Thesis (Ph.D.)--The University of Memphis, 2007. / (UMI)AAI3293754. Source: Dissertation Abstracts International, Volume: 68-12, Section: B, page: 7739. Adviser: Stephan J. Schoech.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6236. Adviser: Evan H. DeLucia. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6167. Adviser: Jeffrey D. Brawn. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3552. Adviser: Patrick J. Weatherhead. Includes bibliographical references (leaves 137-162) Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3676. Adviser: Uriel D. Kitron. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

<p> Natural selection, the driving force behind evolution, acts on individual phenotypes. Phenotypes are the result of an individual&rsquo;s genotype, but the development from genotype to phenotype is not always accurate and precise. Developmental instability (DI: random perturbations in the microenvironment during development) can result in a phenotype that misses its genetic target. In the current study I assert that developmental instability may itself be an evolvable trait. Here I present evidence for DI&rsquo;s heritability, selectability, and phenotypic variation in the form of empirical data and evidence from the literature from the years 2006 through 2016. Phenotypic variation contributed by DI was estimated using fluctuating asymmetry and was found to contribute up to 60% of the phenotypic variation in certain trait types. I suggest that selection against developmental instability in some traits may result in higher evolvabilities (i.e., rates of evolution) for those traits or for entire taxonomic groups.</p><p>

<p> Land managers and researchers are currently concerned with expanding populations of invasive species across North America. Invasive species are non-native species, introduced intentionally or unintentionally to an environment, which have the potential to cause economic or ecological damage through modifications of biodiversity and structure of the resident community that it invades. While a great deal of attention has been given to the negative effects of non-natives, research regarding the community-level effects in native Illinois natural areas is limited at best. We address the issue of invasive species at the plant community level by assessing the impact that Eurasian native <i> Alliaria petiolata</i> (M. Bieb) Cavara and Grande (Brassicaceae) has on pine plantation understory communities at Sand Ridge State Forest (Mason County, IL). <i>Alliaria petiolata</i> is a biennial species possessing a multitude of characteristics that promote its success as an invasive plant across much of the United States. To properly evaluate the community-level response of Sand Ridge State Forest to invasion by garlic mustard, we experimentally invaded 72 plots with <i>A. petiolata</i> seeds or rosette transplants and subjected plots to different mineral nutrient amendments and management techniques. <i>Alliaria petiolata</i> population density was monitored over a 5-year period to evaluate the susceptibility of Sand Ridge State Forest to invasion, and a vegetative census was conducted to assess the effects of <i>A. petiolata</i> invasions on native understory plant communities using species richness (S), equitability (J), and the Shannon diversity index (H&rsquo;) as indicators. We present evidence that <i>A. petiolata</i> densities significantly increased over time, and that altering nutrient availability or management practices do not differentially affect the success of invasive <i>A. petiolata</i> at Sand Ridge State Forest. Additionally, we found that <i>A. petiolata </i> invasions do result in reduced diversity in this system, however nitrogen availability and management practices can modulate diversity losses. </p><p>

The presence on wheat crops of the fungal pathogen Fusarium graminearum poses serious financial and health-related problems in Canada. The fungus causes a significant decrease in yield and quality of the crop, in addition to producing mycotoxins, which can survive the milling process. Signaling processes involving protein kinases are thought to play a major role in the activation of a host defense response. A research project employing western detection experiments and kinase assays was initiated to determine whether the presence of F. graminearum caused changes in the level of protein kinases in cultivars Frontana (resistant) and Roblin (susceptible). The results indicated that F. graminearum had modest effects on phosphorylation levels of threonine and tyrosine residues. Moreover, differences occurred between the resistant and susceptible cultivar. Kinase assays did not show any variation in activity in either cultivar. A MAPK (w&barbelow;heat M&barbelow;APK h&barbelow;omologue-1&barbelow;) homologue was cloned, sequenced and shown to be identical to the wck-1 sequence found in the public database. Preliminary results show an increase in the level of transcript in the Fusarium-treated Frontana sample. The implications of the results are discussed.

Metaphyton is a poorly studied algal community that can develop into large floating mats in rivers, wetlands and lakes. In this thesis, I examined the role of nutrients in determining differences in metaphyton biomass both seasonally and spatially within a lowland temperate river, the Rideau River, Ontario. The source of nutrients was also examined by analyzing the stable isotope signature of the mats in relation to adjacent land-use. Metaphyton in the river was restricted to slow-flowing areas of the littoral zone and was mainly comprised of filamentous green algae (Spirogyra and Cladophora). From the results of this study, conditions for the presence of large metaphyton communities in rivers include: (1) shallow littoral zones with minimal current, (2) the presence of macrophytes (as a substratum), and (3) moderate to high nutrient concentrations (particularly dissolved inorganic nitrogen). To control metaphyton in the Rideau River, the nitrogen loading to the system must be considered as well as phosphorus. (Abstract shortened by UMI.)

Indirect calorimetry and nitrogen excretion measurements allow quantifying dynamic changes in the rates of carbohydrate, lipid and protein oxidation over time. Although measuring oxygen consumption and carbon dioxide production is relatively simple, only a few studies presented these two measurements in avian models, but none used the data to calculate rates of metabolic fuel oxidation. Therefore, the first goal of this study was to use indirect calorimetry and nitrogen excretion measurements to quantify the rates of lipid, carbohydrate and protein oxidation over time in ruff sandpiper during cold exposure and terrestrial locomotion. Even though the data obtained does not allow me to test these hypotheses, one finding is really interesting. The ruff sandpiper may use intramuscular lipid reserves to power muscle contractions, but these small reserves would probably be depleted within a short period of time, especially during flight. Therefore, this species may have the capacity to use a secondary mechanism to carry lipids from the adipocytes to the working muscles. Because plasma albumin is present in limited amounts, and because each albumin molecule can only bind a limited number of fatty acids, VLDL-TAG from the liver may be a good way to insure that the working muscles do not run out of fuel. (Abstract shortened by UMI.)