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Université de Lausanne

Théorie bayesienne de la décision statistique et mesure de la radioactivité

Laedermann, Jean-Pascal ; Valley, Jean-François (Dir.)

Thèse de doctorat : Université de Lausanne : 2003.

L'objet de ce travail est l'évaluation de l'activité de radionucléides présents à l'état de traces, par exemple dans l'environnement. Lorsque les mesures sont de courte durée, ou si les sources sont peu actives, l'analyse statistique standard ne donne plus une estimation fiable de l'activité et de son incertitude. L'introduction du concept bayesien d'a priori permet de modéliser...

Université de Lausanne

Organisation of genetic variation in multinucleate arbuscular mycorrhizal fungi

Kuhn, Gerrit ; Sanders, Ian R. (Dir.)

Thèse de doctorat : Université de Lausanne : 2003.

Arbuscular mycorrhizal fungi (AMF) are root symbionts with about 80% of all known species of vascular land plants. AMF are ecologically important because of the benefits that they confer to plants. Molecular studies on AMF showed that rDNA sequences were highly variable between species and within species. Because AMF are coenocytic and multinucleate there are several possibilities how this...

Université de Lausanne

Linking landscape- and population ecology for large population management modelling: the case of Ibex (capra ibex) in Switzerland

Hirzel, Alexandre ; Perrin, Nicolas (Dir.)

Thèse de doctorat : Université de Lausanne : 2001.

Conservation biology is commonly associated to small and endangered population protection. Nevertheless, large or potentially large populations may also need human management to prevent negative effects of overpopulation. As there are both qualitative and quantitative differences between small population protection and large population controlling, distinct methods and models are needed. The aim...

Université de Lausanne

Etude systématique, cladistique et biogéographique des Baetidae (Ephemeroptera) de Madagascar

Gattoliat, Jean-Luc ; Sartori, Michel (Dir.)

Thèse de doctorat : Université de Lausanne : 2002.

Mayflies (Ephemeroptera) are among the oldest known flying insects and encompass a very small number of species (ca 2500 species). Larvae are strictly freshwater inhabitants; this stage lasts generally one year. The imaginal stage is extremely short, from few hours to few days, and is devoted almost entirely to reproduction. Madagascar is the fourth largest island in the world by area. It is...

Université de Lausanne

Contribution to the Development of the LHCb Vertex Locator Readout Electronics

Ermoline, Iouri ; Bay, Aurélio (Dir.)

Thèse de doctorat : Université de Lausanne : 2003.

The LHCb experiment is being built at the future LHC accelerator at CERN. It is a forward single-arm spectrometer dedicated to precision measurements of CP violation and rare decays in the b quark sector. Presently it is finishing its R

Université de Lausanne

Cryo-negative staining: advantages and applications for three-dimensional electron microscopy of biological macromolecules

De Carlo, Sacha ; Dubochet, Jacques (Dir.)

Thèse de doctorat : Université de Lausanne : 2002.

Many biological specimens do not arrange themselves in ordered assemblies (tubular or flat 2D crystals) suitable for electron crystallography, nor in perfectly ordered 3D crystals for X-ray diffraction; many other are simply too large to be approached by NMR spectroscopy. Therefore, single-particles analysis has become a progressively more important technique for structural determination of large...

Université de Lausanne

Phytochemical investigation of plants used in African traditional medicine: "Dioscorea sylvatica" (Dioscoreaceae), "Urginea altissima" (Liliaceae), "Jamesbrittenia fodina" and "Jamesbrittenia elegantissima" (Scrophulariaceae)

Cogne, Anne-Laure ; Hostettmann, Kurt (Dir.)

Thèse de doctorat : Université de Lausanne : 2002.

In certain African countries, medicinal plants represent the unique source of to 90% of the population. The knowledge of traditional healers represents a basis for the pharmacological and phytochemical investigation of these natural medicines. This work first focused on the validation of use of two plants frequently employed in traditional medicine, Dioscorea sylvatica (Dioscoreaceae) and Urginea...

Université de Lausanne

Integral cohomology of finite postnikov towers

Clément, Alain ; Arlettaz, Dominique (Dir.)

Thèse de doctorat : Université de Lausanne : 2002.

By the work of H. Cartan, it is well known that one can find elements of arbitrarilly high torsion in the integral (co)homology groups of an Eilenberg-MacLane space K(G,n), where G is a non-trivial abelian group and n>1. The main goal of this work is to extend this result to H-spaces having more than one non-trivial homotopy groups. In order to have an accurate hold on H. Cartan's result, we...

Université de Lausanne

Impact des maladies rhumatismales sur la population âgée en Suisse et sa consommation de soins

Mariller, Marjorie ; Santos-Eggimann, B. (Dir.)

Thèse de doctorat : Université de Lausanne : 2002.

Rheumatic diseases are frequently observed in elderly people and have an important impact on tlieir life qurlity. There are fe1.v Swiss stuciies on the epiciemio!ogica! situttien and on the impact of such diseases on the use of health services. This thesis aims at studying the current knowledge based on Swiss and international literature and at establishing the situation in Switzerland from a...