No description available.

Although its use has become more widespread, controlled low-strength material, or CLSM, has fallen through the crack between geotechnical engineering and materials engineering research. The National Ready Mix Association states that CLSM is not a low strength concrete, and geotechnical engineers do not consider it as a conventional aggregate backfill. The use of CLSM as a bridge abutment backfill material brings up the need to understand the passive force versus backwall displacement relationship for this application. To safely account for forces generated due to seismic activity and thermal expansion in bridge design, it is important to understand the passive force versus backwall displacement relationship. Previous researchers have pointed out the fallacy of designing skewed bridges the same as non-skewed bridges. They observed that as the bridge skew angle increases, the peak passive force is significantly diminished which could lead to poor or even unsafe performance. The literature agrees that a displacement of 3-5% of the wall height is required to mobilize the peak passive resistance. The shape of the passive force displacement curve is best represented as hyperbolic in shape, and the Log Spiral method has been confirmed to be the most accurate at predicting the peak passive force and the shape of the failure plane. All of the previous research on this topic, whether full-scale field tests or large-scale laboratory tests, has been done with dense compacted sand, dense granular backfill, or computer modeling of these types of conventional backfill materials. However, the use of CLSM is increasing because of the product's satisfactory performance as a conventional backfill replacement and the time saving, or economic, benefits. To determine the relationship of passive force versus backwall displacement for a CLSM backfilled bridge abutment, two laboratory large-scale lateral load tests were conducted at skew angles of 0 and 30°. The model backwall was a 4.13 ft (1.26 m) wide and 2 ft (0.61 m) tall reinforced concrete block skewed to either 0 or 30°. The passive force-displacement curves for the two tests were hyperbolic in shape, and the displacement required to reach the peak passive resistance was approximately 0.75-2% of the wall height. The effect of skew angle on the magnitude of passive resistance in the CLSM backfill was much less significant than for conventional backfill materials. However, within displacements of 4-5% of the backwall height, the passive force-displacement curve reached a relatively constant residual or ultimate strength. The residual strength ranged from 20-40% of the measured peak passive resistance. The failure plane did not follow the logarithmic spiral pattern as the conventional backfill materials did. Instead, the failure plane was nearly linear and the failed wedge was displaced more like a block with very low compressive strains.

Controlled Low Strength Materials (CLSM) are cementitious self-compacting materials, comprised of low cement content, supplementary cementing materials, fine aggregates, and water. CLSM is typically used as an alternative to conventional compacted granular backfill in applications, such as pavement bases, erosion control, bridge abutments, retaining walls, bedding and backfilling of pipelines. This dissertation presents the findings of an extensive study carried out to determine the corrosivity of CLSM on ductile iron and galvanized steel pipelines. The study was performed in two phases and evaluated more than 40 different CLSM mixture proportions for their corrosivity. An extensive literature survey was performed on corrosion of metals in soils and corrosion of reinforcement in concrete environments to determine possible influential factors. These factors were used as explanatory variables with multiple levels to identify the statistically significant factors. Empirical models were developed for percent mass loss of metals embedded in CLSM and exposed to different environments. The first and only service life models for ductile iron and galvanized steel pipes embedded in CLSM mixtures were developed. Models indicated that properly designed CLSM mixtures can provide an equal or longer service life for completely embedded ductile iron pipes. However, the service life of galvanized pipes embedded in CLSM should not be expected to be more than the service life provided by corrosive soils.

La pâte feuilletée cuite se caractérise par une texture singulière aérée et friable, qui est générée par une alternance de fines couches laminées de matière grasse et de détrempe. L'objectif de la présente étude est d'observer les couches et de quantifier leur structure dans la pâte levée feuilletée. L'effet du nombre de couches sera étudié afin de faire varier leur structure. Deux techniques d'imagerie permettant d'accéder à des résolutions spatiales différentes (1.24µm et 0.5mm/pixel) ont été combinées : la MCBL pour caractériser les couches de matière grasse après laminage, et l'IRM pour étudier en dynamique l'évolution des couches pendant la fermentation. La méthode de traitement développée à partir des images MCBL a permis de quantifier l'épaisseur de chaque couche, et la rétractation des couches de détrempe après le laminage. Deux échelles de taille de ruptures dans les couches de matière grasse ont été identifiées grâce à la complémentarité des techniques d'imagerie. Une nouvelle méthode de quantification des proportions de trois composants (gaz, détrempe sans air et matière grasse) dans chaque pixel, appliquée aux images IRM pendant la fermentation a été utilisée. Elle a permis de suivre l'évolution de chaque couche de détrempe. Le nombre de couches (4,8 et 12), aussi bien que la position de chaque couche de détrempe, n'ont pas d'effet sur la vitesse d'expansion. L'étape de fermentation contribue le plus à l'expansion de la pâte levée feuilletée mais les couches de matière grasse n'ont pas de rôle à cette étape. Pendant la cuisson l'expansion relative de la pâte augmente de 20 à 65% de 4 à 32 couches de matière grasse et reste stable au-delà de 48 couc / Laminated dough is characterized after baking by a unique light and flaky texture which is the result of alternating thin sheeted layers of dough and fat. The aim of the present study was to visualize the layers and quantify their feature in Danish pastry like laminated dough. The effect of the number of layers was studied in order to have different structures of the layers. Two imaging techniques offering different spatial resolutions (1.24µm and 0.5mm/pixel) were combined: CLSM to characterize the fat layers after sheeting and MRI to study dynamically the layers during proving. The developed method from CLSM images allowed quantification of layers thickness and of the elastic recoil of dough layers. Two scales of fat breaches after sheeting were measured by complementary of the two imaging methods. A new method of quantification of the three components (gas, paste and fat) on each pixel in MRI images with partial volume during proving, was used. It made possible to monitor expansion of individual dough layers. Neither the number of fat layers (4, 8 and 12), nor the height position of dough layer, had an effect on the expansion rate. The proving step contributed to most of the expansion of Danish pastry, but with no specific role of fat layers. During baking, relative expansion of Danish pastry ranged from 20 to 65% for 4 to 32 fat layers and remained unchanged above 48 layers.

Clostridium difficile infection (CDI) is a major healthcare-associated disease with high recurrence rates. Host colonization is critical for the infectious process, both in first episodes and in recurrent disease, with biofilm formation playing a key role. The ability of C. difficile to form a biofilm on abiotic surfaces is established, but has not yet been confirmed in the intestinal tract. Here, four different isolates of C. difficile, which are in vitro biofilm producers, were studied for their ability to colonize germ-free mice. The level of colonization achieved was similar for all isolates in the different parts of the murine gastrointestinal tract, but pathogen burden was higher in the cecum and colon. Confocal laser scanning microscopy revealed that C. difficile bacteria were distributed heterogeneously over the intestinal tissue, without contact with epithelial cells. The R20291 strain, which belongs to the Ribotype 027 lineage, displayed a unique behavior compared to the other strains by forming numerous aggregates. By immunochemistry analyses, we showed that bacteria were localized inside and outside the mucus layer, irrespective of the strains tested. Most bacteria were entrapped in 3-D structures overlaying the mucus layer. For the R20291 strain, the cell-wall associated polysaccharide PS-II was detected in large amounts in the 3-D structure. As this component has been detected in the extrapolymeric matrix of in vitro C. difficile biofilms, our data suggest strongly that at least the R20291 strain is organized in the mono-associated mouse model in glycan-rich biofilm architecture, which sustainably maintains bacteria outside the mucus layer.

No description available.

No description available.

No description available.

Die Salicylsäure (SA) ist ein wichtiges Signalmolekül bei der Regulation der pflanzlichen Pathogenabwehr. as-1-ähnliche cis-Elemente in den Promotoren von vielen Abwehrgenen vermitteln SA- und auch Auxin-induzierbare Genexpression. Diese Elemente werden vom ASF-1/SARP-Proteinkomplex erkannt, dessen Hauptkomponenten DNA-Bindeproteine aus der TGA-Familie der pflanzlichen bZIP-Transkriptionsfaktoren sind. In dieser Arbeit wurden Fusionsproteine von TGA2.1, TGA2.2 und TGA1a mit GFP unter der Kontrolle des HBT-Promotors transient in Pflanzenprotoplasten oder stabil in transgenen Pflanzen exprimiert und direkt in lebenden Zellen über Fluoreszenz- und konfokale Laser-Scanning-Mikroskopie visualisiert. Bei den mikroskopischen Analysen konnte die Fluoreszenz der drei TGA-GFP-Fusionsproteine überwiegend im Kern (mit Ausnahme des Nukleolus) beobachtet werden. Allerdings ließen sich biochemisch mit Hilfe eines Antiserums gegen die beiden C Termini der TGA-Faktoren auch geringe Mengen von TGA2.1-GFP und TGA2.2-GFP in cytosolischen Extrakten der entsprechenden transgenen Pflanzen nachweisen. Fusionen der C terminalen Anteile von TGA2.2 und TGA1a an den C Terminus von CHS-GFP wurden bei transienter Expression ebenfalls im Cytosol beobachtet. Es konnte nicht abschließend geklärt werden, ob dass auf das Fehlen der NLS oder auf die Anwesenheit einer NES zurück zu führen ist. Die TGA-GFP-Fusionsproteine konnten das as 1-Element in vitro in Gelretardationsanalysen erkennen und in Form von Homo-oder Heterodimeren daran binden. Die TGA-GFP-Fusionsproteine waren auch in der Lage, die Expression des frühen (immediate-early) GST-Gens Nt103 in Blättern nach Induktion mit Salicylsäure oder Auxin zu beeinflussen. TGA2.1-GFP und TGA2.2-GFP zeigten im allgemeinen einen positiven Effekt auf die Nt103-mRNA-Menge (2-4-facher Anstieg verglichen mit dem Wildtyp), wobei sich der Effekt stärker auf die SA-induzierte Expression auswirkte als auf die 2,4-D-Proben. TGA1a-GFP schien die Expression von Nt103 in Blättern in beiden Fällen leicht negativ oder gar nicht zu beeinflussen. Die Mobilitätsparameter der verschiedenen TGA-GFP-Fusionsproteine im Kern wurden mit Hilfe von FCS, kombiniert mit CLMS, untersucht. Während die Mobilität des Kontrollproteins TetR-GFP, dass keine endogenen Interaktionpartner hat, einheitlich war, schienen Subfraktionen der TGA-GFP Fusionproteine in ihrer Mobilität beeinflusst. Generell konnte zwischen einer mobileren und einer weniger mobilen Fraktion unterschieden werden. Bei manchen Messungen waren die TGA-Faktoren im Kern sogar gänzlich immobil. Die relative Anteil von weniger mobilen, bzw. immobilen und mobilen TGA-faktoren unterschied sich in den unterschiedlichen analysierten Zelltypen (längliche und echte Epidermiszellen, Schießzellen, Trichomzellen). Um einen eindeutigen Effekt von Salizylsäure auf die Mobilität der TGA-Faktoren festzumachen, sind wegen der großen Variabilität weitere Messungen nötig.

Background: Syllids are a species rich annelid family possessing remarkable regenerative ability, which is not only the response after traumatic injury, but also a key step during the life cycle of several syllid taxa. In these animals the posterior part of the body becomes an epitoke and is later detached as a distinct unit named stolon. Such a sexual reproductive mode is named schizogamy or stolonization. The prostomium and the proventricle, a modified foregut structure, have been proposed to have a control function during this process, though the concrete mechanisms behind it have never been elucidated. Results: By using different experimental set-ups, histology and immunohistochemistry combined with subsequent cLSM analyzes, we investigate and document the regeneration and stolonization in specimens of Typosyllis antoni that were amputated at different levels throughout the antero-posterior body axis. The removal of the anterior end including the proventricle implies an incomplete anterior regeneration as well as severe deviations from the usual reproductive pattern, i.e. accelerated stolonization, masculinization and the occurrence of aberrant stolons. The detailed anatomy of aberrant stolons is described. A histological study of the proventricle revealed no signs of glandular or secretory structures. The ventricle and the caeca are composed of glandular tissue but they are not involved in the reproductive and regenerative processes. Conclusions: As in other investigated syllids, the proventricle region has a significant role during stolonization and reproduction processes in Typosyllis antoni. When the proventricle region is absent, anterior and posterior regeneration are considerably deviated from the general patterns. However, proventricle ultrastructure does not show any glandular component, thereby questioning a direct involvement of this organ itself in the control of reproduction and regeneration. Our findings offer a comprehensive starting point for further studies of regeneration and reproductive control in syllids as well as annelids in general.