptoren eine signifikante Reduktion des Rezeptor-aktivierten Kanalstroms im Vergleich zur homomeren Expression zur Folge hatte. Weitere Experimente konnten dann zeigen, dass diese Effekte spezifisch für dieses Rezeptorheterodimer sind, und dass die Effekte von der Dosis bzw. dem Verhältnis der exprimierten cRNA abhängen. In Fluoreszenzmessung konnte zudem gezeigt werden, dass die Reduktion der Stromamplitude in der heterodimeren Expression nicht auf eine Reduktion von Kanalproteinen in der Zellmembran zurückzuführen ist. Zur weiteren Charakterisierung des bisher erst in Ansätzen erforschten 5-HT7 Rezeptors wurde dieser abschließend mit einem ß- adrenergen Rezeptor verglichen, der über den gleichen Signalweg bzw. Ionenkanal funktioniert. Auch hier zeigte sich eine signifikante Reduktion des Kanalstroms beim 5-HT7 Rezeptor. Die physiologische Relevanz dieser Ergebnisse liegt darin begründet, dass ein weiterführendes Verständnis von 5-HT Rezeptor vermittelten Signalwegen, insbesondere von der Bedeutung und den Mechanismen ihrer Heterodimersierung, neue pathophysiologische Zusammenhänge verdeutlicht. Speziell im Hinblick auf Erkrankungen, die mit den 5-HT Rezeptoren assoziiert sind, wie etwa Depressionen und Angststörungen, soll sich hieraus die Möglichkeit spezifischerer Therapien ergeben. / Heteromerisation of G-protein coupled receptors (GPCR)is a current object of research to find out diversity of signaling pathways. The functional details of those constructs in vivo are not yet understood, also molecular mechanisms. For the Serotonin receptors 1A and 7 heteromerisation recently could be shown, therefore intention now is to make a physiological characterization. By electrophysiological methods, i.e. voltage clamp, currents of potassium channels (Kir3 and TASK-1) could be detected using the heterologous expression system of oocytes of xenopus leavis. So we could demonstrate, that heterologous expression of both receptors leads to a reduced current amplitude in comparison to homologous expression of one receptor. Those effects where shown to be specific and dependend of cRNA dose. By using fluorescense tagged Kir-channel we could demonstrate that the effect doesn't base on less channel protein in cell surface of the oocytes. Another point of interest was the characterization of Serotonin-7 channel. Therefore we analyzed a dose-response-relationship, afterwards we compared data with a ß-adrenergic receptore in heteromeric expression with Serotonin-1A. The physiological relevance of those experiments is to understand serotonin pathways an metabolism that is very important in development of mental disorders of fear or major depression.
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The role of teacher support in the implementation of the Revised Curriculum statement, in grade 7 learning English in GautengStewart, Sandra Lilian 29 May 2008 (has links)
Abstract
When Curriculum 2005 was introduced into South African schools in 1998, it was
considered too cumbersome in design and its language too complex. In accordance
with the recommendations of the Ministerial Review Committee (2000) it was revised
into the Revised National Curriculum Statement (RNCS). The language was
simplified; it was streamlined to critical, developmental and learning outcomes and
assessment standards. Teachers were expected to produce these outcomes and
provision was to be made for improved teacher orientation and training, learning
support materials and provincial support to teachers in schools. The study looks at
how the RNCS is being provided for in terms of the support structures and
programmes available to teachers working in the Learning Area of English in Grade
Seven within the Senior Phase (Grades 7-9). Firstly, by identifying the competences
expected from teachers and secondly, by trying to establish the extent to which these
structures and programmes are effectively assisting teachers to achieve the required
competences and learning outcomes.
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Intramolecular Cycloaddition of Cyclobutadiene: Applications toward Functionalized 5-7-5 Tricyclic Ring Systems and Guaiane Natural ProductsHe, Jing January 2012 (has links)
Thesis advisor: Marc L. Snapper / Intramolecular cycloadditions of cyclobutadiene provide rapid access to rigid polycyclic systems with high strain energies and unique molecular geometries. Further functionalization of these systems followed by strain-release fragmentation provides great opportunities to construct fused-medium-ring architecture, which are very common in natural products but challenging to achieve efficiently. An intermolecular cyclopropanation/acid-mediated rearrangement strategy has been previously developed to access the 5-7 bicyclic ring systems in a highly stereospecific manner. The application of this strategy is being studied for the synthesis of a biologically interesting guaiane natural product: torilin. In a complementary fashion, an intramolecular cyclopropanation/thermal rearrangement sequence is developed to access two different molecular frameworks of 5-7-5 tricyclic ring systems. A library of functionalized 5-7-5 tricyclic ring systems can be systematically built up from the same starting material for potential future use in high-throughput screening. / Thesis (PhD) — Boston College, 2012. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
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Isomerisation and ring closing metathesis reactions towards benzo-fused heterocyclic compoundsAderibigbe, Blessing Atim 01 November 2006 (has links)
Student Number : 0410864E -
MSc dissertation -
School of Chemistry -
Faculty of Science / The aim of the project described in this dissertation is to explore the application of ring
closing metathesis (RCM) to the synthesis of 6-, 7-, 8- and 9-membered N,N-, N,O- and
O,O-benzo-fused heterocyclic compounds which are interesting structural motifs in
medicinal chemistry. In recent times, their structures have been widely used as molecular
scaffolds. Some of these heterocycles have been identified as antitumour agents,
antibiotics and anti-HIV agents.
In our laboratories, a variety of 6-, 7- and 8-membered nitrogen- and oxygen- containing
benzo-fused rings have been synthesized through ruthenium-mediated isomerisation and
RCM in moderate to good yields. The first step in the present project was N-protection of
suitable 2-aminophenols or o-phenylenediamines followed by allylation. Rutheniummediated
isomerisation followed by RCM was then used for the synthesis of the 6-
membered ring system tert-butyl 4H-1,4-benzoxazine-4-carboxylate 91 and the 7-
membered ring system tert-butyl 1,5-benzoxazepine-5(4H)-carboxylate 103 while only
RCM was used for the 8-membered ring systems, di(tert-butyl) 2,3,4,5-tetrahydro-1,6-
benzodiazocine-1,6-carboxylate 130, di(tert-butyl) 2,5-dihydro-1,6-benzodiazocine-1,6-
dicarboxylate 129, 1,6-dibenzoyl-1,2,5,6-tetrahydro-1,6-benzodiazocine 132, 7-methoxy-
2,5-dihydro-1,6-benzodioxocine 137 and the 9-membered ring system 1,6-bis[(4-
methylphenyl)sulfonyl]-2,5,6,7-tetrahydro-1H-1,6-benzodiazonine 159.
In the synthesis of the 7-membered ring systems, based on established methodology, we
encountered problems with the RCM from suitable benzylamine or benzyl alcohol
precursors. The reasons for this are not clear but we suspect this could be as a result of
electronic and kinetic factors. Nevertheless, we were able to synthesize a 7-membered
ring system, tert-butyl 1,5-benzoxazepine-5(4H)-carboxylate 103, from a readily
available precursor using a different methodology.
Approaches to the synthesis of the 8-membered ring systems, di(tert-butyl) 2,3,4,5-
tetrahydro-1,6-benzodiazocine-1,6-carboxylate 130, di(tert-butyl) 2,5-dihydro-1,6-
benzodiazocine-1,6-dicarboxylate 129, 1,6-dibenzoyl-1,2,5,6-tetrahydro-1,6-
benzodiazocine 132 and 7-methoxy-2,5-dihydro-1,6-benzodioxocine 137, as described in
this dissertation, made extensive use of RCM in moderate to good yields, but the
deprotection of the Boc group after hydrogenation proved to be a problem.
The synthesis of the 9-membered nitrogen containing benzo-fused compounds, 1,6-
bis[(4-methylphenyl)sulfonyl]-2,5,6,7-tetrahydro-1H-1,6-benzodiazonine 159 by RCM
was successful but in the synthesis of the N,O-benzo-fused compound by RCM, we
suspect that polymerization, which is a side reaction in RCM reactions that are slow,
occurred. In the synthesis of the 9-membered O,O-benzo-fused compounds, we only
isolated the starting material.
The final approach in this dissertation involved the use of ruthenium-mediated
isomerisation to afford internal isomerisation of the double bond within the heterocyclic
rings of the 8-membered and 9-membered benzo-fused compounds previously prepared
in our laboratory. This gave a mixture of regioisomers of 10-methoxy-2,3-dihydro-1,6-
benzodioxocine 163 and 7-methoxy-2,3-dihydro-1,6-benzodiazocine 164, 1,6-bis[(4-
Methylphenyl)sulfonyl]-1,2,3,6-tetrahydro-1,6-benzodiazocine 166, a regioisomeric
mixture of 6-[(4-methylphenyl)sulfonyl]-3,6-dihydro-2H-1,6,-benzoxazocine 161 and
6-[(4-methylphenyl)sulfonyl]-5,6-dihydro-4H-1,6,-benzoxazocine 162, and the 9-
membered benzo-fused ring system, 1,6-bis[(4-methylphenyl)sulfonyl]-2,3,6,7-
tetrahydro-1H-1,6-benzodiazonine 170. The yields were good and the solid state
structures of these isomerised compounds were examined by X-ray crystallography. Xray
diffraction was also performed on the solid state 8- and 9-membered benzo-fused ring
systems. We also compared the crystal structures of the 8- and 9-membered benzo-fused
compounds with their isomerised compounds.
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