Cationic lipids are efficient tools to introduce nucleic acids and proteins into cells. Elucidation of the mechanism and cellular pathways associated to such a transport has been relatively slow, even though significant progress has been made in the characterization of the intracellular trafficking of cationic lipid/DNA complexes. Surprisingly, little is known about the effects of these delivery vectors on cell functioning. In the present thesis, we show that cationic lipids and cationic lipid/DNA complexes strongly increase the intracellular Ca2+ concentration. The end point of the Ca2+ increase was ~400 nM from a basal level of ~100 nM. The [Ca2+]i increase was studied using K562 and Jurkat cells cultured in vitro. This effect is weakened following addition of DNA to cationic liposomes, although remaining very large at cationic lipid/DNA ratios commonly used for cell transfection experiments. Removal of extracellular Ca2+ did not abolish this effect significantly and preincubating K562 cells with the Ca2+-ATPase inhibitor thapsigargin strongly abolished intracellular Ca2+ concentration increase, indicating that Ca2+ was released mainly from internal Ca2+ stores sensitive to thapsigargin. Pretreatment of the cells with the phospholipase C inhibitor U73122 blocked the intracellular Ca2+ concentration rise, suggesting an inositol pathway-dependent mechanism. LDH release assay indicates that in the conditions used for fluorescence measurement and in those used to transfer DNA into cells, cationic liposomes diC14-amidine and DOTAP had no massive cytotoxic effects. Cationic liposomes showed more toxicity than their corresponding complexes; this toxicity decreases in the presence of serum. The effect of cationic lipids on phosphatidylinositol-specific phospholipase C (PI-PLC) was quantitatively assessed using phosphatidylinositol (PI) and radiolabeled phosphatidylinositol ([3H]-PI). Incorporation of diC14-amidine into PC/PI vesicle activated PI-PLC and was shown to activate the hydrolysis of PI and [3H]-PI. Our data may suggest that mobilization of intracellular Ca2+ by complex could have an effect on the transfection process itself. These results indicate for the first time that cationic lipids and cationic lipid/DNA complexes are not inert and can affect the functioning of the cells by increasing their intracellular Ca2+.

The Rodeo-Chediski Wildfire the largest in Arizona's history at the time of burning damaged and disrupted ecosystems resources and functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus Ponderosa) forests exposed to the burn. Impacts of this wildfire on ecosystems resources and functioning were studied from shortly after the cessation of the wildfire in late summer of 2002 through the spring of 2007 on two previously instrumented watersheds located on sandstone derived soils within the burn. One watershed was burned by a high severity (stand-replacing fire), while the other watershed burned in a low severity (stand-modifying) fire. This dissertation focuses on the effects fire severity had on watersheds resources and functioning in terms of the tree overstories, herbaceous understories, large and small mammals, avifauna, hydrologic functioning, soil water repellency, hillslope soil movement, and fuel loadings. The results of these studies indicated the cumulative impacts incurred to ecosystem resources, hydrologic functioning, and flammable fuels were much greater on the watershed exposed to the high severity (stand-replacing) fire. It is anticipated that the overall ecological and hydrologic function on the watershed burned by a high severity will not approach pre-fire conditions for many years. The watershed burned at a low severity, however, was approaching pre-fire conditions nearly five years after fire and is expected to be recovered within the next few years.

The lived experiences of the family of a Traumatic Brain Injury (TBI) survivor is an under represented, yet growing field of qualitative psychological research. This thesis used a case study approach with a family in which one member sustained TBI thirteen years previously. Using conversational unstructured interview techniques, I participated with the family in eliciting public narratives around their experiences since the accident. These public stories were also thickened by individual interviews, which both supported and contradicted the public narratives. In the analysis I found two major narrative lines, the first of which was the baby-narrative which held that the injured person must not be injured any further in word or deed and must be protected at all time. The second dominant narrative was the fighting-narrative, which was characterised by language and actions around fighting/battling on behalf of the injured person against uncaring ‘others’. Several important suppressed or counter narratives emerged during the individual interviews, which could not be spoken about publically. I conclude that the power of the two dominant narratives is fuelled by constant rehearsal and enactment, which actually freezes the family and does not allow it to move forward. Suppressed stories are discussed as a possible avenue for therapeutic growth and for the evolution of the family story as they age.

Maladaptive interpersonal functioning is considered typical of eating disorders. The present thesis aimed to add to existing knowledge of interpersonal functioning in the eating disorders in terms of both symptomatology and treatment. In Study 1, relationships were found between eating disorder attitudes and several types of poor interpersonal functioning. These associations were present when controlling for depression and anxiety. Study 2 found that generalised interpersonal problems were more likely to be reported by women with bulimic disorders than comparison women, apart from problems with being too open, which were more likely to be reported by comparison women. In Study 3, individuals with self identified eating disorders were found to have poorer problem solving skills in specific interpersonal situations than healthy controls, generating less means to solve the problem, with these means being significantly less effective and less specific than those generated by healthy controls. In Study 4, the experience of an invalidating childhood environment was explored as a potential predictor of adult interpersonal problems in the eating disorders. Viewing the expression of emotions as a sign of weakness was a mediator of the relationship between having a more invalidating mother and adult eating concern in a nonclinical population. In Study 5, the interpersonal experiences of patients with bulimic disorders are explored using qualitative methodology. They report a range of problems characterised by social avoidance, social anxiety, non-assertiveness, and a difficulty with being genuine in relationships. In Study 6, patients reported their experiences of interpersonal psychotherapy for bulimic disorders. In general, they experienced the therapy as positive and beneficial. They express that it helped them address a range of interpersonal problems, and reduced but did not cure their eating disordered behaviours. Patients liked that therapy focused on both interpersonal relationships and eating. In Study 7, interpersonal psychotherapists discussed their perceptions of the modified therapy. They identified several factors as being related to outcome, such as the existence or willingness to build a support network, motivation to change, a clear interpersonal problem identified in the patient, level of depression, duration of the eating disorder and keeping therapy focused on the interpersonal. Results of these studies suggest that those with higher levels of eating disorder related attitudes and behaviours often have significant problems with interpersonal functioning. This thesis supports the use of interpersonal psychotherapy as a viable treatment approach to the eating disorders. It also supports the use of the modified version of the therapy, which addresses eating as well as interpersonal functioning.

The affective disorders (anxiety and depression) are common psychiatric disorders that primarily involve disturbances in mood and represent the second leading source of disease burden world-wide. A wide base of evidence supports a significant genetic contribution to these disorders. Polymorphic variation in the promoter region (5-HTTLPR) of the human serotonin transporter (hSERT) gene, which leads to a life-long alteration in serotonin transporter (SERT) expression and functioning, has been implicated in the aetiology of both anxiety and depression. Despite the strong evidence implicating a role for this polymorphism in affective psychopathology the underlying mechanism by which genetically determined SERT bioavailability influences affective functioning are not understood. In these studies I attempt to elucidate the alterations in cerebral, serotonin (5-HT) system and hypothalamo-pituitary-adrenal (HPA) axis functioning which may relate to the effect of the 5-HTTLPR on affective functioning by characterising these parameters in an animal model of genetically increased SERT expression (hSERT over-expressing mice; hSERT OVR). Furthermore, as gender influences both the likelihood of developing affective disorders and the impact of the 5-HTTLPR on affective functioning, with a greater effect being observed in females than in males, we characterise these parameters in mice of both genders. The data presented in this thesis demonstrate that the life-long increase in SERT bioavailability present in hSERT OVR mice produces profound alterations in cerebral, serotonin system and HPA axis functioning. Furthermore, the influence of increased SERT expression upon cerebral and serotonin system functioning is greater in females than in males. Additionally, a number of sexually dimorphic variations in serotonin system functioning were identified. Thus this thesis extends the currently available information regarding the underlying mechanisms by which gender and a life-long alteration in SERT expression may influence the risk of affective psychopathology.

G protein-coupled receptors (GPCRs) form a link between the cell and their environment when signaling pathways are activated upon ligand binding. However, the ligands and functions for many GPCRs remain to be determined. G protein-coupled receptor 50 (GPR50) is one such orphan, and its exact role is yet unknown. There is however emerging functional and genetic evidence suggesting a function for GPR50 in psychiatric illness and lipid metabolism. It was hypothesised that investigating GPR50’s protein-protein interactions would lead to a greater understanding of the role of GPR50 in normal brain functioning and in mental illness. Putative protein interactors were initially isolated by a yeast two-hybid study and were further tested here. To address GPR50’s links to mental illness, the GPR50∆502-505 deletion variant associated with mood disorders was also investigated. To test this hypothesis I sought to confirm some of the key yeast two-hybrid interactions. Using co-immunoprecipitation and immunocytochemistry the interaction of GPR50 with reticulon family members Nogo-A, Nogo-C and RTN3, and with cell-cell adhesion molecule CDH8 and lipid-associated protein ABCA2 were validated. In order to identify the location of interactions, subcellular fractionation of mouse brain and rt-PCR and immunohistochemistry in developing and adult mouse brain were performed. GPR50 and several interactors were found to be enriched at the synapse by subcellular fractionation of whole adult brain, and at embryonic day 18 (E18) and 5 weeks by rt-PCR. Colocalisation of GPR50 and interactors was found in the amygdala, hypothalamus, cortex and specific brain stem nuclei by immunohistochemistry. The discovery of GPR50 expression in noradrenergic, serotonergic and dopaminergic nuclei in the adult brain stem suggests a further role for GPR50 in neurotransmitter signaling and stress. To investigate the function of GPR50 two assays were performed that measure processes which are known to be affected by Nogo and RTN3: The first assay was a neurite outgrowth assay in Neuroscreen-1 cells, a PC12 cell clone. A significant increase in neurite length was detected after transient overexpression of GPR50 and this effect was increased in the GPR50∆502-505/T532A variant. Additionally GPR50-overexpression resulted in an increase in filopodia formation suggesting a role in actin dynamics. As a second functional assay in vitro BACE1 activity assays were performed in HEK293 cells. GPR50 but not GPR50∆502-505/T532A overexpression resulted in a significant increase in BACE1 activity. Lastly a final series of pilot experiments were performed to gain insight into the secondary structure of the C-terminal domain and the effects of the polymorphisms on structure. The 35kDa GPR50 C-terminal domain was purified and Circular Dichroism studies indicated a predominantly unstructured protein with increased a- helical content in the GPR50∆502-505 variant. The results in this thesis indicate a role for GPR50 in neuronal development and synaptic functioning. The results also strengthen an association with major mental illness, with links to several disease mechanisms.

Based on existing theories of personality and socio-emotional functioning (e.g. Clark, 2005; Lynch, Hempel & Clark, in press) a new model is proposed and tested. The model hypothesises that (i) temperament (reward and threat sensitivity) and childhood invalidation predict problems with interpersonal functioning, (ii) this effect is mediated by self-regulatory capacity; where self-regulatory capacity comprises self-control (ranging from emotional over-control to emotional under-control) and flexible control and (iii) self-regulatory capacity itself has a quadratic relationship with interpersonal functioning. A UK community sample (n= 512) completed a self-report survey, measuring each of the aforementioned latent variables. Structural equation modelling (SEM) was used to determine the goodness-of-fit of this and variations of this model. SEM identified that a non-mediation model provided the best fit (χ²=49.403, p< 0.001; CFI=0.98; RMSEA=0.056). Good-fit was obtained for a model including flexible control as a partial mediator (χ²=269.06, p< 0.001; CFI=0.956; RMSEA=0.081) and adequate-fit for a model including over-control as a partial mediator (χ²= 91.744, p < 0.001, CFI=0.932; RMSEA= 0.096). Correlation analyses suggested that over-control and under-control correlated positively with interpersonal problems. Results from SEM provided promising initial evidence for the mediating role of self-regulatory capacity, particularly for the flexible control component. Correlation analyses provided support for the non-linear relationship between self-regulatory capacity and interpersonal functioning, whereby extreme over-control or extreme under-control is associated with interpersonal problems. Findings have implications for identifying mechanisms of change for therapeutic approaches to emotion dysregulation and for understanding the over-controlled population, which has previously been overlooked.

The thesis aim was to increase understanding of interpersonal antecedents and consequences of rumination, defined as ‘repetitive and passive thinking about one’s symptoms of depression and the possible causes and consequences of those symptoms’ (Nolen-Hoeksema, 2004, p.107). As a proof-of-principle study, rumination predicted diminished relationship satisfaction, three months later, in a sample of remitted depressed adults (N = 57). In the next study, rumination was associated with a maladaptive submissive interpersonal style and rejection sensitivity, controlling for depressive symptoms, other interpersonal styles and gender, in a different sample (N = 103 currently depressed, previously depressed and never depressed adults). Subsequent chapters incorporated a second assessment point of data from this same sample. Longitudinal analyses were undertaken to investigate; a) do rumination and depressogenic interpersonal factors predict future depression?; b) does rumination prospectively predict increased rejection sensitivity and submissive interpersonal behaviours, and, vice-versa, do these interpersonal factors predict increased rumination?; c) does rumination prospectively predict poor social adjustment and interpersonal stress? Consistent with previous findings, Time 1 rumination predicted increased depression six months later. Unexpectedly, the effect of rumination on future depression was mediated by its relationship with the submissive interpersonal style. Partially consistent with the stated predictions, Time 1 rejection sensitivity (but not the submissive interpersonal style) prospectively predicted increased rumination, but rumination did not predict rejection sensitivity or the submissive interpersonal style. As predicted, rumination prospectively predicted increased chronic interpersonal stress and poor social adjustment (but not acute interpersonal stress). In a final study, rumination was manipulated via an applied intervention (concreteness training, CT), within the context of a randomized controlled trial (N = 79 clinically depressed adults). Analyses compared the change in social adjustment and submissive interpersonal behaviour reported in the CT condition compared to a treatment as usual (TAU) condition. There was a significantly greater reduction in rumination in the CT compared to TAU condition, p < .05. Moreover, the reduction in submissive interpersonal behaviours was significantly greater in the CT compared to TAU condition, p < .05. The change in social adjustment was not greater in the CT compared to TAU condition. Thus, a psychological intervention which reduces rumination decreased maladaptive submissive interpersonal behaviour. The implications of the findings are discussed in relation to theory of rumination and interpersonal theories of depression.

The study analyzed how parenting stress and discouragement affect stepfamily functioning. Whether the parent was a biological parent or stepparent, whether the stepparent was a stepmother or stepfather, or whether the marriage had been formed more or less than two years was also considered. One assumption made was that increased parenting stress and discouragement will lead to decreased family functioning. Other assumptions were that there will be more increased parenting stress and discouragement and decreased family functioning found in stepparents than biological parents, in stepmothers more than stepfathers, and in parents in families formed less than two years more than those in families formed more than two years. Complete data was collected from 30 subjects. Three instruments were used in the study. The Parenting Stress Index measures how much stress parents experience in areas relating to how they see their child and how they see themselves as parents. The Discouragement Scale for Adults was developed to measure the Adlerian concept of discouragement in an adult population. The Family Assessment Device measures how a family functions.

Although research is unequivocal concerning the important role of parenting in the prediction of a range of youth psychosocial outcomes, few empirical studies have examined potential contributions of parental individual differences factors to variability in parenting behaviors. Among the few studies that have, individual differences in affective dimensions of temperament (i.e., Negative Temperament [NT] and Positive Temperament [PT]) and executive functioning (EF) have individually emerged as potential key processes underlying parenting behaviors; however, they have yet to be examined jointly. Thus, using a latent variable approach, within a racially and ethnically diverse community sample of 166 parents, the current study examined the joint and interactive contribution of temperament and EF in the explanation of parenting. Further, despite conceptual overlap, parenting research has historically employed two distinct conceptual approaches: parenting practices and styles. The current study thus fitted a single integrative three-factor model (i.e., positive parenting, negative parenting, and corporal punishment) of parenting behaviors that included both styles and practices. Results suggested that parenting behaviors can be conceptualized within a single, three-factor model, allowing for the incorporation of historically distinct conceptions of parenting. Further, results revealed that affective dimensions of temperament and EF were uniquely but differentially associated with all parenting domains and EF moderated the associations between both NT and PT and positive parenting. All told, the current study provides support for an integrative model of parenting behaviors and parental temperament and EF, and their interaction, as potential critical processes associated with individual variability across parenting behaviors.