Thesis (M.A.) -- Central Connecticut State University, 2005. / Thesis advisor: Jack Tessier. "... in partial fulfillment of the requirements for the degree of Masters of Arts, Biology, Ecology and Environmental Science." Includes bibliographical references (leaves 23-25). Also available via the World Wide Web.

Thesis (Ph. D.)--University of Washington, 1996. / Vita. Includes bibliographical references (leaves [142-157]).

A crude extract of axenically grown amoebae was used as antigen in order to develop an AB microELISA for the detection and quantitation of E. histolytica-specific IgG antibodies. This ELISA was used to screen individual sera of patients suffering from invasive amoebiasis (n=47)and control individuals(n=33). Significant titers of E-histolytica- specific IgG antibodies were present only in sera of patients suffering from invasive amoebiasis. The AB-microELISA had a sensitivity of 98% and a specificity of 97%. Immunoblot analysis of the crude E. histolytica extract indicated the presence of several antigenic proteins. One of the common antigenic proteins recognized by the individual patients' sera had a molecular weight of 160.170 kDa Sera of five patienta with high titers of E. histotytica-specific IgG antibodies were used to prepare a serum pool. This pooled serum was used for immunoscreening of an E. histolyitca cDNA expression library prepared in the phage vector l ZAP-II. A strongly immunoreactive phage done was identified, from which he recombinant phagemid was released by in vivo excision for characterization of the cDNA insert.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

84 pp. / First Edition Published, 2001 / The noxious weed problem in the western United States has been described as, a biological forest fire racing beyond control because no one wants to be fire boss. Indeed, when small weed infestations are left unchecked, they can grow exponentially and spread across the land much like a slow-moving biological wildfire. However, land consumed by fire usually recovers and is often more productive than before the fire occurred. On the other hand, land consumed by noxious weeds may be irreversibly changed and never again reach its full biological potential.

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Prescribed fire has become a known silvicultural disturbance on public and private lands in the United States. Implementation of fire as a treatment allows land managers to reach specific goals through lower operational costs compared to mechanical or chemical means. Differences in management strategies for forested ecosystems often lead to individual plant species being overlooked. With an increasing number of invasive plants spreading into North American ecosystems, response of invasive plants to fire could potentially affect management decisions. It is important to understand the fire-response of invasive plants as stimulatory, neutral or suppressive to aid in future management of ecosystems. This study quantified the impact of small-scale prescribed fire on the invasive plant Japanese chaff flower (Achyranthes japonica; hereafter Chaff), at three different sites in Southern Illinois. The hypothesis was that fire would decrease the density and survival of chaff. Fixed sample plots were created (24 plots per site). At each site a set of unburned plots (control 8-16 plots) and treatment plots (burned 8-16 plots) were established, resulting in 32 burned plots and 32 unburned plots between 2015 and 2016. To best understand the effects fire had on Chaff, plant phenology was classified into four different life stages (cotyledons, seedlings, juveniles, adults) during each survey of the study plots. Using multi-model inference, one candidate model set was created to evaluate the survival of adult chaff flower, and 4 model sets to investigate the change in density of adults, juveniles, seedlings, and cotyledons respectively. The models had sites, treatment (burned versus unburned), and year (2015 and 2016) as explanatory variables. We compared the models using Akaike’s Information Criterion corrected for sample bias (AICc) to compare and rank models. The top model described survival of adult chaff flower, retained only treatment (burn vs. unburned) as a variable, and showed that Chaff survival was lower in burned plots than in unburned plots (β = -0.30, SE = 0.02), with the effect being greater at site 3 where about 46% of adult plants died after being treated with fire. The top model describing the change in adult plant density retained an interaction between year and site, and showed that adult chaff density increased from 2015 to 2016 on sites 1 and 2 by 32% and 14%, respectively. However, on site 3 there was nearly a 50% decrease in adult chaff flower plants in 2016. The juvenile and cotyledon stages showed similar results, by retaining an interaction between site and treatment, with an addition to year; the data showed a higher number of juveniles and cotyledons in the unburned plots than the burned plots going from 2015 to 2016. Seedling density decreased from 2015 to 2016 on sites 2 and 3, but on site 1 there was a slight increase. This increase could be largely due to the ability of the plants independent ability to replenish gaps in the population. Chaff can grow from the cotyledon class to an adult plant in a single growing season with sufficient sunlight, nutrient, and space. This study showed that a single entry of low intensity prescribed fire can kill established adult chaff plants. A single entry of prescribed fire had a direct negative impact on emerging young chaff plants, but the traits and characteristics of this invasive species which enable it to persist after a disturbance, as well as the documented variability on control associated with seasonal and local site differences, suggest that fire treatment alone may not be enough to halt its spread. Future work could focus on more burns, with repeated entry of fire in chaff flower populations and burns conducted at higher intensities and at different times of the year to further explore the impacts of fire on this invasive species.

Background: Invasive pulmonary aspergillosis (IPA) is a common cause of mortality in haemato-oncology patients and early diagnosis is vital for improving outcomes. Since lung biopsy in this acute setting is rarely performed due to the associated risks, an empirical strategy remains the standard of care in many haematology units, but leads to overtreatment with antifungal drugs, which have significant side-effects. This project has developed novel approaches for detecting IPA, allowing early and specific treatment of genuine fungal infection. Methods: A combination marker approach involving a new Aspergillus qPCR assay, an EORTC/MSG-endorsed GM ELISA and an Aspergillus LFD, was used to establish a robust diagnosis of IPA from clinical broncho-alveolar lavage (BAL) fluid samples. The inflammatory cytokine profile associated with IPA biomarker positive BAL fluid was also evaluated. Finally, antigen and qPCR detection were combined in a proximity ligation assay (PLA), to demonstrate proof-of-principle for a diagnostic assay for the earliest possible detection of fungal infections. Results: A dual testing approach involving a novel MIQE-compliant Aspergillus qPCR assay and an Aspergillus LFD showed a sensitivity and specificity of 100% and 94%, respectively in BAL fluid, unlike in blood where this approach was not sensitive. Results confirmed previously published concerns over the repeatability of GM in serum, whereas BAL GM results appear stable. Biomarker detection results in exhaled breath condensate did not correlate well with results in BAL fluid samples. Respiratory samples did not identify a distinct inflammatory marker profile in IPA. Finally, antibodies raised against JF5 mannoprotein were used to develop a PLA test to detect active growth of Aspergillus. Conclusions: The optimised qPCR is a very sensitive and highly specific aid in IPA diagnosis. A combination biomarker approach could be incorporated into a diagnostic-driven approach to patient management to direct antifungal treatment to patients with evidence of invasive fungal disease.

Bioturbation by invasive crayfish can significantly alter sediment properties and its transport in invaded water bodies; however, the indirect impacts of this on ecosystem functioning are poorly understood. In this thesis I present data from mesocosm and field manipulation experiments used to assess the effect of bioturbation by three widely distributed invasive crayfish species (Procambarus clarkii, Pacifastacus leniusculus and Astacus leptodactylus) on a variety of ecosystem properties across seasons. In the mesocosm experiments, P. clarkii caused significantly more bioturbation than the other species, although increased bioturbation by all species in the spring and/or summer was associated with: reduced dissolved oxygen concentrations in near-surface water, indicating a large increase in oxygen demand by the water column; increased methane oxidation potential within the water (MOPwat), indicating the re-suspension of methane oxidising bacteria (MOB) along with the sediment; and a shift in zooplankton community structure towards dominance by large cladoceran species. Stable isotope analysis of the zooplankton showed a strong relationship between δ13C and MOPwat, suggesting that bioturbation increases MOB consumption. Given the importance of zooplankton as a trophic link to the higher food web, crayfish bioturbation may increase the importance of methane derived (chemosynthetic) carbon in invaded ecosystems. Temperature was identified as the key driver of seasonal variations in crayfish bioturbation intensity through laboratory mesocosm experiments, enabling estimation of the full annual pattern of bioturbation intensity for each species. The optimal temperature for P. clarkii was much higher than for the other species meaning that its bioturbation impacts exhibited large seasonal fluctuations whilst P. leniusculus and A. leptodactylus maintained a lower but more consistent level. Field manipulation experiments of enclosed sections of Chalgrove Brook, Oxfordshire, found significant bioturbation activity by P. leniusculus in early autumn; however, the increase in turbidity was too small to detect other effects observed in the mesocosm experiments.