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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Role of cholesterol and N-glycosylation in apical sorting of GPI- APs in polarized epithelial FRT cells / Rôle du cholestérol et de la N-glycosylation dans le tri apical de GPI-APs dans les cellules polarisées épithéliales FRT

Imjeti, Naga Sailaja 01 July 2011 (has links)
Les cellules épithéliales sont capable de se polariser avec un domaine apical et un basolatéral qui diffèrent nettement en leurs protéines, leurs composition en lipides et donc en fonction. Cette asymétrie reflète la capacité des cellules épithéliales à affecter les protéines nouvellement synthétisées et les lipides à chacune des surfaces de la cellule. Alors que les signaux responsables pour la sélection basolatérale des protéines ont été clairement identifiés, la situation en ce qui concerne la sélection apicale des protéines demeure mal comprise. Nous avons précédemment montré que contrairement aux GPI-APs basolatérales l’oligoisomérisation des protéines ancrées glycosylphosphatidylinositol (GPI-AP) dans l'appareil de Golgi est requise pour le tri apical. Il est intéressent de noter que ce mécanisme est conservé dans deux types de cellules épithéliales, les cellules MDCK et les cellules FRT, qui présentent des différences de tri des GPI-APs. Cependant, le mécanisme précis menant à cet événement n'est pas compris. Nos données précédentes ont démontré que le simple ajout de cholestérol aux cellules MDCK est nécessaire et suffisant pour induire l'oligomérisation et le tri apical d'une GPI-AP basolatérale. Alors que dans l’étude présente sur les cellules FRT, nous avons montré que contrairement aux cellules MDCK, le cholestérol ne joue pas un rôle majeur dans la régulation du tri apicale des GPI-APs. De plus, nous avons également montré que les GPI-APs apicales et basolatérales ne sont pas séparées dans le Golgi en fonction de leur teneur en cholestérol entourant l'environnement membranaire. Par ailleurs, nous avon démontré que la N-glycosylation des protéines de l’ectodomaine est indispensable à l’oligomérisation et au tri apical de GPI-APS. Nos données indiquent qu’il existe au moins deux mécanismes, l’un dépendant du taux de cholestérol et l’autre de la N-glycosylation, qui déterminent l’oligomérisation dans l'appareil de Golgi et le tri des GPI-APs vers la membrane apicale. / Epithelial cells represent the ability to polarize with an apical and basolateral domains which differ markedly in proteins, lipid composition and therefore in function. This asymmetry reflects the ability of epithelial cells to sort newly synthesized proteins and lipid to either cell surface. While the signals responsible for basolateral targeting of the proteins have been clearly understood, the situation regarding the apical sorting of proteins is more obscure. We have previously shown that differently from basolateral GPI-APs oligomerization in the Golgi apparatus is necessary for apical sorting of Glycosylphosphatidylinositol- anchored proteins (GPI-APs). Interestingly this mechanism is conserved in two different kinds of epithelial cells, MDCK and FRT cells, which exhibits a difference in the sorting of GPI-APs. However the precise mechanism leading to this event is not understood. Our previous data demonstrated that simple addition of cholesterol to MDCK cells is necessary and sufficient to induce the oligomerization and apical sorting of a basolateral GPI-AP. Whereas, in this present study in FRT cells we showed that in contrast with MDCK cells cholesterol is not an active player in the regulation of GPI- APs apical sorting. In addition, we also showed that apical and basolateral GPI-APs are not segregated in the Golgi on the bases of the cholesterol content of the surrounding membrane environment. Furthermore, we demonstrated that N- glycosylation of the protein ectodomain is critical for oligomerization and apical sorting of GPI-APs. Our data indicates that at least two mechanisms depending either on cholesterol or on N-glycosylation exist to determine oligomerization in the Golgi and sorting to the apical membrane of GPI-APs.
12

Thermisches Spritzen mit wasserbasierten Suspensionen —

Trache, Richard 24 April 2018 (has links) (PDF)
Das thermische Spritzen ist ein industrieller Beschichtungsprozess, der hauptsächlich zum Schutz oder zur Funktionalisierung von Bauteiloberflächen eingesetzt wird. In der Regel werden mit diesem Verfahren Schichten mit einer Dicke von 50 bis zu einigen 100 Mikrometern aufgetragen, die überwiegend durch mechanische Verklammerung haften, wodurch die Materialeigenschaften des Bauteils weitgehend erhalten bleiben. Mit der Einführung von Suspensionen als neue Kategorie der Spritzzusätze etabliert sich gerade eine der weitreichendsten Innovationen der letzten Jahre auf dem Gebiet des thermischen Spritzens. Suspensionen sind Stoffgemische, die aus einer feindispersen, festen Phase, dem Schichtwerkstoff, und einer flüssigen Phase als Trägermedium bestehen. Damit können Partikel mit geringerer Größe in den Beschichtungsprozess eingebracht werden, so dass sich dünnere Schichten und feinere Mikrostrukturen realisieren lassen. Das thermische Spritzen mit Suspensionen erweitert damit den Anwendungsbereich und bildet eine Brückentechnologie zu den Vakuum- Dünnschichtverfahren. Im Fokus dieser Arbeit stehen die drei wichtigen keramischen Werkstoffe Aluminiumoxid, Chromoxid und yttriumstabilisiertes Zirkonoxid, die in der Form von wasserbasierten Suspensionen als Spritzzusätze für das Atmosphärische Plasmaspritzen (APS) und das Hochgeschwindigkeitsflammspritzen (HVOF) verwendet werden. Für die Injektion der Suspension in das Plasma oder die Flamme wird ein automatisiertes Suspensionsfördersystem verwendet. Darüber hinaus werden spezielle mehrteilige Injektoren entwickelt und getestet. Es werden neue Erkenntnisse zur statistischen Auswertung der Zusammenhänge zwischen den Injektionsparametern, den messbaren Eigenschaften der Tropfenwolke während der Zerstäubung, den Partikeleigenschaften im Spritzstrahl und den daraus resultierenden Schichteigenschaften vorgestellt. Dafür wurde eine neue Kenngröße für den Beschichtungserfolg, ein sogenannter Beschichtungsfaktor, hergeleitet, der sich mit vergleichsweise geringem Aufwand bestimmen lässt und außerdem die zusätzlichen Prozessvariablen beim Suspensionsspritzen mit berücksichtigt. Im Anschluss werden Beispiele für wasserbasierte, suspensionsgespritzte Schichten aus den drei keramischen Werkstoffen vorgestellt, bei denen durch entsprechende Charakterisierungsmethoden das Anwendungspotential im Vergleich zu Spritzschichten nach dem Stand der Technik verdeutlicht wird. Die Anwendungsgebiete umfassen dabei die elektrische Isolation, den Verschleißschutz sowie die thermische Isolation. Den Abschluss der Arbeit bildet eine kritische Diskussion der Eignung von wasserbasierten Suspensionen für das thermische Spritzen mit Plasma- und Flammspritzprozessen. Es werden die Vor- und Nachteile dieser Beschichtungstechnik analysiert und Verbesserungsvorschläge sowohl für die weitere Suspensions- als auch für die Anlagenentwicklung unterbreitet.
13

The shifting metropolitan geographies of advanced producer services: Agglomeration processes, professional networks and corporate restructuring in world city Brussels / L'évolution des géographies métropolitaines des services avancés à la production: Processus d'agglomération, réseaux professionnels et restructuration des entreprises dans la ville mondiale de Bruxelles

Waiengnier, Maëlys 01 February 2021 (has links) (PDF)
Les services avancés à la production (APS) dans les domaines de la comptabilité, de la publicité, de la finance, des services juridiques et du conseil en gestion, ainsi que de l'informatique aident leurs clients à développer des stratégies d'accumulation financière et assurent la coordination et la gouvernance des réseaux de production mondiaux. Néanmoins, alors que les réseaux mondiaux ont été richement documentés par la recherche sur les villes mondiales, cette thèse tente de comprendre les processus moins étudiés qui structurent la géographie des APS dans la ville mondiale de Bruxelles. Pour ce faire, je réexamine deux hypothèses qui restent peu étudiées et implicites. D'une part, il est supposé que les firmes APS s'agglomèrent et constituent des réseaux de collaboration de firmes APS au sein des villes, un complexe APS. D'autre part, alors que les réseaux mondiaux de firmes APS ont été minutieusement documentés, le rôle de commandement et de contrôle attribué aux villes mondiales reste souvent supposé découler directement de ces réseaux. Pour explorer ces hypothèses, j'ai développé trois types d'analyses appliqués au cas de Bruxelles, une ville dont l'internationalisation est basée sur sa fonction politique et sa forte insertion dans les réseaux APS :une analyse géographique des processus d’agglomération des APS, une enquête auprès des professionnels APS pour caractériser les interactions au sein et entre les secteurs APS et une étude de cas sur les collaborations concrètes entre les entreprises APS dans le cas de processus de restructurations bancaires. Les résultats conjoints des trois analyses m'amènent à soutenir que la notion de complexe APS doit être nuancée avec l'idée que la finance fonctionne comme l'élément central dans les relations entre les APS avec des secteurs auxiliaires autour de la finance. Comme cette explication n'éclaire pas complètement la notion de contrôle et de commandement de l'économie, je recommande de prendre en compte la recherche constante de la rentabilité qui fait pression sur l'organisation des entreprises. Je plaide donc pour une meilleure articulation entre les réseaux mondiaux des APS et le capitalisme financiarisé. Pour conclure, je montre que Bruxelles occupe une position intermédiaire dans la division internationale du travail et que ce rôle se limite de plus en plus à la seule coordination du marché national. / Option Géographie du Doctorat en Sciences / info:eu-repo/semantics/nonPublished
14

Obrobitelné biokeramiky připravené metodou gelového lití / Machinable bioceramics prepared by gelcasting method

Kolář, Martin January 2013 (has links)
In the diploma thesis, overviews of the existing literature focused on the gelcasting method and based on the findings were prepared aqueous slurries of zirconium oxide for gelcasting method. These suspensions were examined for the influence of the content ceramics powder, type and content of dispersants and volume of initiator on viscosity of aqueous suspensions and process of polymerization. Optimum ceramic suspension had 45 vol.% of ceramic powder which was stabilized by 0,5 weight % of dispersant Dolapix CE 64. Polymerization running at room temperature was initiated by 0,175 weight % of ammonium persufate without accelerator. Microstructure of prepared ceramic blanks and sintered bodies was compared with body prepared by isostatic pressing. For the machining tests were prepared blanks in disc-shaped.
15

Analogues of eta invariants for even dimensional manifolds

Xie, Zhizhang 27 July 2011 (has links)
No description available.
16

Protective coatings for Al press tools used in automotive industry / Protective coatings for Al press tools used in automotive industry

Tan, Ruoyo January 2014 (has links)
The application of the thermally sprayed WC-Co and Cr 3C2-NiCr coatings have been widely used in industry for its superior sliding, abrasive and erosive wear properties. The Al2O3 coating possessing high hardness can be utilized to improve the wear resistance of the metallic surface. Replacing the stamping tool material from steel to lightweight aluminium with protective coatings offers significant gains such as reduction in power costs and increasing operational efficiency during manufacturing of sheet automobile parts. In this study, the WC-CoCr and Cr3C2-NiCr coatings were sprayed with High Velocity Air-Fuel (HVAF) process and Al2O3 coating was deposited using Atmosphere Plasma Spraying (APS) process. The coatings were evaluated and compared based on the results of roughness tests, hardness tests, adhesion tests, quantitative imaging analysis and microstructure analysis. The experimental results revealed that the roughness value varied in a lower range which implies of a high density of the coatings. It was found that coatings have an extremely high hardness value as tested by the Vickers hardness test. The WC-Co coating was found to be the hardest (1215.2HV). The adhesion test was implemented according to the ASTM C633-79 standard. The result showed that WC-Co and Cr3C2-NiCr coatings without a bond coat had high tensile strength, higher than the respective glue strength (63.54MPa, 75.89MPa). Whereas, the Al2O3 coating has a much lower tensile strength (15.2MPa, 25.68MPa, with and without bond) than others and using a bond coat layer does not contribute to an increase in adhesion strength of the cermet coatings. The coating thickness was evaluated using Light Optical Microscopy (LOM) and microstructure analysis was carried out using Scanning Electron Microscopy (SEM). From the microstructure analysis, it was observed that all the coatings have a dense microstructure, very low porosity and low oxide inclusions in top coat. The WC and Cr3C2 grains retain a large volume fraction of finely dispersed in matrix. The alumina coating was found to have low levels of un-melted or the re-solidified particles in the coating. All of the aforementioned analysis and results reveal that WC/CoCr and Cr3C2-NiCr coating show promising potential for press tool applications. However, abrasive resistance test still remained to be done and will be performed in the future. The result of it can reveal the actual wear resistance between two coatings in reality and will be helpful in determining the better protective coating for aluminium press tools
17

Approaches to the development of human resources management competency standards in the Australian Public Service

McNeill, Matthew, n/a January 1996 (has links)
This thesis is derived from a work project, the consideration of approaches to the development of Human Resource Management competency standards for the Australian Public Service. The thesis is a vehicle for examining and exploring a complex Human Resource Development strategy, through dealing with the details of the project. This project was undertaken from 16 January to 13 April 1995. The project occurred in a turbulent environment with limited resources. The decision whether or not to develop Human Resource Management competencies was an important step in the implementation of the National Training Reform Agenda by the Australian Public Service, being influenced by a number of changes in the national environment as well as having to accommodate a number of factors internal to the Australian Public Service. Factors included: the impact of changes to vocational education and training at the national level such as the introduction of the Australian Qualifications Framework; the impact of a devolved management structure; the differing needs of stakeholders; the need to accommodate industrial relations issues; and the impact of resource constraints (including time). The thesis explains the context and conduct of the project. It critically examines the development of action plans and progress made over the course of the project. It explains the process and content of project activities and provides comments on them. This allows insights into the development of Human Resource Development policy in the public sector. In particular it shows how the nature of the project changed from its anticipated focus on competency identification to its final focus on preparing advice to the Joint Australian Public Service Training Council. That advice recommended that separate Human Resource Management competency standards should not, after all, be identified. It concluded that they should be integrated with the core competency standards for the Australian Public Service. The thesis reflects on key aspects of the project including its subject matter, processes, and outcomes. Some of these concern the impact of the systemic, conceptual and structural changes in the National Training Reform Agenda on strategic Human Resource Development. In addition the thesis reflects on the many roles of the project officer in strategic Human Resource Development activities, suggesting that the project officer should act as a consultant rather than servant. To illustrate this point the thesis describes how the project officer was able to facilitate processes during this project that resulted in management accepting outcomes that differed from their expectations but better met their needs. The work of Lippitt and Lippitt (1986) is found to be helpful in identifying the project officer's roles. Finally the thesis considers the outcomes of the project in the light of the publication of the Karpin report (1995) and finds that the outcome is consistent with the thrust of that report.
18

Strategic human resource management : matching the reality to the rhetoric in the Australian Public Service

Simpson, Beverley, n/a January 2000 (has links)
This paper focuses on three main themes. Firstly, what is Strategic Human Resource Management (SHRM) and the rhetoric surrounding it? Secondly, does the reality match the rhetoric? Thirdly, is the model that has been adopted by the private sector an appropriate model for the Australian public sector to be using? HR has been criticised for being an administrative function that is regulatory and compliance based, adding little value to an organisation. SHRM provides a strategic focus, involving the partnering of HR and line areas to provide value added people services. SHRM has been described by some theorists (Ulrich, Rothwell et al) as the only way of the future for the HR function. The model/s of SHRM that have been adopted by the private sector are now being promoted by the Public Service and Merit Protection Commission as the way forward for HR in the Australian Public Service. This paper discusses the appropriateness of the SHRM model/s for the public sector by examining what is happening in the HR area in three Commonwealth Government departments: Health and Aged Care, Transport and Regional Services and Family and Community Services. It examines the dilemmas for the HR functions as they try to move to an SHRM approach in these organisations, and suggests models that are appropriate to the public sector context.
19

Scenario planning in Australian government

Thomson, Nicolas Maxwell, n/a January 2006 (has links)
Is scenario planning a process that can be used by agencies of the Australian Public Service to generate and develop information that is relevant to the future, and thereby make possible improved strategic planning? This is the core question of this dissertation. The first part of the thesis is devoted to the case for investigating the benefits of scenario planning. Literature defining and describing the benefits of scenario planning for both private and public sector organisations is examined, and factors that appear to be critical to effective implementation of the process are discussed. Against this theoretical background the empirical evidence of seven cases of the application of scenario planning in six agencies of the Australian Public Service is considered. Several conclusions are drawn on the basis of the data obtained from the seven cases studied. Scenario planning is more likely to make possible improved strategic planning of public sector agencies such as those that comprise the Australian Public Service (irrespective of their function or size) if it has the active involvement of senior management during the developmental phase of the process, and their ongoing support for any follow-up activity. In addition, a well resourced and in-depth research phase is integral to the success of the process. Even if these elements are not present to a high degree, a well managed scenario planning exercise will improve to some degree the ability of an agency�s senior executive to think more openly and proactively about its future business context. In addition, well resourced and properly supported scenario planning can also help a public sector agency to improve the quality of its information gathering, test the viability of its strategy options and develop appropriate contingency plans.
20

Laser Scattering as a Tool to Determine the Effect of Temperature on Diatom Aggregation

Rzadkowolski, Charles Edward 2010 August 1900 (has links)
Diatoms are estimated to contribute 25 percent of the primary production on Earth and therefore they play a significant role in the global carbon cycle. Diatom blooms often terminate with the formation of aggregates that sink rapidly from surface waters, affecting the flux of organic carbon from the surface to deep waters and the sea floor. The role of carbon-rich transparent exopolymeric particles (TEP) in aggregate formation as ocean temperature increases has yet to investigated in continuous cultures. I hypothesize that temperature increase can influence the production of TEP, a fraction of total suspended exopolymers. To test the hypothesis, a laser in situ scattering and transmissometry instrument (LISST-100X, Sequoia Instruments) successfully counted and sized six individual diatom species in batch culture: Chaetoceros muelleri, Coscinodiscus wailesii, Thalassiosira weissflogii, Phaeodactylum tricornutum, Skeletonema costatum, and Skeletonema marinoi and successfully demonstrated its efficacy in detecting diatom aggregates using S. costatum. Four replicate continuous cultures were sampled for particle size distribution (PSD), nutrients, chlorophyll a, total carbohydrates, prokaryote concentration, and TEP at temperatures of 22.5, 27 and then 20 degrees C. While TEP particles were scarce, acid polysaccharide (APS)-coated C. muelleri cells were observed, forming dense webs on the filters. Both carbohydrate per cell and APS area per cell were found to significantly correlate with temperature (p<0.05) while significant difference between APS concentration at each temperature was only found between 27 and 22.5 or 20 degrees C (p<0.05). Net changes in PSDs with increasing temperature showed that distributions of relative volume concentration decreased in the smallest size bins and increased in the largest size bins. Our results show that increasing the temperatures of nitrogen-limited C. muelleri cultures did not cause increased TEP formation but instead resulted in increased cell-surface coating. Increasing concentration of cell coatings and TEP particles will cause diatoms to aggregate more readily, enhancing their sinking rate away from the ocean surface. Increased ocean temperature has great implications for diatom blooms and other microorganisms, causing greater export of carbon out of the surface waters and potentially altering the microbial loop.

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