691 research outputs found

    Some factors involved in growth and sporulation of Pilobolus Crystallinus Tode and Pilobolus Umbonatus Buller

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    Pilobolus umbonatus Buller and P. crystallinus Tode grew normally in a nitrogen atmosphere but their sporagnia were non-pigmented. When palced in anaerobic jars along with obligately anaerobic and obligately aerobic bacteria, the fungi grew in the range of oxygen concentrations too low for growth of the aerobic bacterium, but high enough to prevent growth of the anaerobe. The fungi did not grow when the oxygen was depleted to the point that allowed growth of the anaerobic bacterium. Catalase was not produced by the hyphae and trophocysts which normally grow beneath the surface of the medium, but was present in the aerial portions of these fungi. It is concluded that vegetative growth of P. umbonatus and P. crystallinus can occur under microaerophilic conditions but not under truly anaerobic conditions. Pilobolus umbonatus and P. crystallinus grew and sporulated on nutrient broth, nutrient agar, tryptic soy broth, tryptic soy agar, and glucose-asparagine agar when hemoglobin or nicotinic acid were added to these media. The growth-enhancing effect of hemoglobin was most pronounced at a low pH. Page\u27s observations that species of Pilobolus have an alkaline optimum pH and require thiamine for sporulation were confirmed. A spinach extract agar medium without further supplementation also provided for growth of these fungi. The hemoglobin media are transparent, easy to prepare, and convenient for routine culture maintenance, morphological studies, and classroom work with Pilobolus, and semi-synthetic hemoglobin media similar to the glucose-asparagine medium may be useful in some physiological studies

    An initial examination of sustainable leadership and employee engagement within extension nutrition programs /

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    Nutrition programs operated by Cooperative Extension organizations seek to provide nutrition education to a low-income audience nationally. There is research on the effectiveness of these programs, but gaps exist on the role of the leader and how their practices impact the educators and the programs as a whole. A transformative mixed-methods approach was used to capture both quantitative and qualitative data through a theoretical lens. Sustainable leadership and employee engagement were used as conceptual frameworks. Open-ended interviews with twelve leaders of Extension nutrition programs were conducted. An online survey was distributed to 100 nutrition educators to determine their perceptions of their leaders' sustainable leadership practices and also a personal employee engagement inventory, with a 63 percent return rate. The analysis of these interviews and surveys found that both the leaders and the educators reported the use of sustainable leadership practices by program leaders. The qualitative portion of the study revealed six of the seven leadership traits were described by the leaders during their interviews. Also, there was no significant relationship between the reported levels of sustainable leadership practices by the leaders and the educators. From the employee engagement inventory, the educators of averaged an average level of employee engagement. Lastly, there was a significant positive relationship between the use of sustainable leadership and educator employee engagement. The use of sustainable leadership and the relationship between employee engagement can have implications for these programs nationally. This and future research on leadership and its impact on employee engagement can help inform policy and practice within national nutrition programs.Dr. Barbara N. Martin, Dissertation Supervisor.|Includes vita.Includes bibliographical references

    Characterization of Adaptation in Phototropism of Arabidopsis thaliana

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    Kinetics for Phototropic Curvature by Etiolated Seedlings of Arabidopsis thaliana

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    Growth Distribution during Phototropism of Arabidopsis thaliana Seedlings

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