No description available.

No description available.

Legionella pneumophila, an intracellular pathogen of protozoa, is well known for its dimorphic life cycle that alternates between the vegetative replicative form (RF) and highly infectious cyst-like form (CLF). To this date several virulence factors including LpRpoS, LpIHF, and the Dot/Icm secretion system have been found to be required for the survival of L. pneumophila in macrophage and protozoa. Here we have identified and characterised Lpg1967, an orthologue of Pseudomonas PsrA in L. pneumophila. PsrA (Lpg1967) was found to regulate the expression of previously known virulence factors such non-coding RNAs, RsmY/Z, RpoS, LpIHF, flagella and Dot/Icm Type IV secretion system. In addition, the ΔpsrA mutant strain was unable to establish Legionella-containing vacuole and thus displayed a severe growth defect in the U937 derived macrophage cell line. Thus, PsrA was found to play an important role in controlling the regulatory cascade governing virulence in L. pneumophila. / October 2014

Teotihuacan was the most influential city in the Classic Mesoamerican worldsystem. Like other influential cities in the ancient world, however, Teotihuacan did not homogenously affect the various cultural landscapes that thrived in Mesoamerica during the Classic period (300-900 CE). Even where strong central Mexican influences appear outside the Basin of Mexico, the nature, extent, and strength of these influences are discontinuous over time and space. Every place within the Classic Mesoamerican landscape has a unique Teotihuacan story. In the Tuxtla Mountains of southern Veracruz, Mexico, Matacapan, located in the Catemaco Valley, drew heavily upon ideas and symbols fostered at Teotihuacan, while Totocapan, a peer political capital located in the neighboring Tepango Valley, emphasized social institutions well-entrenched within Gulf Coast cultural traditions. Through a detailed comparison of these two river valleys, I demonstrate that each polity developed along different trajectories. By the Middle Classic (450-650 CE) each polity displayed different political, economic, and ritual institutions. While they shared an underlying material culture style, the data suggest that the regimes of both polities promoted a different ideology. These cultural divergences did not, however, cause hostilities between them. To the contrary, compositional sourcing of Coarse Orange jars indicates that they engaged in material exchanges with each other. Agents at each settlement within the study region made unique decisions with regard to their involvement in local, regional, and macroregional interaction networks, particularly with regard to the adoption or rejection of Teotihuacan cultural elements. As a result, the Classic period Tuxtlas comprised multiple overlapping, but disjoint, landscapes of interaction. Places of human settlement were nodes on the landscape where these disjoint landscapes intersected in space and time. By examining these disjunctures, world-system studies can reveal a trend of increasing cultural diversity that parallels the better-theorized trend of homogenization emphasized by core-periphery models. In this dissertation, I take the initial steps toward developing an archaeology of disjuncture that examines the cultural variability that develops where groups across the landscape employ different strategies of interaction within the world-system.

No description available.

The eukaryotic nuclear envelope (NE), separates the nucleoplasm from cytoplasm and is made up of two concentric lipid membranes, the outer and the inner nuclear membranes (ONM and INM), the nuclear pore complexes (NPCs) and an underlying filamentous nuclear lamina. The INM contains hundreds of unique transmembrane proteins of which only a handful have been characterized. In this thesis, I aimed to understand the functional organization of proteins in the nuclear envelope and I focused on investigating the functions of a recently identified INM transmembrane protein, Samp1. We have developed a novel and robust approach, MCLIP, to identify specific protein-protein interactions taking place in live cells. Using MCLIP, we have shown that Samp1 interacts with proteins of the LINC complex, the nuclear lamina and components of the mitotic spindle. Samp1's specific interactions with a variety of binding partners, suggest that Samp1 plays important roles both in interphase and in mitosis.  We have also shown that Samp1 can provide a binding site at the INM for the GTPase Ran, a master regulator of protein interactions in interphase and in mitosis. Furthermore, we have also investigated the role of Samp1 in cell differentiation using two independent model systems. In human iPSCs, ectopic expression of Samp1 promoted differentiation despite pluripotent culture conditions. In C2C12 myoblast, depletion of Samp1 completely blocked differentiation into myotubes. The two studies complement each other and suggest that Samp1 has a strong differentiation promoting activity. Taken together, the findings in this thesis, give insights on the unexpected and unforeseen roles played by a transmembrane protein in different fundamental cellular process. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript.</p>

Cette thèse propose une approche rationnelle pour le design de polymères à empreintes moléculaires (MIPs) pour la détection de nitro-explosifs. Les polymères à empreintes moléculaires qui miment la reconnaissance moléculaire biologique, ont l’avantage d’être stables dans des environnements sévères et peuvent adopter différentes formes physiques pour le couplage avec des transducteurs. Leur synthèse est basée sur la co-polymérisation de monomères fonctionnels et réticulants en présence de la molécule cible, ou comme dans cette thèse, d’un analogue ayant une structure proche de celle de la molécule cible. Cela conduit à la formation d’un réseau polymérique tridimensionnel rigide avec des sites de liaison complémentaires en taille, forme et position des groupes fonctionnels de la molécule cible ou de l’analogue. Pour identifier le meilleur monomère fonctionnel pour notre molécule cible, une approche rationnelle basée sur la modélisation moléculaire, la résonance magnétique nucléaire (RMN) et le titrage par calorimétrie isotherme (ITC) a été utilisée. Elle permet d’optimiser le mélange de pré-polymérisation pour identifier le monomère fonctionnel interagissant le plus fortement avec la molécule cible. Les résultats obtenus ont été confrontés à des études de liaison à partir de polymères synthétisés. La formulation polymérique ainsi conçue est intégrée aux surfaces du transducteur sous forme de nanoparticules, de films et de nanoparticules incorporés dans des films de polydopamine électropolymérisés. En plus des polymères traditionnels obtenus par polymérisation radicalaire classique sous forme de particules, des films de MIP à base de polydopamine électropolymérisés ont été étudiés en tant qu'approche alternative pour la détection électrochimique de nitro-explosifs. / This thesis proposes a rational design approach towards molecularly imprinted polymers (MIPs) for sensing nitro-explosives. Molecularly imprinted polymers are mimicking biological molecular recognition. They have the advantage to be stable in harsh environments and can be tailored into different physical forms for interfacing with transducers. Their synthesis is based on the co-polymerization of functional and cross-linking monomers in the presence of the target analyte or, as in this thesis, with a structural analogue leading to a rigid three-dimensional polymer network with binding sites complementary to the template in size, shape and position of the functional groups. The choice of the functional monomer was carried out with a rational design approach combining molecular modelling, nuclear magnetic resonance (NMR) and isothermal calorimetry (ITC) studies. This allows to optimize the pre-polymerization mixture in order to get strong complexation between the functional monomer and the template. The obtained results were confronted with binding studies performed on synthesized polymers. The thus designed polymer formulation was interfaced with transducer surfaces in form of nanoparticles, films and nanoparticles embedded into electro-polymerized polydopamine films. In addition to the traditional MIPs by free radical polymerization, molecularly imprinted in-situ electro-polymerized polydopamine films were investigated as an alternative approach for sensing nitro-explosives electrochemically.

<p>An introduction to bacterial polysaccharides and the methods for structural determination are described in the first two parts of the thesis.</p><p>In a structural elucidation of bacterial polysaccharides NMR experiments are important as is component analysis. A short description of immunochemical methods such as enzyme immunoassays is included. Two NMR techniques used for interaction studies, trNOE and STD NMR, are also discussed. </p><p>The third part of the thesis discusses and summarizes the results from the included papers. The structures of the exopolysaccharides produced by two lactic acid bacteria are determined by one- and two dimensional NMR experiments. One is a heteropolysaccharide produced by <i>Streptococcus thermophilus</i> and the other a homopolysaccharide produced by <i>Propionibacterium freudenreichii</i>. The structure of an acidic polysaccharide from a marine bacterium with two serine residues in the repeating unit is also investigated. The structural and immunological relationship between two O-antigenic polysaccharides from <i>Escherichia coli</i> strain 180/C3 and O5 is discussed and investigated. Finally, interaction studies of an octasaccharide derived from the <i>Salmonella enteritidis</i> O-antigen and a bacteriophage are described which were performed with NMR experiments.</p>

An introduction to bacterial polysaccharides and the methods for structural determination are described in the first two parts of the thesis. In a structural elucidation of bacterial polysaccharides NMR experiments are important as is component analysis. A short description of immunochemical methods such as enzyme immunoassays is included. Two NMR techniques used for interaction studies, trNOE and STD NMR, are also discussed. The third part of the thesis discusses and summarizes the results from the included papers. The structures of the exopolysaccharides produced by two lactic acid bacteria are determined by one- and two dimensional NMR experiments. One is a heteropolysaccharide produced by Streptococcus thermophilus and the other a homopolysaccharide produced by Propionibacterium freudenreichii. The structure of an acidic polysaccharide from a marine bacterium with two serine residues in the repeating unit is also investigated. The structural and immunological relationship between two O-antigenic polysaccharides from Escherichia coli strain 180/C3 and O5 is discussed and investigated. Finally, interaction studies of an octasaccharide derived from the Salmonella enteritidis O-antigen and a bacteriophage are described which were performed with NMR experiments.

No description available.