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The HIV-1 Gag p24 protein contains the HLA class-1 B*2705 restricted epitope KK10, responses to which are associated with delayed progression. Data from in vitro proteasomal digestion studies from our group has shown the production of a number of C-terminally extended and truncated epitopes containing KK10, produced in far higher quantities during proteasomal digestion than this “optimal epitope” and that the amount of antigen made in proteasomal digestion is instrumental in determining the development of immunodominance. This work aims to characterise the contribution of these naturally processed epitope forms to the cellular immune response to this region. Further proteasomal digestion studies have shown that the common KK10 intra-epitope escape mutant sequences R132K and L136M have major effects on epitope production by the proteasome and that a range of short peptides containing the N-terminal of the KK10 sequence are produced in large quantities by the proteasome. Recognition of the KK10 epitope forms by HLA B*2705 HIV-1 patients were characterised ex vivo and show recognition of KK10 epitope forms somewhat independent of the presence of KK10 recognition, we also show cross-recognition between KK10 epitope forms by CD8+ T cells, as well as recognition by CD4+ T-cells. TCR from CD8+ T-cells specific for KK10 epitope forms were found to share common features in the HLA binding CDR hyper-variable loops. Structural studies of the HLA B*2705 molecules in complex with the KK10 epitope forms show a shared binding motif at the N-terminus, and to a lesser extent, the C-terminus of the binding groove which may facilitate cross-recognition of complexes. In addition these studies show a potentially novel binding mode for a 14mer peptide, and refolding of truncated KK10 peptides as short as a 4mer with the HLA B*2705 molecule (crystallisation with a 6mer peptide shown). This demonstrates previously unrecognised flexibility of the HLA class-1 to bind and present peptides of different lengths to T-cells. We show that these HLA B*2705 binding-capable truncated peptides do not induce a CD8+ T-cell response in HLA B*2705 HIV-1 patients and may be able to block CD8+ T-cell responses to the KK10 epitope. This might represent a novel form of viral CTL escape. In addition we observe the presence of KK10 flanking mutations in patient sequences and significant associations between the presence of intra-epitope escape mutations, KK10 recognition and patterns of escape in flanking sequences. Finally we note the reduction in binding of KIR3DL1 to KK10 epitope forms relative to the KK10 epitope-HLA B*2705 complex. The presence of HLA B*2705 and KIR3DL1 associate with improved disease course in HIV-1 though the mechanism through which this occurs has yet to be defined.

Thesis advisor: Bernard O'Brien / This study investigated factors which influenced stable, primary love relationships among twelve lesbian couples who had been together at least fifteen years and had not reared children together. Each participant was interviewed separately in a retrospective, semi-structured interview that assessed the impact of selected factors over the course of the relationship. Each factor was examined to determine its influence in the beginning phase of the relationship (the first 5 years), in the middle phase (5-10 years into the relationship), and most recently (beyond 10 years into the relationship). Interpersonal dynamics as well as the influences of culture, religion, values, finances, and social supports were explored to determine their impact on relationship stability. / Thesis (PhD) — Boston College, 1994. / Submitted to: Boston College. School of Education. / Discipline: Counseling, Developmental Psychology, and Research Methods.

Faculty of Orthodontics School of Health Sciences 81/0315/8 Miltstein@global.co.za / The incidence of relapse following orthodontic treatment has always been of paramount interest to clinicians and research workers. Many investigations have been carried out at various Universities to assess the long-term stability of orthodontic treatment. This study assessed the stability of 31 cases at least ten years out of retention treated by post-graduate students in the Department of Orthodontics at the University of the Witwatersrand, Johannesburg. Associations between certain clinical parameters and postretention relapse were also evaluated. Occlusal changes which had taken place were assessed by evaluating data from models taken prior to treatment and comparing these with similar parameters at the end of treatment and, on average, just less than 13 years following the end of retention. Eleven parameters were recorded and measured according to a scoring system proposed by Sadowsky and Sakols. A total malocclusion score was obtained for each study model by calculating the algebraic sum of all the scores. The total malocclusion scores thus indicated the severity of malocclusion presented by each study model at each period. A further examination of each of the study models was carried out in order to establish the Irregularity Index. The anatomic points at which contact would be made were defined on each surface of the six mandibular anterior teeth. The distance between the contact points of the adjacent teeth were measured using a digital vernier caliper calibrated to the nearest 0,05mm. The sum of these 5 measurements provided the Irregularity Index. Values for mandibular irregularity were then grouped into minimal, moderate and severe categories. v Changes in the intercanine and intermolar widths were correlated with overbite, overjet and anterior mandibular crowding parameters. The study also determined whether the presence or absence of third molar teeth and/or premolar extraction therapy were associated with relapse. At postretention 54.8 percent of the sample displayed some degree of relapse in at least one of the variables studied. However, all of the variables studied showed a greater degree of stability than relapse. Canine relationship showed the most postretention stability, whilst deep bite, overjet and molar relationships showed the least. With a few exceptions, occlusal abnormalities which were considered to be severe at the commencement of treatment demonstrated a high degree of stability following corrective therapy, whereas the relapse of mild to moderate features prior to treatment was not as predictable. The small amount of change noted in intercanine and intermolar widths at all three stages of treatment were not significant predictors of relapse at the 5 percent significance level of the parameters assessed. Furthermore the presence or absence of third molar teeth was not a significant predictor of poor postretention malocclusion score, overjet or overbite. Similarly extraction therapy was not a significant predictor of lower incisor alignment relapse (p=1.0). The mean irregularity index of the whole sample following retention indicated that the lower incisors displayed minimal crowding (2.7 mm). Following at least ten years out of retention, treated cases in the Department of Orthodontics, University of the Witwatersrand, Johannesburg showed a high degree of stability for the parameters assessed.

Programmers design, write, and understand programs with a high-level structure in mind. Existing programming languages are not very good at capturing this structure because they must include low-level implementation details. To address this problem we introduce Twig, a programming language that allows for domain-specific logic to be encoded alongside low-level functionality. Twig's language is based on a simple, formal calculus that is amenable to both human and machine reasoning. Users may introduce rules that rewrite expressions, allowing for user-defined optimizations. Twig can also incorporate procedures written in a variety of low-level languages. Our implementation supports C and Python, but our abstract model can accommodate other languages as well. We present Twig's design and formal semantics and discuss our implementation. We demonstrate Twig's use in two different domains, multi-language programming and GPU programming, and compare Twig against a well-known typemapping system, SWIG.

BACKGROUND: Pre-term delivery is known to cause developmental problems due to the fragile nature of the premature brain. In particular, ventriculomegaly is a commonly observed phenomenon due to the hemorrhaging of the germinal matrix, and may cause alterations in the volumes of gray matter, white matter and cerebrospinal fluid in growing pre-term children. METHODS: The volume and symmetry of a sample population of ELGAN (Extremely Low Gestational Age Newborns) and normal-term population obtained from the NIH Study of Normal Brain Development was evaluated. The ELGAN group consisted of 88 subjects from age group 9 to 11 and the normal-term group consisted of 68 subjects from age group 7 to 11. Magnetic resonance images were taken from both samples and the intracranial matter was measured and segmented. RESULTS: Histograms of the obtained volumes showed a normal distribution and statistical analysis for each sample group and gender. The ELGAN group had higher intracranial volumes and showed statistically significant asymmetry that was not present in the normal term population with a larger right brain than left brain. Discussion: Results indicate that preterm delivery may alter processes that allow for symmetrical brain development and heavily favor the relative higher expansion of the right side of the brain. CONCLUSION: Further analysis of the concentration and location of the white matter and gray matter in both preterm and normal term children is necessary in order to understand the adaptive mechanisms that may be activated in order to offset the damage done to the premature brain.

Li, Shiqi. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 21-22). / Abstracts in English and Chinese. / Abstract --- p.i / Abstract in Chinese --- p.ii / Acknowledgements --- p.iii / Tables of Contents --- p.iv / List of Figures --- p.v / Chapter Chapter 1: --- Introduction --- p.1 / The Nature of Shape: Spatial or Featural --- p.1 / Object Short-Term Memory vs. Spatial Short-Term Memory --- p.4 / The Present Study --- p.5 / Chapter Chapter 2: --- General Method --- p.9 / Participants --- p.9 / Stimuli --- p.9 / Procedure --- p.10 / Chapter Chapter 3: --- Experiment 1 Colors vs. Dot Patterns --- p.14 / Results and Discussion --- p.14 / Chapter Chapter 4: --- Experiments 2 & 3 Ellipses vs. Dot Patterns/Colors --- p.16 / Results and Discussion --- p.16 / Chapter Chapter 5: --- General Discussion --- p.18 / "Treatment of ""Shape"" in Previous Studies" --- p.18 / Structural Description in Object Recognition --- p.19 / References --- p.21

In Experiment one 7 Brushtail possums were trained, using food, to perform a Delayed-Matching-To-Sample procedure using still and flickering light stimuli, over a 0, 1 and 2 second delay. A criterion of 80 percent correct for 5 consecutive days was set for the requirement to probe test. Probe session delays were 0, 0.5, 1, 2, 4, and 8 seconds. Performance was analysed using the measure of discrimination log d. Log d = 1 at the possums training delay and dropped back to log d = 0 at the longer inexperienced delays. The possums performance at this task was only adequate, so in case the stimuli were causing discrimination difficulties they were changed for the following experiment to horizontal and vertical light stimuli. Experiment two used the horizontal and vertical light stimuli to further test DMTS in possums. The possum's responding stayed at 50 percent correct, or chance, so the task was changed to a Simultaneous-Choice procedure. However, this did not have any effect on improving their results with responding accuracy remaining at 50 percent correct. Experiment three involved a conditional discrimination procedure, which was implemented to find out whether the possums could in fact discriminate between a horizontal and vertical light. All the possums in this experiment reached 80 percent correct overall and at responding to either a horizontal or vertical light. These results are enough to conclude that it was not the stimuli used in the previous two experiments which that had been causing the difficulties but the task itself. It is not known exactly why the possums were so unsuccessful in performing a DMTS or MTS task. More research into DMTS in possums in greatly needed and would offer a better understanding of the results of this study.