Klebsiella pneumoniae is a Gram negative, enteric bacterium that frequently causes disease in immunocompromised individuals. These types of infections are often associated with the presence of indwelling medical devices, which provide a site for the organism to attach and subsequently form a biofilm. A key component in K. pneumoniae biofilm formation in vitro is type 3 fimbriae. The two main components of this project have been to determine if type 3 fimbriae are an in vivo virulence factor using a mouse model of catheter associated urinary tract infection (CAUTI) and to examine the mechanism by which the production of type 3 fimbriae are regulated. Using a mouse model in which a silicone tube is implanted into the bladder of mice, mimicking the effects of catheterization, we have been able to show that type 3 fimbriae are required for colonization and persistence. Using different time points and conditions, we demonstrated that there are conditions when type 3 fimbriae alone are sufficient for colonization and other conditions where both type 1 and type 3 fimbriae have unique roles in colonization and persistence. Additionally, competition experiments showed that neither fimbrial mutant alone, or a double mutant in type 1 and type 3 fimbriae could compete with wildtype K. pneumoniae. In most animals, only wild-type bacteria were recovered by 24 hours post-inoculation. This work reinforced the role of type 1 fimbriae in pathogenesis and showed, for the first time, a role for type 3 fimbriae using an in vivo model. Our early work has indicated that type 3 fimbriae are regulated at least in part by the intracellular levels of the secondary messenger molecule cyclic di-GMP. Downstream from the type 3 fimbrial operon a gene encoding a phosphodiesterase is present; the product of this gene breaks down cyclic di-GMP. In the absence of this gene the levels of type 3 fimbrial expression are increased. Also adjacent to the mrk operon is a two-gene operon containing the determinants we have named mrkH and mrkI. mrkH encodes a PilZ domain containing protein, which we have shown binds cyclic di-GMP. Using a transcriptional fusion we have shown that the mrk gene promoter is activated modestly in the presence of MrkH, but when MrkH and MrkI are both present the activity is increased 100-fold. This has lead to the hypothesis that MrkH and MrkI interact, which we have been able to demonstrate using copurification procedures. This interaction appears to occur in a cyclic di-GMP dependent manner with the resulting protein complex binding to the mrk promoter region and activating the expression of type 3 fimbriae.

The cutwidth of different graphs is a topic that has been extensively studied. The basis of this paper is the cutwidth of complete n-partite graphs. While looking at the cutwidth of complete n-partite graphs, we strictly consider the linear embedding and cyclic embedding. The relationship between the linear cutwidth and the cyclic cutwidth is discussed and used throughout multiple proofs of different cases for the cyclic cutwidth. All the known cases for the linear and cyclic cutwidth of complete bipartite, complete tripartite, and complete n-partite graphs are highlighted. The main focus of this paper is to expand on the cyclic cutwidth of complete tripartite graphs. Using the relationship of the linear cutwidth and cyclic cutwidth of any graph, we find a lower bound and an upper bound for the cyclic cutwidth of complete tripartite graph K_(r,r,pr) where r is odd and p is a natural number. Throughout this proof there are two cases that develop, p even and p odd. Within each case we have to consider the cuts of multiple regions to find the maximum cut of the cyclic embedding. Once all regions within each case are considered, we discover that the upper and lower bounds are equivalent. This discovery of the cyclic cutwidth of complete tripartite graph K_(r,r,pr) where r is odd and p is a natural number results in getting one step closer to finding the cyclic cutwidth of any complete tripartite graph K_(r,s,t).

This thesis investigates the flexural behavior of interlocking compressed earth block (ICEB) shear walls. In-plane cyclic tests were conducted to evaluate the performance of three flexure dominant large scale ICEB specimens: a slim wall with a 2:1 height to width aspect ratio, a flanged wall, and a wall with an opening at the center. Following the experimental investigation, two types of analyses were conducted for calculating the ultimate strength of flexure dominant ICEB walls: a nonlinear static analysis model assuming lumped plasticity and a plastic analysis model. In addition, incremental dynamic analysis was conducted to address the seismic performance of flexure dominant ICEB buildings. Based on the database from the incremental dynamic analysis, the collapse potential of demonstration ICEB buildings were compared for the countries of interest.

[Truncated abstract] Characterising the behaviour of calcareous sediments that possess some degree of bonding between their constituents has attracted worldwide research interest in recent years. Although many recent studies have made significant contributions in delineating the behaviour of these sediments, there is still paucity of information particularly on the cyclic behaviour of cemented calcareous soils. This thesis describes in detail the characteristic features of cemented calcareous soils and proposes methods for characterising their cyclic behaviour. Two different calcareous soils Goodwyn (GW) and Ledge Point (LP) soils representing extreme depositional environments were examined in this study. Artificially cemented sample were created using the CIPS (Calcite Insitu Precipitation Systems) technique, considering its superiority over other most commonly available cementation techniques in replicating the natural pattern of cementation, and the behaviour of natural calcarenite under monotonic loading conditions. The experimental program involved triaxial testing of both uncemented and calcite-cemented calcareous soils under different loading conditions, i.e. isotropic compression tests to high-pressure (16 MPa), monotonic shearing tests, undrained cyclic shearing tests and undrained monotonic post-cyclic shearing tests. Significant emphasis has been placed on the cyclic behaviour of these soils. Internal submersible LDVTs were used for the accurate and continuous measurement of strain down to about 10-5

Abstract not available

Z-pinning is a through-thickness reinforcement technology for polymer composite materials that has been developed and commercialised over the past fifteen years. The through-thickness reinforcement of composites with thin metallic or fibrous pins aids in suppressing delamination, improving impact damage tolerance and increasing joint strength. Z-pins are applied to the composite part during its manufacture. Pins are embedded within sheets of foam and placed over the unconsolidated part. Subsequently, the foam is compacted and the pins transferred into the part, which is usually an uncured prepreg. In this manner, large numbers of pins can be inserted quickly and easily. The pinned composite is then cured using conventional processes. The use of z-pins is currently limited to several high performance composite structures, most notably Formula One racing cars and F/A-18 E/F (Superhornet) fighter aircraft, although the technology has potential applications in a d iverse variety of aerospace and non-aerospace composite structures. A limited understanding of the mechanical performance of z-pinned parts under high load and fatigue loading conditions currently hinders the application of z-pinned composites. The aim of this PhD project is to investigate the mechanical properties, strengthening mechanics and failure mechanisms of z-pinned carbon/epoxy laminates and joints. The effect of z-pin reinforcement on the tensile and flexural properties of laminates under monotonic and fatigue loading is studied. The sensitivity of these properties to the volume content and diameter of the z-pins is systematically studied by experimentation and analytical modelling. This PhD also evaluates the efficacy of z-pins in improving the load-bearing properties of carbon/epoxy lap joints. Improvements to the room temperature and elevated temperature properties of z-pinned lap joints under monotonic and fatigue tensile loading were determined. The effect of strain rate on the load-bearing properties of z-pinned lap joints was also evaluated. A further aim of the PhD project was to assess the z-pin manufacturing process and the microstructural damage caused by that process. The outcome of this study augments the analysis of the me chanical properties of z-pinned laminates and joints.

Thesis (Ph.D.)--University of Toledo, 2006. / "In partial fulfillment of the requirements for the degree of Doctor of Philosophy in Biomedical Sciences." Major advisor: Brian G. Rowan. Includes abstract. Document formatted into pages: iv, 204 p. Title from title page of PDF document. Title at ETD Web site: Molecular mechanisms of protein kinase a signaling pathway on estrogen receptor action in breast cancer . Bibliography: pages 59-65, 100-104, 137-150, 167-202.

<p>This thesis investigates three different surface modifications, and the route to design and synthesize them. The thesis is therefore divided into three sub- projects. (i.) Design and synthesis of a peptide which secondary structure could be controlled by a negatively charged surface. (ii.) Design and synthesis of a cyclic peptide, that would self-organize prior to surface interaction, using the type I anti-freeze protein of a winter flounder as template. (iii.) The use of solid-phase synthesis to make the synthesis of SAM-molecules easier.</p>

Ductile steel plate shear walls are an established lateral load resisting system. Past research indicates that cold-rolled infill panels less than 1 mm in thickness present one solution to an overstrength problem arising from selecting an infill panel thickness based on ease of welding and handling. This research program examines several possible welding procedures and joint geometry to connect the thin infill panel to the thick boundary elements. Primary welding parameters include short-circuiting gas metal arc welding process, electrode and shielding gas selection, heat input, and use of a chill strip. Four configurations of the infill panel-to-boundary element joint and two configurations of a lap splice joint between two sheets of thin steel in the infill panel were tested in monotonic tension and cyclic tension-compression. A quasi-static cyclic test of a single-storey moment resisting frame steel plate shear wall validated the use of one welding procedure and joint geometry. / Structural Engineering

The objective of this research program is to further evaluate the performance and constructability of reinforced concrete (RC) column-steel beam-slab systems (RCS) for use in low- to mid-rise space frame buildings located in regions of high wind loads and/or moderate seismicity. To better understand these systems, two full scale RCS cruciform specimens were tested under bidirectional quasi-static reversed cyclic loading. The experimental portion of this research program included the construction and testing of two full-scale cruciform specimens with identical overall dimensions but with different joint detailing. The two joint details evaluated were joint cover plates and face bearing plates with localized transverse ties. The construction process was recorded in detail and related to actual field construction practices. The specimens were tested experimentally in quasi-static reversed cyclic loading in both orthogonal loading directions while a constant axial force was applied to the column, to simulate the wind loads in a subassembly of a prototype building. To compliment the experimental work, nonlinear analyses were performed to evaluate the specimen strength and hysteretic degradation parameters for RCS systems. In addition, current recommendations in the literature on the design of RCS joints were used to estimate specimen joint strength and were compared with the experimental findings.