Chicano identity and discourses of supplementarity on Mexican cinema: from ‘The Man Without a Fatherland’ (Contreras Torres: 1922) to ‘Under the Same Moon’ (Riggen: 2008)

A radical change took place in Mexican narratives of belonging during the 1990s, when NAFTA was first negotiated. Narratives of migration drastically changed the status of Mexican migrants to the US, formerly derided as ‘pochos’, presenting them as model citizens instead. Following Derrida, I argue the role of the migrant became that of a supplement, which is, discursively, at the same time external to and part of a given unit, standing for and allowing deeper transformations to take place in the whole discourse of bilateral relations and national identity more generally. I use Derrida’s concept of the supplement to discuss changing representations of Chicanos in Mexican cinema, and to assess the extent that they have succeeded in reframing the discourse on national identity, with a focus on gender.

The role of bacterial interspecies communication in polymicrobial infection of the cystic fibrosis lung

There is an increasing appreciation of the polymicrobial nature of bacterial infections associated with Cystic Fibrosis (CF) and of the important role for interactions in influencing bacterial virulence and response to therapy. Patients with CF are co-infected with Pseudomonas aeruginosa, Burkholderia cenocepacia and Stenotrophomonas maltophilia. These latter bacteria produce signal molecules of the diffusible signal factor (DSF) family, which are cis-2-unsaturated fatty acids. Previous studies showed that DSF from S. maltophilia leads to altered biofilm formation and increased tolerance to antibiotics in P. aeruginosa and that these responses require the P. aeruginosa sensor kinase PA1396. The work in this thesis aims of further elucidate the influence and mechanism of DSF signalling on P. aeruginosa and examine the role that such interspecies signalling play in infection of the CF airway. Next generation sequencing technologies targeting the 16S ribosomal RNA gene were applied to DNA and RNA isolated from sputum taken from cohorts of CF and non-CF subjects to characterise the bacterial community. In parallel, metabolomics analysis of sputum provided insight into the environment of the CF airway. This analysis revealed a number of observations including; that differences in metabolites occur in sputum taken from clinically stable CF patients and those with exacerbation and DNA- and RNA-based methods suggested that a strong relationship existed between the abundance of specific strict anaerobes and fluctuations in the level of metabolites during exacerbation. DSF family signals were also detected in the sputum and a correlation with the presence of DSFproducing organisms was observed. To examine the signal transduction mechanisms used by P. aeruginosa, bioinformatics with site directed mutagenesis were employed to identify signalling partners for PA1396. A pathway suggesting a role for a number of proteins in the regulation of several factors following DSF recognition by PA1396 were observed.