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Tests of Adaptive Coloration Hypotheses for Madtom (Notorus) Catfishes (Siluriformes: Ictaluridae)Stokes, Amanda 19 December 2003 (has links)
Predators select for defensive adaptations, such as stings, toxins, and camouflage color patterns. Madtoms, Noturus, are diminutive catfishes with dorsal and pectoral stings. Thirteen of the 25 nominal species have serrated spines in the pectoral sting and a contrasting pigment pattern. Behavior of two saddled species, N. miurus and N. hildebrandi, and one uniformly colored species, N. leptacanthus, was investigated to test if the pigment pattern is camouflage. Saddle spacing and crypticity of the saddled species were measured against various substrates and were found to be unevenly spaced, which could be camouflage when viewed against gravel. Given substrate choices, madtoms preferred gravel during daylight conditions. In subsequent experiments, all species were given colored gravel to test color vs. texture-based substrate choice and preferred dark substrates. In the presence of a predator stimulus, madtoms preferred gravel at night and dawn. The pigment pattern likely is camouflage when viewed against gravel substrates.
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Are we preserving a "free enterprise" small business community in defense contracting?Becker, Robert Ferdinand January 1964 (has links)
Thesis (M.B.A.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / 2031-01-01
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Using Smart Scheduling to Reduce the Negative Impacts of Instrumentation-based Defenses on Embedded SystemsLe Baron, Thomas 18 April 2019 (has links)
Real-time embedded systems can be found in a large number of devices we use, including safety-critical systems. Useful for their small size and low power consumption, they are also harder to protect against state-of-the-art attacks than general purpose systems due to their lack of hardware features. Even current defenses may not be applicable since instrumentation added to defend real-time embedded systems may cause them to miss their deadlines, rending them inoperable. We show that the static properties obtained by the scheduling policies can be used as security guarantees for the tasks composing the program. By completely securing a subset of the tasks of the program only using the scheduler policy, we remove the need to add external instrumentation on these tasks, reducing the amount of extra instructions needed to entirely protect the system. With less instrumentation, the overhead added by the defenses is reduced and can therefore be applied to a larger number of systems.
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A comparative study of tissue reaction to four different suture materialsCantu, Juan A January 2011 (has links)
Photocopy of typescript. / Digitized by Kansas Correctional Industries
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Measuring Defense Support to Civil Authorities Proficiency within the National Capital RegionBrown, Kelvin 01 January 2017 (has links)
Defense Support to Civil Authorities (DSCA) is the process by which military assets can be requested by civilian authorities, often by state or regional offices of emergency management. This request is in response to critical incidents, including natural and human caused disasters. However, little is understood about collaboration and cooperation between civil authorities and their military counterparts in terms of planning and training, especially in the unique circumstance of National Capital Region (NCR) where there are local, state, and federal civil authorities and military organizations. This is problematic, as a lack of training and preparation may result in delayed response to emergency incidents in the region, which may cause a disruption of government nationwide. Using Sabatier and Jenkins-Smith's advocacy coalition framework, the purpose of this case study of DSCA in the NCR was to gain insight on whether collaborative planning and training between civil and military partners has resulted in effective public policy that will guide decision making in the event of a natural or human caused disaster. Data were collected from a total of 15 participants who represented military and civil emergency managers. These data were deductively coded consistent with the elements of the policy advocacy framework, and then subjected to thematic analysis. Findings indicated that military members have a more thorough understanding of DSCA procedures, where civilian emergency managers had knowledge deficits regarding procedures and policies guiding DSCA support. The positive social change implications stemming from this study include recommendations to civil authorities to collaborate with the Department of Defense related to mobilization procedures and DSCA policies to promote seamless cooperation in the event of a major disaster.
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Corporate Image Branding Strategies to Attract Engineering TalentMitchell, A'Shawn Lora 01 January 2019 (has links)
Aerospace and defense leaders need corporate image branding strategies to improve their attraction of engineering talent to the industry. The purpose of this single case study was to explore corporate image branding strategies leaders use at an aerospace and defense company to attract talent and increase competitive advantage. The framework for this study was the recruitment equity model. The sample population consisted of 5 marketing leaders and 5 talent acquisition leaders of an aerospace and defense company in the eastern region of the United States. The study participants had a minimum of 5 years of experience attracting engineering talent using branding strategies. Data were collected from semistructured interviews and a review of the company's talent attraction plan. The data analysis process included methodological triangulation, coding, and identifying themes. Four themes emerged: having an attractive place to work, using social media to attract talent, ensuring the mission is the basis for attracting talent, and attracting untapped talent. Findings from this study might assist aerospace and defense leaders in implementing corporate image branding strategies that close the gap of talent attraction to the aerospace and defense industry. The implications for positive social change include the potential to increase innovation and reduce national security vulnerabilities by attracting talent to the aerospace and defense industry. The business leaders of aerospace and defense will keep the industry viable by attracting top engineering talent to a workforce that is responsible for eliminating the advanced threats to the nation and its allies.
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The Study of Net Assessment on National Defense Strategic PlanningLee, Hai-Tung 13 July 2007 (has links)
Considering the significance of the Net Assessment in defining our national military strategic blueprint and operational processes, the objective of this research is to find out how to utilize Net Assessment to effectively develop the national defense strategy and to sufficiently elevate the integrated military capability for the demands in future wars.
The United States initiated the Net Assessment development in the 1970¡¦s. Net Assessment is the comparative analysis of military, technological, political, economic, and other factors governing the relative military capability of the nations. Net Assessment is used by the US Department of Defense primarily as a long term planning tool based on analysis in the competitiveness of its rival countries, and in the balance of military might. The Net Assessment provides top executives a strategic plan that corresponds to the internationally scoped situations. By taking the advantages in the resources and capabilities of the nation, this creates opportunities to fend off the emerging or future threats while improving over the deficiencies, and thus forms the strategic directions for the subsystems such as politics, economics, psychology, military, sciences and technologies. In the course of military strategic planning, the Net Assessment can be considered as the SWOT analysis technique used in the industry, that it is an essential topic for the strategic analysis for national security.
We studied the Net Assessment primarily in the scope of the national defense strategic planning. We explored the implications of the Net Assessment and its roles in the United States strategic planning through literature researches. By examining the Net Assessment in the aspects of the strategic management theories and the establishment of its processes, this revealed the relationship between the Net Assessment and the national defense strategic planning and its applications. Through the analytical studies and consolidation, one could effectively handle the analysis procedures and operations for the Net Assessment. This will fully assist the executives to understand objectively the prospect in a comprehensive and long-term view and the critical elements in the problems. While fully utilizing the functions of organizational mechanisms and operations, one could create advantageous corroborative conditions and develop defense strategies that are accurate from global vantage point such that the national security can be ultimately assured in this steadily competitive and highly variable environment.
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The Evolutionary Ecology of Stereoisomeric Sesquiterpene Lactones in Xanthium strumariumAhern, Jeffrey 13 May 2013 (has links)
The ecological factors that maintain defensive chemical variation within and between plant species have intrigued ecologists for decades. While theory posits that polymorphisms may be maintained different forms of balancing selection, relatively few experimental studies have tested whether such balancing selection can maintain defensive chemical trait polymorphisms in nature. Further, evidence demonstrating balancing selection is rare for any trait. Here, I investigated a stereochemical trait polymorphism in Xanthium strumarium. This species is polymorphic with respect to the stereochemistry of the lactone ring junction of a prominent defensive compound class ? the sesquiterpene lactones. Individual plants typically produce only cis-fused or trans-fused lactones across their entire suite of compounds. Sesquiterpene lactones are known to influence feeding behavior and growth rates of various herbivores, but nothing is known about the ecological implications of variation in this stereochemical trait. I first examined whether sesquiterpene lactone stereochemical variation can influence folivore feeding behavior in the laboratory. Using pure sesquiterpene lactones in controlled feeding experiments, I found that laboratory-reared grasshoppers were less deterred by the cis-fused compounds than the trans-fused compounds. I then found that these patterns extended to the field: in common gardens, plants producing cis-fused lactones received more damage than plants producing trans-fused lactones. Additionally, folivore damage was negatively correlated with plant fitness. Taken together, these results indicate that herbivores can impose natural selection on this stereochemical trait polymorphism in nature. Finally, I found evidence that spatially variable selection leads to fitness patterns conducive to the maintenance of this polymorphism. Further, I found that the intensity of folivore damage across spatial scales predicted in which environments each morph outperformed the other, with plants producing cis-fused lactones achieving higher fitness than plants producing trans-fused lactones when herbivore pressure was low (and the reverse being true when herbivore pressure was high). This work demonstrates that relatively minor defensive chemical variation can have far-reaching impacts on the ecology and evolution of plant populations.
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Can defense mechanisms aid in our differentiation of borderline and antisocial personalities?Presniak, Michelle D 03 September 2008
Goal: The aim of the current studies was to evaluate the ability of individual defenses to differentiate Antisocial (APD) and Borderline (BPD) personalities. Because multiple defense measures were utilized, Study 1 was dedicated to evaluating the convergent validity between the measures used: Defense Style Questionnaire (DSQ), Defense-Q, and Defense Mechanism Manual (DMM). Studies 2, 3, and 4, then evaluated the ability of the defenses to differentiate APD and BPD groups. Method: In Study 1, participants completed all defense measures and correlations were conducted between the individual defenses. In Studies 2, 3, and 4, groups of nonclinical participants were divided into APD and BPD groups based on scores from the Personality Assessment Inventory. They also completed the DSQ (Studies 2, 3, & 4), the Defense-Q (Study 3), and/or the DMM (Study 4).The groups were then examined for differences on defenses using MANOVA and DFA analyses. Results: Results from Study 1 revealed no significant correlations between the measures for any of the individual defenses. In Studies 2, 3, and 4, DSQ and Defense-Q results revealed that defenses were able to differentiate the APD and BPD groups, but the DMM results did not replicate these findings. Univariate analyses showed that many defenses differed between the groups (e.g., Acting Out, Denial, and Turning Against Self), while others showed no differences (e.g., Idealization). Conclusion: The results were discussed in relation to previous theory and research. The findings provided support for many theoretical expectations. For example, the results supported: Kernberg (1984) who posited both groups would use primitive defenses (e.g., Splitting, Denial); Perry and Cooper (1986) who posited BPD groups would internalize negative views towards the self; and Gacono and Meloy (1988) who believed Denial was characteristic of APD. Overall, the results suggested that APD and BPD groups demonstrated differences in defense use.
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Iron and reactive oxygen in wheat-pathogen interactionsGreenshields, David Lewis 31 July 2007
Iron is an essential component of various proteins and pigments for both plants and pathogenic fungi. However, redox cycling between the ferric and ferrous forms of iron can also catalyse the production of dangerous free radicals and iron homeostasis is therefore tightly regulated. During pathogen attack, plants quickly produce large amounts of reactive oxygen species at the site of attempted pathogen ingress. This so-called oxidative burst has received considerable attention, but no single enzyme has been shown to account for the phenomenon. Using inductively coupled plasma mass spectrometry and histochemistry, I show that iron is secreted to the apoplast of the diploid wheat <i>Triticum monococcum</i> during attack by the powdery mildew fungus <i>Blumeria graminis</i> f.sp. <i>tritici</i>. This iron accumulates at cell wall appositions synthesised de novo beneath sites of pathogen attack. I further show, using histochemistry and pharmaceutical inhibitors, that this apoplastic iron accumulation is required for production of H2O2 in the oxidative burst. To understand the impact of this massive change in iron homeostasis on gene transcription, I employ a 187 gene targeted macroarray platform and establish that iron overload induces the expression of iron homeostasis-related genes and defence-related genes through iron itself and iron-mediated H2O2 production, respectively. To illustrate how the plant is able to withstand the negative effects of its own oxidative defences, I characterise a novel quinone redox cycle, and show that simultaneous induction of a protective quinone reductase isoform and downregulation of reactive oxygen-producing quinone reductase isoform prevents the spread of reactive oxygen during pathogen attack. Finally, in an effort to understand the impact of iron on fungal pathogenicity, I investigate iron uptake in the head blight pathogen, <i>Fusarium graminearum</i>. Fungi use at least two separate systems to take up iron, one based on enzymatic iron reduction and the other based on the synthesis and secretion of small iron chelators termed siderophores. Using mutants disrupted in either of two modes of iron uptake, I establish that siderophore production is essential for full F. graminearum virulence on wheat. This thesis exposes iron as an important component of both plant defence and fungal virulence.
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