Ontogenetic niche shifts generally coincide with changes in size, morphology, behavior, and/or feeding preferences during development, resulting in a shift in preferred habitat. In aquatic species, these ontogenetic niche shifts are often associated with habitat-dependent changes in competition and/or predation dynamics, expressed as a size-depth relationship where the larger-bodied adults occupy deeper habitats while the smaller-bodied juveniles primarily reside in shallower regions. While the influence of interspecific interactions on size-structured habitat occupancy has been well studied, few have examined the potential role of intraspecific agonistic interactions between size classes in ontogenetic niche shifts. A simulation model was developed to test whether the size-specific habitat occupancy observed in signal crayfish can be explained by the size-structured individual responses to agonistic interaction, where the smaller-bodied juvenile responds to the interaction with an escape movement, to avoid engagement and the risk of mortality or injury from the adult. The simulated movements of signal crayfish resulted in higher juvenile occupancy of riffles relative to pools reflecting a greater rate of escape from adults into riffles, away from the higher densities of adults in their preferred habitat (i.e. pools). This provides evidence that the juvenile escape response to size-structured, intraspecific, agonistic interactions may contribute to ontogenetic niche shifts.

The point of departure for this study is the meeting-place between an author and his times. Both in his youth and in later years, August Strindberg was in bitter conflict with the Swedish Establishment. At the turn of the century, however, when the fifty-year-old author returned to Stockholm after many years of exile, he was able to be accepted by the cultural community in the country of his birth. This fact is studied here both from the point of view of a change in Strindberg's own attitudes, and of the changes that had taken place in Sweden during the author's exile. In the early 1880s, Strindberg had challenged accepted truths by writing a work of considerable proportions dealing with the history of the Swedish people, this in conscious opposition to the established view of history which was primarily concerned with the history of its monarchs, Strindberg was criticised both by the Press and by history scholars, and the reaction contributed to his decision to leave the country. By the turn of the century, considerable changes had taken place. Sweden had become an industrialized country, and the emerging middle class had made its mark on the philo­sophy of the time and also gained control of the organs of public opinion. Because Strindberg only wrote plays at this time, a considerable amount of attention is given in the dissertation to the development of the Stockholm theatre. Privately-owned theatres had now come to replace the earlier Royal theatre monopoly. On his return, Strindberg set about writing historical dramas. He was now willing to cater to the conservative views that he had fought against twenty years previously. He wrote of the Swedish monarchs and tried to satisfy the demands of an earlier period for dramas with historical facts that were completely correct. In the autumn of 1899 while he was busy writing "Gustaf Adolf " (Gustavus Adolphus), his recently-completed plays "Gustaf Vasa" and "Erik XIV" were being performed at the Svenska teatern in Stockholm. It now became apparent that the majority of critics regarded esthetic considerations as being more important than those of historical accuracy, and that they also prefered to see the monarchs portrayed as psychologically credible figures rather than as impersonal, glorified hero figures. Only the most conservative critics failed to hold this view. Despite the resounding success of both "Gustaf Vasa" and "Erik XIV", Strindberg tried in his new play to cater even to his few adversaries. He engaged in deep historical studies and peppered the play with historical details, resulting in a play that is inordi­nately long and very difficult to manage. However, concerning the main character, Strindberg was unable to pander to con­servative criticism. Fundemental artistic characteristics reemerged and transformed the 17th century monarch into a problematic individual who undergoes a personal develop­ment, laboriously seeking the right road. He has to battle with religious intolerance, his role as monarch, his understanding of the world, and his personal dreams of power. When "Gustaf Adolf" appeared in the bookshops in autumn 1900, the critics were unanimous in the belief that Strindberg had succeeded in his depiction of history. On the other hand, many felt that he had degraded the hero-king by giving him personal problems / digitalisering@umu

The thesis Is concerned with the development of a separately excited DC machine In which gate turn-off thyristor devices with their associated firing and protective circuits are used to provide the static commutation of armature coil current. The developed machine has Its armature winding with 24 tapping points located on the stator and Interconnected In "Lop" configuration. The Initiation of the conduction periods of armature switching devices Is defined by a digital control logic circuit. In conjunction with an Incremental rotary encoder which provides the necessary feedback Information relating to shaft speed and shaft angular position. This Is arranged such that, under normal running conditions of the machine, the axis of the radial field of the armature winding maintains the normal space-quadrature relationship with that of the main field winding, giving the optimal torque angle of 000. Provision Is made, however, within the digital control circuit for controlled departure of the armature switch tapping points from the quadrature axis positions, and the effect of this, In Improving commutation Is Investigated. The effect of Interpoles Is also explored. On the basis of the analysis carried out, a proposal Is made for the future development of the machine employing a reduced number of armature switching devices without the need for Interpole windings.

Zugl.: Oestrich-Winkel, Europ. Business School, Diss., 2006.

Zugl.: Siegen, Univ., Diss., 2007

Zugl.: Hannover, Univ., Diss., 2008

Bachelor-Arbeit Univ. St. Gallen, 2005.

Bachelor-Arbeit Univ. St. Gallen, 2004.

Diss. Nr. 2979 Wirtschaftswiss. St. Gallen, 2004. / Literaturzverz.

Master-Arbeit Univ. St. Gallen, 2008.