This research adopts a critical realist methodology to gain explanatory insight into the job retention challenges faced by employees recovering from mental health problems. Methods involved a literature review of qualitative job retention research, a comparative case study approach, and service user collaboration. Occupational, resilience and mental health recovery perspectives were the major orientating concepts. One case study comprised seven employed people who were using acute mental health services. The second comparative case study comprised fourteen users of a community- based job retention project for employed people with mental health problems. All twenty- one participants took part in individual interviews following a semi-structured format. The data were analysed within a critical realist paradigm using a combination of inductive and deductive thematic and constant comparative analysis. Work mattered to people during recovery because of feelings of guilt about not working, and because some feared that work had, or could, exacerbate their mental health problems. Such fears co-existed with a strong sense that work was an important part of people's lives in terms of finance, social capital, occupational capital (a concept newly proposed in this thesis) and personal capital. These assets were under threat, but they also had the potential to be deployed to support recovery. Participants were on complex and uncertain return-to-work journeys, facing a combination of internal and external obstacles. Barriers arose from the direct impacts of mental health problems, external and internalised stigma, job demands and the workplace environment - particularly relationships with colleagues and, above all, managers. The concept of iatrogenesis here is newly applied to being on sick leave, conceived of as an otherwise necessary therapeutic measure which brings with it additional challenges, risking delay to recovery and return to work. Findings suggest that return-to-work trajectories are likely to be more successful and sustainable when such challenges are addressed. The implications for practice and policy drawn out in this research are related to keeping in touch with work; mitigating the iatrogenic effects of sick leave; maintaining work orientation and identity; return-to-work planning; and harnessing 'natural', specialist and peer supports. Broader implications were that occupational and resilience perspectives can be integrated to help understand the challenges people with mental health problems encounter when seeking to retain employment. This, in turn, lent support to a social critique which called for work to be organised in a way that is centred on people's needs and well-being, and not just economic efficiency.

14-3-3 proteins are a ubiquitous family known for their ability to regulate myriad cellular processes including lifespan, neuronal signalling and transduction, protein trafficking and transmitter production and release. Previous work has shown that 14-3-3 proteins are linked to a variety of pathological neurodegenerative diseases although their role in healthy brain ageing is currently unclear. This study utilised the pond snail, Lymnaea stagnalis to examine the contribution made by 14-3-3 to the decrease in feeding rate that is seen in this model system with age. Interrogation of a Lymnaea CNS cDNA library identified four putative 14-3-3 isoforms, one highly similar to the mammalian 14-3-3ε (14-3-3Lyml), while the other three (14-3- 3 Lym2, 14-3-3Lym3 and 14-3-3Lym3var) were more distinct. Expression, localisation and function of these proteins were studied using a range of biochemical and analytical techniques, in three different animal age groups (3, 6-7 and 10-12 months). Western blot (W8) showed a significant decrease in the overall level of 14-3-3Lym3 in the cerebro-buccal ganglia that correlated with feeding rate. There was no overall change in the expression of 14-3-3Lyml and 2. 14-3-3Lym3var was not detected. CNS 14-3-3 expression was seen in all 11 ganglia including the cerebral and buccal ganglia which are important for regulating feeding. 14-3-3Lyml expression was limited to the neuronal cell cytoplasm and plasma membrane, whereas the remaining isoforms appeared to be distributed throughout the cell, including the nucleus. Expression was shown in key neurones that regulate feeding including identified dopaminergic and serotonergic neurones. 14-3-3 proteins have previously been shown to regulate the synthesis of both dopamine (DA) and serotonin (S-HT) through actions on tyrosine and tryptophan hydroxylase (TH and TPH respectively), the rate-limiting enzymes in their production. HPLC analysis demonstrated that antagonism of 14-3-3 proteins with R18 significantly reduced the production of L-DOPA and S-HTP in the cerebral and buccal ganglia, suggesting that 14-3-3 proteins can regulate DA and S-HT production in these areas. In summary, the 14-3-3Lym proteins are capable of regulating the activity of TH and TPH and the change in expression pattern of these proteins with age may explain the noted age-related changes in S-HT and DA signalling in the cerebro-buccal ganglia and the consequential decrease in feeding rate seen with age.

A wealth of recent evidence implicates increasing obesity levels in the rising global epidemic of type 2 diabetes. At a cellular level, high fatty acid concentrations contribute to increasing p-cell dysfunction and eventual p-cell failure. We have shown that the thiazolidinedione (TZD) rosiglitazone has direct effects on pancreatic p-cell function. The aim of this study was to determine the cell signalling molecules mediating these effects, and to test the hypothesis that rosiglitazone can protect pancreatic p-cells from the detrimental effects of free fatty acids. Utilising the mouse p-cell line MIN6, MTT assays showed that at 5 mM glucose concentrations, addition of 0.4 mM palmitate for 72 hours resulted in a 60% loss of MIN6 cell viability (P<O.O 1). However, the presence of 10 p M rosiglitazone completely abolished the effect of palmitate. To determine the cell signalling pathways involved, MIN6 cells were stimulated with 10 u M rosiglitazone for 2 hours and whole cell extracts analysed. Western blot analysis indicated that total levels of the stress activated p38 MAPK were reduced by over 50% (P<0.05) in the presence of rosiglitazone. Rosiglitazone stimulated phosphorylation of ACC (P<O.Ol), an effect inhibited by compound C, indicating that rosiglitazone activates AMPK in MIN6 cells over 2 hours. Finally, casein kinase 2 (CK2) activity assays indicated that rosiglitazone stimulates a 3-fold increase in CK2 activity (P<O.Ol). This activation was inhibited by compound C, indicating that CK2 lies downstream of AMPK in the signalling pathway stimulated by rosiglitazone. In conclusion, this study has shown that rosiglitazone modulates p38, AMPK and CK2 signalling in MIN6 cells, and can protect MIN6 cells from the detrimental effects of palmitate. Our results indicate that early rosiglitazone administration in obese patients at risk of Type 2 diabetes could well protect and preserve p-cell mass and function.

Regulation of transmembrane ion transport is a vital aspect in the maintenance of a healthy organism. To understand how this highly selective process occurs, how it can become impaired and how impairment may be treated, model compounds are useful tools. Several systems are presently being explored but one of the most widely applicable combines a rigid macrocycle, capable of size-based ion recognition, with membrane spanning substituents that allow the target ions to transverse a phospholipid bilayer. The calixarene class of macrocycles is ideally suited to this task. Previous work had shown that oxacalix[3]arenes could act as models for the filters in natural transmembrane ion channels. Nitrogen-containing analogues of these calixarenes, azacalix[3]arenes, were investigated with a view to constructing a chloride transporting system. Synthetic difficulties encountered when introducing lower rim substitutents precluded the use of azacalix[3]arenes and attention turned to 4-t-butylcalix[n]arenes. 4-t-Butylcalix[4]- and [6]arenes were derivatised with a commercial, membrane disrupting surfactant, Triton X-IOO®, forming compounds designed to form lipid bilayer-spanning, channel-like structures. The ion transporting ability of these, and other bilayer-spanning O-substituted calixarene derivatives, was determined by planar bilayer electrophysiological methods. Results showed that this modular approach to artificial ion channel construction was successful; calixarene derivatives formed transmembrane channels that allowed sodium ions to pass through but not the larger potassium ions.

The unique nature of the needs of children with disabilities and the varied dynamics of family life mean that service provision cannot be boxed neatly into the individual arenas of health, education or social care. These children and their families' present service providers with complex challenges that often test the system. The co-ordination of, and communication between, members of the team around the child often falls to the parent. The concept of 'key working' has been suggested as a way of co-ordinating service provision for children with a disability and their families. However, it has been reported that there are less than one-third of these families who have such a support mechanism in place (Department of Health 2004a). The policy and legislative framework exists for the introduction of the 'key worker' system to health, education and social care practice (Department of Health 2oo4a). Therefore, it is difficult to discern why the key worker role is not more prevalent. However a contributing factor may be that there is no universally recognised definition for the role and no consensus on the specific tasks that should be undertaken by a key worker. Using grounded theory methodology, this qualitative study investigated and explored the dynamics of team working for children with disabilities and the process of co-ordination of services with specific reference to the role of the key worker. Using interviews and focus groups data were generated from professional members of the team, as well as parents of children with disabilities. Analysis of the data identified issues in current practice that present barriers to effective team working and the application of the key worker role. A model of supportive practice was developed to promote improved collaborative team working and utilise the key worker role to provide a more positive experience of service provision for children with disabilities and their families.

The purpose of this research was to explore the interactions between the perceived healthcare needs of people with HIV and the processes involved in their healthcare in order to inform future models of care. A grounded theory approach was adopted utilising semi-structured interviews with 13 HIV patients and 21 healthcare workers in 3 HIV facilities of different size and service specification. Constant comparative analyses of concepts that emerged from the data were undertaken and a dimensional analysis strategy applied to develop conceptual categories and the connections between them. HIV as a condition was conceptualised in different ways by patients and healthcare workers. Although most patients viewed their condition as stable, previous illness experience, uncertainty and the impact of HIV on social integration influenced their views on the role of HIV services. Patient-provider relationships, feeling accepted and participating in care was central to maintaining high levels of patient engagement within the HIV setting. This was in contrast to the felt or enacted stigma experienced by most patients either in other healthcare settings or in their communities and challenges current theory that advances in treatment have reduced the social stigma of HIV. The service user illness representations were not necessarily reflective of HIV service provider views on the health status of medically stable patients or of funding mechanisms for HIV healthcare. A theory of illness representation has been developed utilising the principles of Leventhal’s model adapted for service planning. While HIV clinics were actively adapting services, the pervasive experience of HIV for some stable patients suggests that representations of HIV span a healthy-illness spectrum comprising a complex range of cognitive and emotional processes. These representations influenced how HIV healthcare services were organised and utilised and may be a useful tool to inform healthcare delivery and sustain quality and public health outcomes.

Background: Disorders of movement and posture associated with cerebral palsy (CP) often lead to childhood difficulties with feeding, eating, drinking and swallowing which extend into adulthood. The consequences of compromised eating and drinking skills include respiratory disease, due to food and fluid entering the lungs, and malnutrition, leading to poor growth and health. There is no agreement in clinical and research contexts about the classification of eating and drinking abilities of people with CP to reflect severity of limitations to function. The study aim was to develop a valid and reliable system to classify eating and drinking performance of people with CP, using a pragmatic Mixed Methods approach. Method: The first draft of the Eating and Drinking Ability Classification System (EDACS) was developed from my clinical experience, the research literature and clinical assessments. A series of groups were held, using a Nominal Group Process (NGP), inviting experts to closely examine the content and wording of EDACS. After each group, EDACS was modified and presented to the following group until no new ideas or comments were made. A Delphi Survey (DS) was conducted with a wider group of international experts to further examine and modify the content of EDACS; the DS was repeated until 80% of panellists agreed with the content. In the final stage, EDACS was used by speech and language therapists (SaLTs) and parents to classify the eating and drinking abilities of children with CP; the agreement and reliability between classifications was tested. Findings: Fifty six UK experts participated in 7 nominal groups. The revised EDACS draft was examined by 95 expert panellists in an international DS; more than 80% of panellists agreed with the content of EDACS, after two rounds of the DS. Experts included people with CP, parents, health professionals and researchers. When SaLTs used EDACS to classify 100 children, absolute agreement was 78%, kappa=0.72; ICC=0.93 (95% CI 0.90 to 0.95). Any disagreement was only by one level, with one exception. When SaLTs and parents classified 48 children, absolute agreement was 58%, kappa=0.45, ICC=0.86 (95% CI 0.76 to 0.92). Parents either agreed with SaLTs, or rated their children as more able by one level. The new Eating and Drinking Ability Classification System provides a valid and reliable system for classifying eating and drinking performance of people with CP. EDACS describes the whole range of ability from age 3 years, providing a context for parents to consider their own child’s eating and drinking.

Concerns have been well documented about deteriorating patients being missed and that care has not been of a sufficient standard to maintain their safety. This 'failure to rescue' remains despite changes in training and critical care experts working with ward staff. little is known about what influences decision-making at the point a patient deteriorates and prior to referring on to an expert. The aim of this study was to understand how nurses reach their clinical decisions while caring for a deteriorating patient and to identify the contextual factors that influence that decision-making process. Using grounded theory methodology the study comprised fieldwork, semi-structured interviews and a focus group; participants were 22 nurses and 2 physiotherapists working in general medical and surgical wards. A pragmatist philosophical tradition informing symbolic interaction guided the interpretive analytical framework of the study. The simultaneous collection, memoing, dimensional analysis of the data and constant comparison of the findings with the body of literature, built an emerging theory of clinical reasoning in acute care situations. Findings suggested that acute care nurses practice in one of 3 modes. They are: • 'Ward routine', where normal ward work takes place and nurses use protocols to deliver care. • 'Crescendo of care' where searching, information gathering, checking findings and efforts to gain control over the clinical situation took place. Nurses' reasoning in this mode was abductive and focused on building a believable case prior to referral. • 'Management of crisis' where the nurse was sure of their concerns, made the referral and continues to seek to confirm concerns. Through the three modes nurses reasoned and made sense of the clinical information they picked up. They spent lime marshalling this data until it served them a believable credible case with which to refer to another professional. This involved negotiating and bargaining to elicit action. The goals in these actions and interactions were to keep the patient and themselves safe. This was underpinned and motivated by their personal and professional beliefs. Throughout the whole decision-making process nurses accounted for every decision and judgement they made until they were convinced and confident in what they believed was happening. Then they made a referral to a more senior professional. This was conceptualised as the theory of mind accounting in clinical reasoning 'Which emerged as the explanation for how nurses clinically reason and make decisions when caring for a patient whose condition is declining. The emerging theory offers an alternative explanation of the way nurses assess and intervene when concerned about a patient. This is significant because timely accurate decision-making is fundamental to providing quality care.

Indwelling urethral catheters are the most commonly used medical devices and catheter associated urinary tract infections (CAUTIs) are one of the most common hospital acquired infections. Over 40% of CAUTIs in long-term catheterised patients may be caused by the bacterium Proteus mirabilis. Urease produced by this bacterium generates alkaline conditions by breaking down urea, leading to the formation of dense crystalline biofilm structures on catheter surfaces. This crystalline biofilm makes infections hard to treat and causes the blockage of the catheter lumen, resulting in the retention of infected urine leading to episodes of ascending urinary tract infections. The aim of this study was to identify genes and pathways involved in crystalline biofilm formation by P. mirabilis, in order to inform the development of novel strategies for prevention of catheter blockage. To accomplish this, a bank of random mini-Tn5 transposon mutants was constructed in the clinical isolate P. mirabilis B4. A total of 3840 transposon mutants were screened for phenotypic alterations in biofilm formation. A total of 575 mutants isolated exhibited altered biofilm formation, but comparable rates of growth to P. mirabilis B4 under assay conditions (310 biofilm enhanced; 265 biofilm deficient). The disrupted genes of a subset of 35 transposon mutants were successfully identified. After further phenotypic characterisation 12 transposon mutants were selected and their ability to encrust and block urethral catheters analysed using an in vitro model of the catheterised urinary tract (the bladder model). The bladder models yielded 4 transposon mutants with significant differences in the time taken to block catheters when compared to P. mirabilis B4. Two blocking deficient mutants were further analysed because these types of mutations are most likely to give insights relevant to the prevention of crystalline biofilm formation. Mutants STS8.1D7 and NHBFF9 were disrupted in aspects of the nitrogen metabolism and MFS family transport systems respectively. Timed bladder model experiments and chemical analysis of catheters of these mutants and the wild type B4 were then carried out to further evaluate the differences in crystalline biofilm formation. Overall, transposon mutants that took longer to block catheters displayed a lower level of encrustation after 10 h bladder model experiments. This was confirmed quantitatively by a significant reduction in calcium and biomass deposited onto catheters. Scanning electron microscopy (SEM) and environmental SEM (ESEM) further substantiated the quantitative methods illustrating clear differences in crystalline biofilm distribution for mutants that took longer to block catheters when compared to P. mirabilis B4. ESEM analysis optimized for this purpose allowed the examination of the crystalline biofilm ultrastructure in fine detail in its native, hydrated state and identified delicate calcium based crystal sheets which had not been visualised before. Additional flow chamber experiments confirmed that the ability of the two mutants to adhere to catheter biomaterials was not impaired, highlighting that the initial stages of biofilm formation were not associated with the genes disrupted for these mutants. Overall, the research conducted during this study identified 4 mutants differing in the time taken to block catheters, elucidating 4 genes that are involved in this complex phenotypic trait. Mutants with significant reductions in the ability to block urinary catheters displayed disruptions of the nitrogen metabolism and efflux systems which are believed to be involved in waste management in this bacterium. The inhibition of efflux systems in particular could be of potential value in the treatment or prevention of P. mirabilis crystalline biofilm formation by increasing its susceptibility to antimicrobials, and further investigation of these genes in the future could lead to the development of novel treatments for P. mirabilis CAUTIs.

The primary aim of this thesis was to assess the differences in response to a 3 x 1 minute SLR tensioner treatment between 3 sub-groups of individuals with spinally referred leg pain (somatic referred pain, radicular pain and radlculopathy). · Preliminary studies of the 3 outcome measures were required prior to the main study. These were: validity ofthe method to measure nerve excursion using ultrasound imaging (VI) which was assessed in pig nerves; repeatability of sciatic nerve excursion during a side-lying modified SLR measured with UI in the posterior thigh, and repeatability of pressure pain thresholds (PPT) and vibration thresholds (VT). The 3 outcome measures were repeatable and the sciatic nerve excursion technique was valid. Sixty seven participants were placed into one of the 3 sub-groups and further assessed to identify the presence of central sensitisation (CS). Five questionnaires were completed by participants to assess disability and psychological characteristics. Sciatic nerve excursion, PPT and VT were measured prior to and after a 3 x 1 minute SLR tensioner technique. No significant differences (p>O.05) were found for any of the 3 outcome measures between the 3 groups. Slight improvements in VT were seen in the radiculopathy group after treatment, which were not significant, but indicated that even in individuals with conduction loss, no detrimental changes to nerve conduction occurred after treatment. A varied response to nerve excursion was seen. Longitudinal nerve excursion at the posterior thigh decreased after treatment in individuals with pain below the knee; this location of pain being more common in the radiculopathy and radicular groups. The decrease in nerve excursion suggests regional changes to nerve compliance after treatment, which may have occurred at the nerve root. Since it was n.ot possible to measure nerve root excursion, these findings are speculative. Only 2 participants were identified with CS, suggesting a low prevalence of the condition in individuals with spinaUy referred leg pain. This may be-Clue to individuals with CS choosing not to participate in the study, or a limitation of the method used to identify CS. Disability and psychological factors were not significantly different at baseline between the 3 sub-groups, and were not correlated with the outcome measures. A 3 x 1 minute SLR tensioner technique in individuals with spinally referred leg pain of greater than 3 months of duration is not effective in improving pain or nerve conduction. However, it is not harmful, even in individuals with loss of nerve conduction. Changes to nerve excursion after treatment may be related to individual differences in nerve compliance, and possibly restriction of the nerve root.