Thesis (Ph. D.)--University of Wyoming, 2006. / Title from PDF title page (viewed on Dec. 20, 2007). Includes bibliographical references (p. 78-83).

A mathematical model of Limiting Dilution Analysis for two limiting parameters is presented and investigated. Limiting Dilution Analysis is a microbiological cell assay developed for immunological application. In the given case we deal with the interaction between B lymphocytes, macrophage derived factor and T-independent antigens. The state of the art is that quantitative statements are only possible if one cell type (in general the B cells) is limiting and all others are in excess present. The basis for this thesis is a set of experiments in which B cells and macrophage derived factor are limiting and all other involved cells and factors are in saturating amounts present. It is shown that so far presented suggestions on modeling Limiting Dilution Analysis for two limiting cell-types are not suitable for this problem. Further, a mathematical model based on data is presented and interpreted in immunological terms with the help of a set of partial differential equations. The basis for the interpretation of the model are changes in affinity and saturation effects, both not incorporated in the so far presented models of the assay. In particular the relevance of mathematical interpretation of this process for the identification of new concepts as the saturation effects is stressed. The model of partial differential equations is highly non-linear but offers the possibility of interpreting the highly interrelated processes apart from each other. / Graduation date: 1994

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Microbiology and Molecular Genetics." Includes bibliographical references (p. 140-151).

Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on August 5, 2009). Includes bibliographical references (p. 123-138).

Title from title page of PDF (University of Missouri--St. Louis, viewed Feb. 10, 2010). Includes bibliographical references.

Thesis (Ph. D.)--University of Missouri--Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 156-175).

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

In a series of field and watershed scale studies, the genetic diversity of Escherichia coli in secondary habitats (e.g. soils and sediments) of an agricultural watershed was assessed in order to examine the dynamics of E. coli inhabiting these matrices and to determine their contribution to waterborne populations. Using replicated field plots, persistent subpopulations of E. coli were observed to be significantly affected by hillslope position due to inherent differences in soil texture and moisture content. The dynamics of E. coli populating tile drainage effluent in a working cultivated field were monitored and it was observed that putatively naturalized E. coli dominated the effluent after approximately 55 days following manure amendments. The contribution of tile drainage effluents to the waterborne E. coli population in an adjacent stream was exponentially related to tile discharge rates, regardless of whether the effluent was populated by manure-associated or naturalized E. coli strains. Streambed E. coli populations differed according to stream geomorphological features, with strains responding to sediment texture and water velocity distributions among the features. In a temporal study of sediment E. coli, population turnover was observed to be affected by sediment redistribution in highenergy stream reaches and was stabilized by immigration from adjacent catchment sources in low-energy stream reaches. Reach-specific connectivity between sediment and waterborne E. coli populations was observed in this watershed. Reach- and catchmentscale hyporheic processes are speculated to be occurring, which may be in part influenced by strain-dependent attachment behaviour of E. coli strains in disjoint stream reaches influenced by different catchment sources of E. coli. The attachment of waterborne E. coli to suspended particles was observed to be associated with land use, water quality and suspended particle variables. The relationship of land use type to particle attachment reinforces the hypothesis that strain-specificity in attachment behaviour can affect the transport of E. coli in fluvial systems. This work provides evidence that putatively naturalized strains in cultivated fields can contribute a large part to waterborne E. coli, and that reach-specific hydrological factors need to be considered when relating sediment- to waterborne E. coli in fluvial systems.

Thesis (M.S. - Hydrology and Water Resources)--University of Arizona, 1989. / Includes bibliographical references (leaves 147-156).

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.