Analyse der Landschaftszerschneidung und -fragmentierung, Untersuchung und Anwendung verschiedener Zerschneidungsgeometrien und deren Implementierung für unterschiedliche Indikatoren. Die Ergebnisse des methodischen Vergleiches für den Landkreis Havelland sollen die Grundlage für die Auswahl der geeignetesten Methode bei einer landesweite Untersuchung in Brandenburg liefern. / Analysis of landscape fragmentation and dissection using different dissection geometries and application to different indicators. The comparison of different methods for the Havelland county will be used as the base to choose the best method for a statewide analysis in Brandenburg.

This dissertation aims to improve our understanding of how dams and reservoirs impact freshwater systems worldwide. The following questions were addressed specifically: 1) what are the spatial patterns and magnitudes of flow regulation and channel fragmentation by dams globally; 2) how are dam impacts distributed biogeographically, and which are the biogeographic regions and taxa most threatened by dam impacts; and 3) how can climate change and dams be expected to interact in basins, and what management actions would mitigate adverse interactions? Results show that the majority of the world’s large river systems are fragmented and have their flow altered by dams. Exceptions to this tend to lie in regions inhospitable to hydropower development, such as northern tundra, or in the least economically active regions. The biogeographic distribution of dam impact is widespread, both at terrestrial and freshwater scales, representing significant threat to global biodiversity. Relatively species-poor tundra is the world’s only terrestrial ecoregion which remains predominantly unaffected by dams. Nearly half of the world’s freshwater ecoregions are internally fragmented by dams, and ecoregional distinctions may be artifically imposed by dams in many cases. Freshwater ecoregions with the highest counts of total and endemic species remain relatively unobstructed, representing significant conservation potential. Diadromy is one of the few fish traits indicative of vulnerability to dams for which data are sufficient for global scale analysis. Lampreys (Lampetra spp.), Eels (Anguilla spp.) and Shad (Alosa spp.) are examples of genera particularly vulnerable to dams because their distributions coincide with the most heavily fragmented freshwater ecoregions, and a large proportion of the coincident species for each genera are diadromous. Due to changes in discharge and water stress, the area of large river basins in need of management interventions to protect ecosystems or people will be much greater for basins impacted by dams than for basins with free-flowing rivers. Proactive measures that restore the natural capacity of rivers to buffer climate-change impacts are more desirable than reactive actions since they may also lead to environmental benefits such as higher water quality and restored fish populations – benefits which may later be unattainable.

<p>The objective of this project is to study the production of Li, Be and B isotopes emitted in the interaction of 12C with 12C at incident energies of 200 and 400 MeV.<br /> The energies of these produced fragments were measured with a detector telescope consisting of two silicon detectors at the incident energy of 200 MeV while a third silicon detector was added for the measurements at 400 MeV.</p>

Bioinformatic methods were developed for improved identification of endogenous peptides using mass spectrometry. As a framework for these methods, a database for endogenous peptides, SwePep, was created. It was designed for storing information about endogenous peptides including tandem mass spectra. SwePep can be used for identification and validation of endogenous peptides by comparing experimentally derived masses of peptides and their fragments with information in the database. To improve automatic peptide identification of neuropeptides, targeted sequence collections that better mimic the peptidomic sample was derived from the SwePep database. Three sequence collections were created: SwePep precursors, SwePep peptides, and SwePep predicted. The searches for neuropeptides performed against these three sequence collections were compared with searches performed against the entire mouse proteome, and it was observed that three times as many peptides were identified with the targeted SwePep sequence collections. Applying the targeted SwePep sequence collections to identification of previously uncharacterized peptides yielded 27 novel potentially bioactive neuropeptides. Two fragmentations studies were performed using high mass accuracy tandem mass spectra of tryptic peptides. For this purpose, two databases were created: SwedCAD and SwedECD for CID and ECD tandem mass spectra, respectively. In the first study, fragmentation pattern of peptides with missed cleaved sites was studied using SwedCAD. It was observed that peptides with two arginines positioned next to each other have the same ability to immobilize two protons as peptides with two distant arginines. In the second study, SwedECD was used for studying small neutral losses from the reduced species in ECD fragmentation. The neutral losses were characterized with regard to their specificity and sensitivity to function as reporter ions for revealing the presence of specific amino acids in the peptide sequence. The results from these two studies can be used to improve identification of both tryptic and endogenous peptides. In summary, a collection of methods was developed that greatly improved the sensitivity of mass spectrometry peptide identification.

This thesis focuses on one of the most appreciated products of the Turkish Television, the TV Series&#039 / production and labor process. Starting from the fact that the production side of this highly attention gathering media product hasn&#039 / t received too much academic concern, by analyzing the workers of the sector, this point is tried to be illuminated. This thesis that analyzes TV series&#039 / working conditions in the perspective of &ldquo / precarious employment&rdquo / departing from this framework, argues the workers of the industry are fragmented into two groups, &ldquo / creative&rdquo / and &ldquo / technical&rdquo / workers. In this context it indicates the creative workers not only as not being affected from the precarious employment conditions too much but also as the executor of the technical workers&#039 / experience of precariousness in the production level.

After 1950, Turkey had adopted comprehensive urban planning methodologies within the competence of a unique central authority. By 1980s, localization policies were introduced and local administrations had been authorized for planning issues. But this political turn could not continue effectively, because of dispersed sectoral policies have gained the leading role in decision making, creating the fragmentation problem. Administrative competences in different central bodies, especially in the sectoral ministries, have weakened the local decision mechanisms. This thesis will try to present a critical analysis of the aforementioned process aiming to provide the pros and cons of the multiple planning policies.

Loss of biodiversity is one of the most severe threats to the ecosystems of the world. The major causes behind the high population and species extinction rates are anthropogenic activities such as overharvesting of natural populations, pollution, climate change and destruction and fragmentation of natural habitats. There is an urgent need of understanding how these species losses affect the ecological structure and functioning of our ecosystems. Ecological communities exist in a landscape but the spatial aspects of community dynamics have until recently to large extent been ignored. However, the community’s response to species losses is likely to depend on both the structure of the local community as well as its interactions with surrounding communities. Also the characteristics of the species going extinct do affect how the community can cope with species loss. The overall goal of the present work has been to investigate how both local and regional processes affect ecosystem stability, in the context of preserved biodiversity and maintained ecosystem functioning. The focus is particularly on how these processes effects ecosystem’s response to species loss. To accomplish this goal I have formulated and analyzed mathematical models of ecological communities. We start by analyzing the local processes (Paper I and II) and continue by adding the regional processes (Paper III, IV and V). In Paper I we analyze dynamical models of ecological communities of different complexity (connectance) to investigate how the structure of the communities affects their resistance to species loss. We also investigate how the resistance is affected by the characteristics, like trophic level and connectivity, of the initially lost species. We find that complex communities are more resistant to species loss than simple communities. The loss of species at low trophic levels and/or with high connectivity (many links to other species) triggers, on average, the highest number of secondary extinctions. We also investigate the structure of the post-extinction community. Moreover, we compare our dynamical analysis with results from topological analysis to evaluate the importance of incorporating dynamics when assessing the risk and extent of cascading extinctions. The characteristics of a species, like its trophic position and connectivity (number of ingoing and outgoing trophic links) will affect the consequences of its loss as well as its own vulnerability to secondary extinction. In Paper II we characterize the species according to their trophic/ecological uniqueness, a new measure of species characteristic we develop in this paper. A species that has no prey or predators in common with any other species in the community will have a high tropic uniqueness. Here we examine the effect of secondary extinctions on an ecological community’s trophic diversity, the range of different trophic roles played by the species in a community. We find that secondary extinctions cause loss of trophic diversity greater than expected from chance. This occurs because more tropically unique species are more vulnerable to secondary extinctions. In Paper III, IV and V we expand the analysis to also include the spatial dimension. Paper III is a book chapter discussing spatial aspects of food webs. In Paper IV we analyze how metacommunities (a set of local communities in the landscape connected by species dispersal) respond to species loss and how this response is affected by the structure of the local communities and the number of patches in the metacommunity. We find that the inclusion of space reduces the risk of global and local extinctions and that lowly connected communities are more sensitive to species loss. In Paper V we investigate how the trophic structure of the local communities, the spatial structure of the landscape and the dispersal patterns of species affect the risk of local extinctions in the metacommunity. We find that the pattern of dispersal can have large effects on local diversity. Dispersal rate as well as dispersal distance are important: low dispersal rates and localized dispersal decrease the risk of local and global extinctions while high dispersal rates and global dispersal increase the risk. We also show that the structure of the local communities plays a significant role for the effects of dispersal on the dynamics of the metacommunity. The species that are most affected by the introduction of the spatial dimension are the top predators.

In the present thesis, Jane and Louisa Will Soon Come Home, the novel by the Jamaican writer Erna Brodber, is analyzed in the context of post-colonial identity trauma. Analyzing the complex organizational and narrative structure of the novel, the essay author studies how the novel’s rhythmicity and the broken narrative portray the protagonist’s identity fragmentation. Drawing on the work’s connection to the ring game played in the Caribbean and applying the symbolism of the Caribbean folk rhythms, the essay author discusses the subversive intent of Brodber’s novel and her method of rewriting the past as a way of recovering one's identity.

The objective of this research is to enhance the network performance under realistic mobile ad-hoc networks environments without modification of the standard. Overview of this research is summarized as follows: First, a packet-fragmentation technique to improve network throughput under the worst channel conditions is proposed. While the conventional packet-fragmentation technique research focuses only on random-bit errors, the proposed technique employs both random bit errors and hidden-node collisions. The analytical models based on Markov-chain model shows that the optimal fragmentation technique can effectively reduce the number of retransmissions caused by both collisions from hidden nodes and corrupted packets by random bit errors, and eventually improving throughput in noisy VANETs channels. As a second contribution, a dynamic service-channel allocation (DSCA) scheme is proposed to maximize the network throughput by dynamically assigning different service channels to the users. The theoretical analysis in this thesis will consider wireless access in the vehicular environment (WAVE) protocol, which is the main characteristic of the vehicular ad-hoc networks standard (the IEEE 802.11p). To summarize, the main contribution of this research is that two schemes will improve the network throughput significantly without modification of the standard. Therefore, there is no implementation issue to deploy the proposed schemes in real devices.

Le micro-écaillage désigne le phénomène de ruine par fragmentation d'un matériau fondu en partie ou complètement suite au passage d'une onde de choc intense et brève. Les lasers sont utilisés comme générateurs de choc à des fins scientifiques et industrielles. Ils se trouvent à la base de la recherche sur la fusion nucléaire par confinement inertiel. Dans ce contexte, la production de fragments à hautes vitesses par micro-écaillage peut endommager les installations dans lesquelles les expériences de choc sont menées. Les travaux de thèse, réalisés à l'Institut P' en collaboration avec différentes équipes du CEA, visent la compréhension et la modélisation de tous les processus mis en jeu dans le phénomène de micro-écaillage, dans le but de prévoir les risques encourus par les installations. Des expériences visant à étudier le micro-écaillage de cibles d'étain et d'aluminium soumises à des chocs laser ont été réalisées au Laboratoire pour l'Utilisation des Lasers Intenses. Divers diagnostics complémentaires (Vélocimétrie Hétérodyne, récupération des éjectas, microtomographie) ont permis de caractériser les propriétés balistiques (distributions de tailles et de vitesses) des fragments composant le nuage micro-écaillé. En parallèle, des modèles de changements de phase et de fragmentation ont été adaptés pour simuler le micro-écaillage. Ces modèles ont été implantés dans un code de calcul pour prédire les tailles et les vitesses des débris générés dans les cibles d'étain et d'aluminium. L'association des résultats numériques issus de ces simulations et des résultats expérimentaux a permis la caractérisation des différentes étapes du micro-écaillage.