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Thesis (M.A.)--Boston University

Thesis (MA)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

Food webs consist of a combination of bottom-up (resource-driven) and top-down (predator-driven) effects. The strength of these effects depends on the context in which they occur. I investigated food web (trophic) relationships between wolf (Canis lupus) predation, elk (Cervus elaphus) herbivory, aspen (Populus tremuloides Michaux) recruitment, and fire. The study setting, in the central portion of the Crown of the Continent Ecosystem, spans the US/Canada border and encompasses Glacier National Park (GNP), Montana and Waterton Lakes National Park (WLNP), Alberta. I stratified my observations across three spatially distinct areas, the North Fork Valley, in the western portion of GNP; the Waterton Valley, in the eastern portion of WLNP; and the Saint Mary Valley, in the eastern portion of GNP. All valleys are elk winter range (low-lying grasslands with patches of aspen). The valleys have three different observed wolf population levels (Saint Mary: low; Waterton: moderate; North Fork: high), which represent three levels of long-term predation risk (the probability of an elk encountering a wolf). Ecological characteristics (e.g., climate, soils, elevation, plant associations) are comparable among valleys. Fire has occurred in 90% of the North Fork. My objective was to examine the relative influence of bottom-up (fire) and top-down (predation risk) factors and the context-dependence of these relationships via data gathered during a three-year time span. I found complex elk responses to bottom-up and top-down factors that could influence habitat use by elk. Pellet transect data demonstrated that elk exhibited the same risk reduction behavior at all wolf population levels, even at very low levels. Predation risk variables that provided impediments to detecting or escaping wolves had a similar and negative influence on occurrence of elk (pellet piles), regardless of wolf population density. Fire had a negative effect on elk density and a positive effect on wolf density (per scat piles) in aspen communities where a high wolf population existed. Aspen cover, which may be riskier than open grassland, also had a negative effect on elk density, except at very high wolf levels without fire. The risk of wolf predation alone did not drive elk behavior. Conversely, focal animal (elk vigilance behavior) data suggested a positive relationship between wolf population and elk vigilance. However, when I deconstructed vigilance, elk demonstrated complex, context-dependent adaptive behavior in response to the long-term risk of predation by wolves. Commonly identified drivers of elk vigilance (group size, impediments to wolf detection and escape) appeared to be important drivers at an intermediate level of long-term predation risk (e.g., Waterton). These drivers ceased to function in this manner when the long-term predation risk level increased (The North Fork). At high levels of long-term predation risk, vigilance was high, but not driven by these common factors. In some cases, the relationship between vigilance and risk factors was reversed (e.g., group size). And at a low level of long-term predation risk (Saint Mary), elk did not respond to these drivers of vigilance. When I measured aspen demography (browse, recruitment), browse was lower in the North Fork, where there was a high wolf population, suggesting a top-down effect. However, I found low aspen recruitment in the absence of fire in all valleys, which indicates a bottom-up effect in that aspen is highly fire-dependent. Top-down predictors of aspen recruitment (e.g., plot position and stand size, which are related to predation risk) had no effect on browse levels regardless of wolf population level. In sum, the risk of wolf predation alone did not drive the food web relationships I observed. Bottom-up and top-down forces worked together in valleys that contained well-established wolf populations, and to a lesser degree in a valley with a low wolf population. Commonly used measures of predation risk responses (e.g., vigilance) reversed their relationship as the wolf population increased. Low aspen recruitment in the absence of fire demonstrates the importance of bottom-up effects. Bottom-up and top-down effects may be important joint engineers of aspen communities. My findings invite deeper inquiry into the interaction between bottom-up and top-down effects in large mammal systems. / Graduation date: 2012

(anglický jazyk) The purpose of this thesis is to clarify the activities of United Nations' peacekeep-ing operations and thus provide an answer to the question of how and with what results they contribute to providing international peace and security. The work deals with peace-keeping operations appointed under UN Security Council resolutions. I chose this topic because of the great importance of peacekeeping operations status within UN activities and because of the interest in clarifying the role of their impact on world peace and security. This thesis is composed of five chapters. The first one deals with the role of the United Nations and its position within the international peace and security. The second chapter focuses on the definition of basic terminology that most often occurs in relation to the characteristics of UN peacekeeping operations and distinguishes them from each other. The third chapter defines their types and provides the role of peacekeeping operations by showing the essential characteristics of their development, mandate, and working princi-ples. The fourth chapter presents the issue of formation of the peacekeeping operation start-ing with the process of its establishment, continuing with the law applicable to the opera-tion, ending with its financing. The fifth chapter...

Thesis (Ph. D.)--Indiana University, 1991. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 1049-1074).

Thesis (Ph. D.)--Indiana University, 1991. / Includes bibliographical references.

Thesis (Ph. D.)--Indiana University, 1991. / Vita. Includes bibliographical references (leaves 1049-1074).

Student Number : 0400454M - MA research report - School of Social Sciences - Faculty of Humanities / The debate about the legality and legitimacy of third party intervention in the “domestic” affairs of sovereign states has been ongoing. This research focuses on the intervention by Economic Community of West African States (ECOWAS) in the Sierra Leone conflict. The research inquires into the legality and legitimacy of the intervention, against the backdrop of existing international law prohibition on the use of force, and the principle of non-intervention in the domestic affairs of sovereign states. An analysis of the emerging trend of humanitarian intervention and the current emphasis on human security is made in order to determine whether the intervention in Sierra Leone fits into this paradigm. While acknowledging the importance of states in international relations, this study inquires into the shift of security from “state centric” to “people centric”. This study makes a case for sustained efforts in the area of intervention on humanitarian grounds. It further argues that regional organizations should have a pre-emption right to intervene in conflicts that affect their regions of influence. However, the study also recognizes that this concept might be subject to abuse by powerful nations if not well managed. The study therefore recommends the importance of a well articulated framework that will serve as a standard for future interventions.

The thesis analyses the systems, dynamics and conditions of international cooperation/non-cooperation in the international community that is embodied through international/regional institutions and organisations. As Robert Cooper describes, the international community consists of the three worlds in which the differences between them may be confrontational in international cooperation. While the post-modern civilisation and values are introduced into the institutions and organisations for international peace and security, the state actors from the pre-modern and modern civilisations and values are vigorously defending the traditional version of state sovereignty. Then, all these are equally the member of the international community and, as Robert Axelrod's Prisoner Dilemma game sets, neither state actors nor structural actors of international relations can escape from it. Therefore, it is hoped that, as Axelrod's theory suggests, the closed community, in the end, produces cooperation and a positive peace for a better future for all. In the case studies, the OSCE faces a number of non-cooperative state actors, like Russia. An anti-OSCE civilisation exists and is resisting the organisational values, while it is staying in the framework. Thus, the organisation is suffering from defectors and free-riders. Knowing the limitation of the organisation, it still has a space for improvement and a useful function which is to provide a long term process to make a non-cooperate actor cooperative.