Doctor of Philosophy / Dingo Media examines the development of media events using as a case study one of Australia’s most widely known criminal investigations, the disappearance of Azaria Chamberlain at “Ayers Rock”. Considering the case as a blueprint for the way mass media events develop and evolve in the late capitalist era, this thesis suggests that the event marks a turning point in negotiation of the public sphere and Australian national identity. Using an original model, I trace from the 1980s five phases through which news stories pass in their evolution as modern media events by comparing the Chamberlain saga to contemporary cases involving “controversial” women, Schapelle Corby, Joanne Lees and Pauline Hanson. The first phase examines the emerging practice of news workers focusing on personalities rather than events; the second phase analyses both the formation of counter-publics protesting the conviction, and the development of a dialogic connection between media and publics; the third phase investigates the rise of a modern celebrity industry promoting “ordinary” individuals into subjects of media discourse; the fourth phase considers the process of mythic production surrounding the Chamberlain case as related to processes of nation-building in the late 1980s; finally, the fifth phase critiques the prevalent view that, through continual retelling, the event has suffered a loss of meaning. Axiomatic to this study will be the politics of representation, how the media records, organises and mythologises information, as well as the interaction between texts and audiences.

Doctor of Philosophy / Dingo Media examines the development of media events using as a case study one of Australia’s most widely known criminal investigations, the disappearance of Azaria Chamberlain at “Ayers Rock”. Considering the case as a blueprint for the way mass media events develop and evolve in the late capitalist era, this thesis suggests that the event marks a turning point in negotiation of the public sphere and Australian national identity. Using an original model, I trace from the 1980s five phases through which news stories pass in their evolution as modern media events by comparing the Chamberlain saga to contemporary cases involving “controversial” women, Schapelle Corby, Joanne Lees and Pauline Hanson. The first phase examines the emerging practice of news workers focusing on personalities rather than events; the second phase analyses both the formation of counter-publics protesting the conviction, and the development of a dialogic connection between media and publics; the third phase investigates the rise of a modern celebrity industry promoting “ordinary” individuals into subjects of media discourse; the fourth phase considers the process of mythic production surrounding the Chamberlain case as related to processes of nation-building in the late 1980s; finally, the fifth phase critiques the prevalent view that, through continual retelling, the event has suffered a loss of meaning. Axiomatic to this study will be the politics of representation, how the media records, organises and mythologises information, as well as the interaction between texts and audiences.

Im Fokus dieser Arbeit stand die Analyse von Faktoren, die den Zusammenbau des Flagellenapparates von Legionella pneumophila (Lp) regulieren. Mit einem kombinierten Replikations-/ Überlebensversuchs mit Lp Corby oder Lp Paris und ihren zugehörigen Regulationsmutanten wurde eine verminderte Fitness für dfliA und erstmals für drpoN, dfleQ defiziente Stämme nachgewiesen. Zur Validierung von Microarray-Daten aus Lp Paris wurden wachstumsphasenabhängige Transkriptions- und Translationsanalysen mit Lp Corby Wildtyp und drpoN, dfleQ, dfliA und dflaA defizienten Stämmen durchgeführt. Es wurde gezeigt, dass die basale Expression von fliA in den späteren Phasen unabhängig von RpoN und FleQ stattfindet. In dieser Arbeit konnte erstmals der Transkriptionsstartpunkt des Hauptregulators FliA bestimmt werden. Es zeigte sich eine putative RpoD (S70) Bindungsstelle. Ein Modell zur Regulation der fliA Expression wurde weiterentwickelt. Demnach kommt es in der exponentiellen Phase durch das Zusammenwirken von RpoD und DksA, aber unabhängig von FleQ, zur basalen fliA Promotoraktivität. Durch den Übergang in die transmissive Phase und direkte oder indirekte Interaktion mit FleQ sowie dem Alarmon ppGpp scheint es zu einem Austausch des Sigmafaktors S70 gegen SS und zu einer Aktivierung der fliA Expression zu kommen. Elektronenmikroskopische Studien zeigten, dass drpoN und dfleQ defiziente Mutanten wahrscheinlich aufgrund des fehlenden Basalkörpers nicht flagelliert sind. Mutanten für dfliA, dflaA und dfliD hatten ebenfalls keine Flagelle, zeigten aber eine ungewöhnliche, gerade Hook Struktur, die den Zusammenbau des Basalkörpers demonstriert. Weiterhin wurden durch in silico Studien 15 Legionella Spezies in Bezug auf das Flagellensystem und ein putatives Chemotaxissystem untersucht. So konnte L. oakridgensis als erste Art ohne beide Systeme sequenziert werden. Andererseits konnten mit LLAP12, L. bozemanii, L. gormanii und L. lytica Stämme beschrieben werden, die beide Systeme tragen. / This work focused on the analysis of factors contributing to the regulation of the flagellum self-assembly of Legionella pneumophila (Lp). With a combined replication/survival assay with Lp Corby or Lp Paris and their corresponding regulatory mutants a reduced fitness could be verified for dfliA and for the first time for drpoN, dfleQ deficient strains. For validation of microarray-data for Lp Paris with strain Lp Corby a growth phase dependent analysis of transcription and translation rates was done with wild-type and the drpoN, dfleQ, dfliA and dflaA deficient strains. A regulation of basal fliA expression independently from RpoN and FleQ was shown in the later growth phases. Furthermore the transcriptional start site of fliA could be shown for the first time. A RpoD (S70) binding site could be identified. According to a further developed model for the regulation of the fliA expression RpoD and DksA lead to a basal fliA promotor activity, independently from FleQ. Most likely, during transition to stationary phase, direct or indirect interaction with FleQ and the alarmone ppGpp results in the exchange of the sigma factor S70 and the binding of RpoS. This leads to the activation of fliA expression. Electron microscopic studies revealed that drpoN and dfleQ deficient mutants are not flagellated caused by the missing basal body. Mutants of dfliA, dflaA and dfliD were also aflagellated, but there was a uncommon straight hook structure visible which demonstrates a filament-independent assembly of the basal body. Furthermore, in silico analysis was done with 15 Legionella species with regard to the flagellum regulation system and a putative chemotaxis system. Analysis revealed that the strain L. oakridgensis is the first strain lacking both systems. On the other hand the strains LLAP12, L. bozemanii, L. gormanii and L. lytica could be characterized as strains carrying both systems.