Exploring complex chemical systems: insights from mass spectrometry, electrochemistry and continuous cell culture

The work presented herein covers a broad range of research topics and so, in the interest of clarity, has been presented in a portfolio format. Accordingly, each chapter consists of its own introductory material prior to presentation of the key results garnered, this is then proceeded by a short discussion on their significance. In the first chapter, a methodology to facilitate the resolution and qualitative assessment of very large inorganic polyoxometalates was designed and implemented employing ion-mobility mass spectrometry. Furthermore, the potential of this technique for ‘mapping’ the conformational space occupied by this class of materials was demonstrated. These claims are then substantiated by the development of a tuneable, polyoxometalate-based calibration protocol that provided the necessary platform for quantitative assessments of similarly large, but unknown, polyoxometalate species. In addition, whilst addressing a major limitation of travelling wave ion mobility, this result also highlighted the potential of this technique for solution-phase cluster discovery. The second chapter reports on the application of a biophotovoltaic electrochemical cell for characterising the electrogenic activity inherent to a number of mutant Synechocystis strains. The intention was to determine the key components in the photosynthetic electron transport chain responsible for extracellular electron transfer. This would help to address the significant lack of mechanistic understanding in this field. Finally, in the third chapter, the design and fabrication of a low-cost, highly modular, continuous cell culture system is presented. To demonstrate the advantages and suitability of this platform for experimental evolution investigations, an exploration into the photophysiological response to gradual iron limitation, in both the ancestral wild type and a randomly generated mutant library population, was undertaken. Furthermore, coupling random mutagenesis to continuous culture in this way is shown to constitute a novel source of genetic variation that is open to further investigation.

The links between head injury and homelessness: A qualitative study

Background and aims: Head injury (HI) is a cause of cognitive impairment within the homeless population (Hwang et al, 2008). One study reported that over a 30-year period, the prevalence of hospitalised HI was 5.4 times higher in the homeless than in the general population (McMillan et al, 2015). This study explores the perceptions of homeless adults who have sustained a HI and their views regarding the relevance of HI to their homeless status. Methods: Participants were seven homeless adults with a moderate or severe HI. They were asked to talk about their journey to homelessness and in particular, to reflect on any perceived links between HI and their homeless status. The data were analysed using Interpretative Phenomenological Analysis (IPA). Results and conclusions: Emerging themes included: impairment following HI; substance misuse, feeling let down by services and difficult relationships with family. Evidence for the role of HI in precipitating and maintaining homelessness was found. Despite this, co-morbid difficulties complicate the picture. Four out of seven participants viewed substance misuse as their primary difficulty. This illustrates the need for in-depth assessment within this population in order to ensure that difficulties are fully understood and that the correct supports/ interventions are offered.