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This research describes the changes in cell morphology of Azotobacter vinelandii cells cultured in dialyzed soil medium. This particular culture medium was assumed to provide the bacteria with an environment similar to their natural habitat, the soil.

Trema micrantha L. Blume (Cannabaceae) is a pioneer tree species that is broadly distributed across the Neotropics. Taxonomic circumscriptions of this group have long been debated and problematic due to its morphological variation and broad geographic range. Delimitation of lineages within T. micrantha has remained unclear as molecular phylogenies with limited character and taxon sampling have not resolved the polyphyly of this group. To evaluate relationships within T. micrantha, I utilized phylogenetic, morphometric, and biogeographic methods. Using various DNA datasets, including ETS only, 5 DNA loci, plastome and whole nuclear ribosomal datasets, the recognition of 9 clades within T. micrantha as species was supported. Leaf shape morphometrics determined that several of these clades are morphologically diagnosable, but with some overlap in leaf shape, while ecological niche models elucidated ecological tolerance differences between clades. I thus evaluated these data across three species concepts for future taxonomic revisions.

Several subspecies of Monardella villosa (California Coyote Mint) have been distinguished on the basis of leaf thickness, shape, and trichome characteristics, yet many intermediates are known. We investigated morphological differences in natural populations of two subspecies (M. v. subsp. villosa and M. v. subsp. franciscana) in the Scott Creek watershed, north of Davenport, in Santa Cruz County, CA. Monardella villosa subsp. franciscana grows in coastal scrub in gulches and ocean terraces whereas subsp. villosa grows at more protected inland sites. Morphological difference between subspecies may be adaptations to these different habitats. I grew plants in a common garden at Cal Poly, San Luis Obispo to determine if the morphological differences were genetically based. I also conducted a reciprocal transplant of the two subspecies between inland and coastal populations to determine if they are locally adapted. The morphological differences (leaf hair density and length as well as leaf base angle) between subspecies were maintained in the common garden, yet no patterns of local adaptation were observed in germination or survival of the subspecies in reciprocal transplants in the first year. However, Monardella is a perennial plant and fitness differences may exist in later life stages that I have not yet measured.

Perfluorosulfonate ionomer (PFSI) membranes were annealed at elevated temperature for various periods of time in order to investigate the morphological effects of thermal treatments. For Nafion® 117, the DSC thermograms of Na+-, Cs+- and tetramethylammonium(TMA+)-form membranes show an endothermic peak develops upon annealing at 200ºC, indicating the development of crystallinity in the membrane. For these three samples annealed under same conditions, the heat of fusion (ΠH) values of the endothermic event increases with increasing counterion size. Larger tetraalkylammonium ions, tetraethylammonium(TEA+) and tetrapropylammonium(TPA+), result in no significant peak upon annealing at 200ºC. DSC thermograms of annealed Na+-form 3M Ionomer show no peak upon annealing and DSC thermograms of annealed TMA+-form 3M Ionomer show a very small peak that develops with annealing time at high equivalent weights. Annealed TMA+-form Dow Ionomer, which has a side chain shorter than both Nafion® and 3M Ionomer and a smaller mole% of side chains at the same equivalent weight, shows a relatively high ΠH value, which might also be related to its blocky nature. These results show that the isothermal crystallization kinetics of PFSI is affected by the counterion attached to the sulfonate group, the length of side chain, the mole% of side chains and the nature of the membrane. Water uptake analysis has been performed on annealed membranes, and the result shows that water uptake decreases with increasing degree of crystallinity. / Master of Science

In the present study, the sediment reworking rates, irrigation rates, and activity patterns of Axiotheata rubrocincta have been investigated. The results are compared with studies of other deposit feeding polychaetes. Because sediment ingestion is a feeding process, it has been necessary to examine some aspects of the feeding morphology and ecology of A. rubrocincta. Some of these findings differed from the results of Spies (MS.). The feeding biology and morphology of two additional maldanidae, Clymenella sp. and Praxillella affinis pacifica (Berkeley, 1929) have been studied. These finding are compared with earlier studies on maldanid genera and species by Pilgrim (1965b, 1966a).

<p> During the summer of 1970 a study was initiated to define factors controlling the biosphere in the lentic environment of the Precambrian Shield. Data were collected from nine lakes of varying size and depth located in a number of geological formations. Chemical, physical and biological conditions in these lakes were investigated at two sampling periods and the lakes were classified on the basis of morphology (surface area to volume area) and lithology (surficial and bedrock geology). Attempts were made to determine the influence of morphology and lithology on the chemical and biological conditions observed. Emphasis was placed on the relationships of these factors to aspects of the primary and secondary trophic levels in the lentic ecosystem including primary productivity and the standing crop and diversity of phytoplankton and zooplankton.</p> <p> The atmosphere, a third potential factor influencing lakes was investigated by means of a network of air monitoring stations (collecting both precipitation and 'dry fallout') located throughout the greater Sudbury area.</p> <p> The results of the study indicated that: 1. the lentic ecosystem in the Precambrian Shield area studied can be defined by simple chemical and physical variables. 2. the morphology of the lake basins (surface area to volume ratio) modified by lithology (primarily the presence or absence of limestone) is the major factor influencing biological activity. Lakes with a low surface area to volume ratio showed low productivity while lakes with a high surface area to volume ratio showed nigh productivity. Silica and calcium concentrations (influenced by the lithosphere) were important since relatively small changes in the concentration of these chemical species stimulated a response in the biosphere. 3. some of the lakes were affected by concentrations of sulphates conveyed to the water by the atmosphere. Observed effects included increases in the hydrogen ion concentration in lakes with low calcium concentrations (poorly buffered) and a depression of the diversity of both primary and secondary trophic levels.</p> / Thesis / Master of Science (MSc)

<p> Etch pits can be produced in iron whose shape reflects the crystallography of the crystal. It is shown that pit morphology can be adequately predicted from an orientation dependent dissolution theory. The influence of an air-formed surface oxide film on pit nucleation and morphology is demonstrated. </p> / Thesis / Master of Science (MSc)

This thesis examines the semantic processing of morphologically complex words during visual word recognition. In a series of three experiments this thesis addresses (i) the role semantic transparency during compound word reading, (ii) the nature of the conceptual structure of compound words and its effect on visual word recognition, and (iii) the time-course of semantic access during the visual comprehension of derived words. Chapter 2 documents evidence that the outcome of the compound semantic transparency effect is dependent upon the amount of language experience of the reader. We report that high compound transparency inhibits less experienced readers during naturalistic reading, yet facilitates processing among relatively more experienced readers. This study is the first to demonstrate that semantic processing of compound words is driven by individual reading skill. The study reported in Chapter 3 tests the hypothesis that the conceptual representation of a compound is based on a relational structure linking the compound’s constituents. Across two lexical decision datasets, Chapter 3 reports that greater entropy (i.e., increased competition) among a set of conceptual relations associated with a compound gives rise to longer lexical decision latencies. This finding indicates that the same compound word form is associated with many potential relational meanings, and that these meanings compete for selection during visual word recognition. Chapter 4 concerns the time-course of lexical-semantic access during derived word recognition. Existing accounts of derived word recognition widely disagree about whether access to conceptual information is granted prior to morphological decomposition. We report evidence which shows that the semantics of derived words and their stems are accessed in concert with morphological sources of information. These results challenge theoretical accounts that advocate strictly serial access to (morpho-orthographic then morpho-semantic) lexical cues. Overall, the empirical evidence presented in this thesis suggests that morphological processing involves rapid and concurrent access to many sources of conceptual information. These findings align with a view of complex word processing in which the cognitive system utilizes as many cues as possible in order to maximize the opportunity of obtaining the meaning of the word. / Thesis / Doctor of Philosophy (PhD)