Dendritic cells (DCs) are leukocytes specialized in antigen presentation. As competent stimulators of naive T lymphocytes, they link the innate and adaptive immune responses of vertebrates. The RAG-mediated adaptive immune system appeared approximately 500 million years ago in jawed fish and a number of studies suggest that DCs exist in bony and cartilaginous fish. However, the exact role of DCs in the fish immune system is not determined and questions remain as to whether a cell type truly homologous to DCs in homeotherms does exist. My project aimed to identify potential DCs surface markers (CD209A and LAMP3) in rainbow trout (Oncorhynchus mykiss) leukocytes for evaluation of the expression patterns by qRT-PCR under different conditions and stimuli, in vitro and in vivo. Another goal was to validate and evaluate the specificity of a produced anti-trout CD209A polyclonal antibody to further characterise antigen presenting cells (APCs) in fish. The methodology was to look for up-regulation of the predicted markers together with other markers known to be expressed by DCs in mammals and to evaluate at the mRNA and protein expression level after in vitro stimulation of trout primary leukocytes with trout rIL-4/13. Trout CD209A and LAMP3 mRNA was expressed in the main lymphoid organs of fish and could be modulated with microbial mimics. Upon in vitro stimulation of trout primary leukocytes with trout rIL-4/13, trout CD209A mRNA expression was up-regulated together with both CD83 and the MHC class II chain known to be expressed by mammalian DCs. In addition, CD209A protein expression was highly induced by trout rIL-4/13. Taken together, these results suggests that the characterisation of DCs in trout with tools such as transcript evaluation of surface markers and the anti-trout CD209A antibody, could help to more precisely define these leukocyte subsets. These findings could have further impact on fish vaccine improvements and be of importance for the aquaculture industry, by optimising stimulation of adaptive immunity.

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Oxy-Pherol-ET (OP-ET) is an artificial blood substitute composed of perfluoro~ributylamine (FC-43) emulsified with pluronic (FC-68) and hydroxyethyl starch as a plasma expander. This blood substitute is quite unique in that it has a high oxygen and carbon dioxide carrying capacity and is inert. In order for OP-ET to work, it must co-exist in circulation with blood components. This research project has been an investigation of the effect of OP-ET on the circulation regulatory agents (hormonal, etc). The aorta and vena cava were examined to assess the influence of OPET on the structural components of circulation. Since the kidney plays an important role in the overall regulation of circulation, the influence of the OP-ET on its function and structure were examined also. Stimulation of the renin-angiotensin system by hemorrhage, low sodium diet (LSD), and reduced renal perfusion pressure resulted in an increased release of renin in animals treated with OP-ET. Animals previously exchange-transfused with OP-ET were subsequently monitored daily for changes in weight, water intake, and urinary salt and water output. In OP-ET treated animals weight increase was when slow compared to control animals. The water intake of the animals exchange-transfused animals was substantially greater than control animals for the same time period. Animals prepared with indwelling catheters and exchange-transfused with OP-ET were monitored for their ability to respond to pharmacological concentrations of catecholamines and angiotensin II. Under these conditions animals showed no significant difference in blood pressure response when compared to control animals that were exchange-transfused with donor animals' RBCs and treated similarly with angiotensin and catecholamines. Previously transfused animals were monitored to determine the effect of OP-ET on the kidney. Under these conditions there was a diuretic-induced immediate increase in urinary sodium excretion and a gradual increase in urinary potassium. These were expected responses for this diuretic agent. Scanning electron microscopy (SEM) of exchange-transfused animals did not reveal observable differences within the endothelium of the aorta. The vena caval endothelium of the exchange-transfused animals showed no significant changes. There were no observable alterations in the glomerular capillaries by 7 days post-transfusion. The data warrant the conclusion that mechanisms which normally regulate the circulation still function in the presence of the blood substitutes used in this study. The use of OP-ET has great potential in emergency medicine and remote areas of the world where whole blood would be difficult to maintain.

Evidence from multiple studies suggests that regulation of emotions and intensity of affect may be relevant to understanding disordered eating. Emotion regulation concerns the ways in which emotions are managed in daily life, whereas Affect Intensity (Larsen et al., 1986) refers to individuals‟ typical emotional reactivity. The thesis examines emotion regulation and affect in females with eating pathology (subclinical as well as clinical), and looks at ways dysfunctional regulatory strategies may be improved. The main objective of the present research was to look at the influence of experimentally-induced positive affect on the choice of emotion management strategies. Study 1 looked at typical Affect Intensity and emotion regulation in a sample of subclinically eating-disordered University of Edinburgh students. This study examined functionality of regulatory strategies, typical intensity of affect, and the effects of experimentally induced happiness and sadness on the two. Study 2 introduced the construct of creativity into the discourse on emotions and psychopathology, and looked at creative tendencies in relation to Affect Intensity, emotion regulation and psychopathology (anxiety, depression and sub-clinical eating pathology). Study 3 looked at the effects of Positive Psychology Interventions (PPIs) on emotion regulation, life satisfaction, anxiety and depression in a subclinically eating-disordered group and controls. Studies 4 and 5 were carried out in order to test and extend the results of Studies 1 and 3 with a clinical sample. In Study 4, emotion regulation, Affect Intensity and the immediate post-test effect of happiness on emotion regulation and life satisfaction were examined in females clinically diagnosed with eating disorders (i.e. anorexia nervosa, bulimia nervosa, and EDNOS). Study 5 looked at how longitudinal happiness induction influenced emotion regulation, eating behaviours and life satisfaction in eating-disordered individuals. One of the main findings across the studies was that females with subclinical and clinical forms of eating pathology tended to experience negative emotions of high intensity, and used predominantly dysfunctional regulatory strategies to manage them. Another important finding was that experimentally-induced positive emotions improved emotion regulation, and encouraged participants to choose healthier affect management strategies. The studies, their implications and contribution to theory and treatment of eating disorders are discussed.

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The dissertation consists of two essays on insurance markets and regulation. The first essay studies the timing of state-level tort reform enactments between 1971 and 2005. Using discrete time hazard models, we find the level of litigation activity---as measured by incurred liability insurance losses, the number of lawyers, and tort cases commenced---to be the most important and robust determinant of tort reform adoption. Political-institutional factors and regional effects---such as Republican control of the state government, single party control of the legislature and governorship, and a (relatively) conservative political ideology among a state’s Democrats---are also associated with quicker reform adoption. In the second essay, we identify the effect of public guarantees on market discipline by exploiting the rich variation in U.S. state guarantees of property-liability insurer obligations. We find government guarantees significantly reduce the sensitivity of premium growth to changes in financial strength ratings, and that this reduced sensitivity applies to both price and volume changes. The effects are concentrated among insurers rated A- or lower by A.M. Best, the leading financial strength rating agency in the insurance industry. For downgraded insurers, we find that premium growth in business not covered by state guarantees falls in relation to growth in its covered business, with the estimate of the difference being as high as 15% for A- rated insurers and 10% for insurers rated below A-.

Students who are self-regulated are more likely to succeed academically, whereas students who have deficiencies in their learning have been recognized as having a lack of metacognitive awareness (Valdez, 2013; Zimmerman, 2002). If students are metacognitively unaware in large introductory courses, they may have difficulty knowing when to self-regulate and modify their learning (Lin & Zabrucky, 1998; Stone, 2000). One manner in which researchers have assessed students’ metacognitive awareness is by asking students to estimate how they think they will do on tasks compared to their actual performance, known as calibration. The purpose of this study was to examine students’ calibration and study habits. Participants were undergraduates (N = 384) in an introductory biology course at a southeastern U.S. university. Students completed four surveys that assessed their exam score expectations and the study habits they used prior to each exam. Results showed that students’ estimates are most discrepant from their actual performance early in the semester and become more accurate at the end of the semester. A closer look at students’ study habits revealed that the inaccuracy of students’ exam judgments showed little connection to the study strategies that students used. Findings from this study are important for biology instructors.

Thesis (MSc)--University of Stellenbosch, 2000. / ENGLISH ABSTRACT: The fission yeast Schizosaccharomyces pombe is able to effectively degrade extracellular L-malate by means of a permease for the active transport of L-malate and a malic enzyme that catalyses the intracellular oxidative decarboxylation of L-malate to pyruvate and CO2. Sequence analysis of the S. pombe NAD-dependent malic enzyme gene, mae2, revealed an open reading frame of 1695 nucleotides, encoding a polypeptide of 565 amino acids. Mutational analyses of the mae2 promoter region revealed several putative cis-acting elements. Two of these elements have homology with binding sites for eukaryotic cAMPdependent regulatory proteins. The UAS I showed homology with the invert of the ADRI binding site, an AP-2 binding site and the TGGCA element. The other putative cAMPdependent site, UAS2, showed homology with the binding site for ATF/CREB and proved to be a strong activator sequence that is required for expression of the mae2 gene. Three negative acting elements, DRS I, DRS2 and DRS3 seem to function co-operatively to repress transcription of the mae2 gene. In this study northern and western blot analyses, as well as malic enzyme assays, showed increased levels of mae2 transcription and enzyme activity when cells were grown under fermentative conditions. The levels of mae2 expression increased approximately 4-fold in 30% glucose and 3-fold under anaerobic conditions. These increased levels of malic enzyme may provide additional pyruvate for various metabolic processes when the mitochondria are not fully functional under fermentative conditions. The regulated expression of the mae2 gene was further investigated using mae2-1acZ fusion plasmids that carried mutations in the DASI, UAS2 or the triple mutated DRSI/URS2/URS3 elements. These plasmids were transformed into S. pombe strains with mutations in the cAMP-dependent or stress-activated signal transduction pathways to determine the signal for the increased expression of the mae2 gene. The cAMP-dependent (Pkal ) and general stress activated (Styl) pathways often act in parallel to regulate the activation of transcription factors necessary for the expression of several S. pombe genes under different physiological conditions. The results presented here suggest that regulatory proteins involved in the Pka l and Styl pathways play a role in the regulation of the mae2 gene under fermentative conditions. Furthermore, some of the regulatory cis-acting elements in the mae2 promoter may interact with these trans-acting factors to regulate the transcription of the gene under different growth conditions. The mechanism of this interaction is not yet known and further research is required to identify all the transcription factors involved in the regulation of the mae2 gene. / AFRIKAANSE OPSOMMING: Die splitsingsgis S. pombe is in staat om ekstrasellulêre L-malaat effektief af te breek danksy 'n permease vir die aktiewe opname van L-malaat en 'n malaatensiem wat die intrasellulêre oksidatiewe dekarboksilering van L-malaat na pirovaat en C02 kataliseer. DNA-geen opeenvolgings van die NAD-afhanklike malaatensiemgeen, mae2, het 'n oopleesraam van 1695 nukleotiede getoon wat vir 'n polipeptied van 565 aminosure kodeer. Mutasie-analise van die mae2-promoter gebied het verskeie moontlike cis-werkende elemente getoon. Twee van die elemente toon homologie met bindingsetels vir eukariotiese cAMP-afhanklike regulatoriese proteïene. Die DAS 1 toon homologie met die omgekeerde volgorde van die ADRI bindingsetel, 'n AP-2 bindingsetel en 'n TGGCA element. Die ander moonlike cAMP afhanklike setel, DAS2, toon homologie met die bindingsetel vir ATF/CREB en is 'n sterk aktiveringselement wat vir die uitdrukking van die mae2-geen benodig word. Drie onderdrukker-tipe elemente, DRSI, DRS2 en DRS3, funksioneer moontlik gesamentlik om die transkripsie van die mae2-geen te onderdruk. In hierdie studie het northern en western klad analise, sowel as malaatensiem aktiwiteitstoetse verhoogde vlakke van mae2-transkripsie en ensiemaktiwiteit getoon wanneer die kulture onder fermentatiewe toestande gegroei het. Die uitdrukking van die mae2-geen het ongeveer 4-voudig toegeneem in 30% glukose en 3-voudig onder anaërobiese toestande. Hierdie verhoogde uitdrukking van die malaatensiem mag addisionele pirovaat vir verskeie metaboliese behoeftes voorsien wanneer die mitochondria onder fermentatiewe toestande nie volkome funksioneer nie. Die uitdrukking van die mae2-geen is verder onder fermentatiewe toestande bestudeer deur gebruik te maak van mae2-lacZ-fusie plasmiede wat mutasies in die moontlike DASI, DAS2, of die drievoudig-gemuteerde DRS I/URS2/URS3 setels bevat. Hierdie plasmiede is in S. pombe rasse met mutasies in die cAMP-afhanklike of stres-geaktiveerde seintransduksie paaie getransformeer om die sein vir die verhoogde mae2-geen uitdrukking te bepaal. Die cAMP-afhanklike (Pkal) en algemene stres-aktiverings (Styl) pad werk soms in parallel om die aktivering van transkripsiefaktore betrokke in die uitdrukking van verskeie S. pombe gene onder verskillende fisiologiese toestande to bewerkstellig. Ons resultate dui daarop dat die regulatoriese proteïene van die Pkal en die Styl paaie 'n rol in die regulering van die mae2- geen onder fermentatiewe toestande speel. Daar is ook aanduidings dat sommige van die regulatoriese cis-werkende elemente in die mae2-promoter wisselwerking met die transwerkende faktore toon om die transkripsie van die geen onder verskillende groeitoestande te reguleer. Die meganisme van hierdie interaksie is nog nie bekend nie en verdere navorsing is nodig om al die transkripsiefaktore wat by die regulering van die mae2-geen betrokke is, te identifiseer.

Infants and toddlers who experience physical abuse and/or neglect are at a severe risk for disruptions to emotion regulation. Recent prevention and treatment efforts have highlighted center-based child care as an important setting for providing support to the needs of these children, as child care centers are already an existing point of entry for reaching high-risk families. Guided by ecological theory, this review draws on the maltreatment and child care literatures to consider the opportunity for child care centers, specifically teacher-child interactions within the classroom, to support the unique regulatory needs of maltreated infants and toddlers. Existing research on the effects of child care for children facing other types of risk, as well as research with maltreated preschool children, provides a foundation for considering the role child care may play for infants and toddlers, whose emotion regulation skills are just emerging. More research is needed regarding teachers' roles in facilitating effective emotional experiences in the classroom that meet the unique needs of maltreated children. Additionally, early childhood teacher training that focuses on infant/toddler mental health and a trauma-informed perspective of care, as well as structuring child care centers as communities of support for high risk families, all may aid child care centers in better serving this vulnerable population. (C) 2016 Elsevier Ltd. All rights reserved.