Spiders weave intricate webs for catching prey, providing shelter and setting mating rituals; arguably the most notable of these creations is the orb web. In this thesis we model the essential vibrations of orb webs by first considering a spider web as a multilinked structure of elastic strings. We then solve the associated eigenvalue problem using a Chebyshev pseudospectral collocation method to discretize the system. This thesis first examines the vibrations of webs with uniform material properties throughout, then investigates the effects of using biologically realistic material parameters for silks within a single web. Understanding how spiders detect and react to the vibrations produced by their webs is of interest for both biological and engineering applications. / Master of Science

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Natural enemies are members of complex ecological communities, and their ability to contribute to the biological control of pest organisms is strongly influenced by a convoluted network of ecological interactions with many other organisms within these communities. Researchers must develop an understanding of the mechanisms that shape trophic webs to predict and promote top-down effects of predators. The behavior of predators can have a strong influence on their potential as biological control agents. Web-building spiders are a useful example organism for the study of natural enemy behavior because of the experimentally tractable nature of their foraging behavior. Specifically, patterns in microhabitat utilization and web construction by spiders provide insights into foraging behavior and pest-suppression potential. In field collections, spiders were found to utilize microhabitats in a species-specific manner. Molecular gut-content analysis and a mathematical model showed that two spiders belonging to different web-building guilds differed in their dependence on microhabitat-specific prey activity-densities. In particular, the sheet-weaving guild constructed webs in microhabitats with the highest densities of springtails (Collembola). High dependence on this non-pest prey also correlated with evidence of increased intraspecific competition, and implies a potential negative effect of springtails on the consumption of pest insects, such as aphids. In laboratory two-choice assays, sheet-weaving spiders selected microhabitats and constructed webs in a flexible, stepwise manner, which allowed spiders to regulate their investment of silk resources to match the profitability of the microhabitat. Spiders also exhibited prey-specific shifts in foraging behavior, constructing webs in the presence of mobile, non-pest springtails, but utilizing active foraging tactics in the presence of sedentary, pest aphids. However, in factorial no-choice assays, pest-consumption rates were not significantly affected by the presence of non-pest springtails, indicating that prey-specific foraging-mode shifts are compatible with biological control. From these results, it is clear that the flexible foraging behavior of web-building spiders has a strong influence on their roles in ecological communities and their position within food webs. This dissertation highlights the importance of understanding the nuances of natural-enemy behavior for properly assessing and promoting biological control services.

In this thesis, the interaction pattern for a class of soliton solutions of the Kadomtsev- Petviashvili (KP) equation (−4ut + uxxx + 6uux )x + 3uyy = 0 is analyzed. The complete asymptotic properties of the soliton solutions for y → ±∞ are determined. The resonance characteristic of two sub-classes of the soliton solutions, in which N- incoming line solitons for y → −∞ interact to form N+ outgoing line solitons for y → ∞, is described. These two specific sub-classes of (N-,N+)-soliton solutions are the following: 1) [(2, 3), (2, 4), (2, 5)], 2) [(3, 2), (3, 3), (3, 4)]. The intermediate solitons and the interaction regions of the above soliton solutions are determined, and their various interaction patterns are explored. Maple and Mathematica are used to get the 3 dimensional plots and contour plots of the soliton solutions to show their interaction patterns. Finally, the spider-web-structures of the discussed solitons of the KP equation are displayed.

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The purpose of this research was to study the lived experience of being a strategic leader, described as the black box of leadership, and to extend the limited research in this field. The researcher utilised the qualitative ethnographic methodology of direct observation, observing 138 discrete critical incidents that made up the lived experience of the five strategic leaders in the sample. The researcher further utilised observation tools from the field of Neuro Linguistic Programming, personal experiences, metaphors, allegories, analogies as well as deep personal introspection to make sense of the lived experience of the five CEOs. The primary research objective was to answer the question: What do CEOs do and how do they do it? A further related objective was to explore how they think about what they do. The research answered these questions by prising open the 'black box' of the lived experience of the strategic leader. The result of the research is the pure leadership spider web model. The pure leadership spider web model breaks down the lived experience of the strategic leader, the content of the black box, into eight dimensions: the pillars that make up the personal leadership philosophy; emotional states of mind brought to bear in meetings; kinaesthetic patterns used during meetings; meeting dynamics; emotional states brought to bear on day-to-day shop-floor engagement; emotional states brought to bear on leadership engagement sessions with other like business leaders; frames of mind governing the day-to-day experiences; and The Magic Language Box. / Business Management and Entr / DBL

The purpose of this research was to study the lived experience of being a strategic leader, described as the black box of leadership, and to extend the limited research in this field. The researcher utilised the qualitative ethnographic methodology of direct observation, observing 138 discrete critical incidents that made up the lived experience of the five strategic leaders in the sample. The researcher further utilised observation tools from the field of Neuro Linguistic Programming, personal experiences, metaphors, allegories, analogies as well as deep personal introspection to make sense of the lived experience of the five CEOs. The primary research objective was to answer the question: What do CEOs do and how do they do it? A further related objective was to explore how they think about what they do. The research answered these questions by prising open the 'black box' of the lived experience of the strategic leader. The result of the research is the pure leadership spider web model. The pure leadership spider web model breaks down the lived experience of the strategic leader, the content of the black box, into eight dimensions: the pillars that make up the personal leadership philosophy; emotional states of mind brought to bear in meetings; kinaesthetic patterns used during meetings; meeting dynamics; emotional states brought to bear on day-to-day shop-floor engagement; emotional states brought to bear on leadership engagement sessions with other like business leaders; frames of mind governing the day-to-day experiences; and The Magic Language Box. / Business Management and Entr / DBL