Self-Explanatory Objects: An Investigation of Object-Based Help

The thesis describes an investigation of on-line help provision for computer systems that have graphical object-oriented interfaces. It concentrates on object-based help facilities and describes the development of a method for obtaining object-based help information and the identification of useful types of object-based help information. The thesis demonstrates that it is both possible and practical to obtain object-based help information from the code of an appropriately programmed main system, and it describes observational studies that showed the usefulness of some types of object-based help information. The approach that was taken involved implementing two systems in object-oriented programming styles. Both systems have graphical object-oriented interfaces' and object-based help facilities. The object-based help facilities provide information about the objects displayed by the interfaces when the display objects are indicated. The object-based help information is drawn from system objects which are coded components of the systems. This method is practical when there are one-to-one correspondences between display objects and the system objects that generate and maintain them. The term 'self-explanatory objects' denotes system objects that have been written to be used as a source of object-based help information in this way. The first system is a simple proof-of-concept prototype in the form of a noughts and crosses game. The second system, a game of strategy called Partickles, includes both object-based and menu-based help. The usage of Partickles' help facilities was investigated in a series of three successive studies conducted with a total of nineteen school students aged 12 to 18. Evidence from the studies has shown the usefulness of menu-based overviews and reference facilities, and of object-based help information that explains what display objects would do if activated in the current context. The results include suggestions for implementing help facilities based on self-explanatory objects, a set of guidelines for the provision of help in systems that have graphical object-oriented interfaces, a framework for the provision of object-based help and four types of information that can be used as a template for object-based help messages

Experimental influence of pH on the early life-stages of sea urchins I: different rates of introduction give rise to different responses

Many early life-stage response studies to ocean acidification utilize gametes/offspring obtained from ambient-sourced parents, which are then directly introduced to experimentally altered seawater pH. This approach may produce a stress response potentially impacting development and survival. Hence, this study determined whether this approach is suitable by subjecting embryos/larvae to different rates of introduction to lowered seawater pH to assess larval success under acute and staggered experimental pH scenarios. Embryos and 4-armed larvae of the sea urchin Psammechinus miliaris were introduced to pH conditions, widely used in ocean acidification studies, from ambient conditions utilizing 380, 470, 560, 700 and 840 ppm CO2 changed at incremental steps at two rates: fast (every 3rd hour) or slow (every 48th hour). Direct transfers from ambient to low seawater pH gave rise to dramatic negative impacts (smaller size and low survival), but slower rates of introductions gave rise to lesser negative responses (low survival). There was no treatment effect on settled juveniles. Fast introductions utilized in many studies are likely not ideal approaches when assessing pre-settlement larval developmental responses. Therefore, careful consideration of the pattern of response is needed when studies report the responses of offspring, derived from ambient conditions, introduced directly to forecasted ocean acidification conditions

Age-related thermal response: the cellular resilience of juveniles

Understanding species’ responses to environmental challenges is key to predicting future biodiversity. However, there is currently little data on how developmental stages affect responses and also whether universal gene biomarkers to environmental stress can be identified both within and between species. Using the Antarctic clam, Laternula elliptica, as a model species, we examined both the tissue-specific and age-related (juvenile versus mature adult) gene expression response to acute non-lethal warming (12 h at 3 °C). In general, there was a relatively muted response to this sub-lethal thermal challenge when the expression profiles of treated animals, of either age, were compared with those of 0 °C controls, with none of the “classical” stress response genes up-regulated. The expression profiles were very variable between the tissues of all animals, irrespective of age with no single transcript emerging as a universal biomarker of thermal stress. However, when the expression profiles of treated animals of the different age groups were directly compared, a very different pattern emerged. The profiles of the younger animals showed significant up-regulation of chaperone and antioxidant transcripts when compared with those of the older animals. Thus, the younger animals showed evidence of a more robust cellular response to warming. These data substantiate previous physiological analyses showing a more resilient juvenile population

Exploring Explanations of Subglacial Bedform Sizes Using Statistical Models

Sediments beneath modern ice sheets exert a key control on their flow, but are largely inaccessible except through geophysics or boreholes. In contrast, palaeo-ice sheet beds are accessible, and typically characterised by numerous bedforms. However, the interaction between bedforms and ice flow is poorly constrained and it is not clear how bedform sizes might reflect ice flow conditions. To better understand this link we present a first exploration of a variety of statistical models to explain the size distribution of some common subglacial bedforms (i.e., drumlins, ribbed moraine, MSGL). By considering a range of models, constructed to reflect key aspects of the physical processes, it is possible to infer that the size distributions are most effectively explained when the dynamics of ice-water-sediment interaction associated with bedform growth is fundamentally random. A ‘stochastic instability’ (SI) model, which integrates random bedform growth and shrinking through time with exponential growth, is preferred and is consistent with other observations of palaeo-bedforms and geophysical surveys of active ice sheets. Furthermore, we give a proof-of-concept demonstration that our statistical approach can bridge the gap between geomorphological observations and physical models, directly linking measurable size-frequency parameters to properties of ice sheet flow (e.g., ice velocity). Moreover, statistically developing existing models as proposed allows quantitative predictions to be made about sizes, making the models testable; a first illustration of this is given for a hypothesised repeat geophysical survey of bedforms under active ice. Thus, we further demonstrate the potential of size-frequency distributions of subglacial bedforms to assist the elucidation of subglacial processes and better constrain ice sheet models

A fatal case of louping-ill in a dog: immunolocalization and full genome sequencing of the virus

Louping-ill (LI), caused by louping-ill virus (LIV), results in a frequently fatal encephalitis primarily affecting sheep and red grouse (Lagopus lagopus scotica), but it does occur in other species. An adult male Border collie dog was definitively diagnosed with fatal LI and the lesion profile, LIV antigen distribution and full genome sequence of the LIV responsible were investigated to determine if this differed significantly from sheep-derived LIV. No gross lesions were present. The histological lesions were confined to the central nervous system and comprised of lymphocytic perivascular cuffs, glial foci, neuronal necrosis and neuronophagia. Immunolocalization of viral antigen showed small amounts present in neurons only. These histological and immunohistochemical findings were similar to those reported in affected sheep. Compared with published full genome sequences of sheep-derived LIV, only very minor differences were present and phylogenetically the virus clustered individually between a subclade containing Scottish strains, LIV 369/T2 and G and another subclade containing an English isolate LIV A. The LIV isolated from the dog shares a common progenitor with LIV A. These findings suggest there is no canine-specific LIV strain, dogs are susceptible to sheep-associated strains of LI and with the increase in tick prevalence, and therefore exposure to LIV, a safe, effective vaccine for dogs may be required

Relativistic many-body calculations of electric-dipole matrix elements, lifetimes and polarizabilities in rubidium

Electric-dipole matrix elements for ns-n'p, nd-n'p, and 6d-4f transitions in Rb are calculated using a relativistic all-order method. A third-order calculation is also carried out for these matrix elements to evaluate the importance of the high-order many-body perturbation theory contributions. The all-order matrix elements are used to evaluate lifetimes of ns and np levels with n=6, 7, 8 and nd levels with n=4, 5, 6 for comparison with experiment and to provide benchmark values for these lifetimes. The dynamic polarizabilities are calculated for ns states of rubidium. The resulting lifetime and polarizability values are compared with available theory and experiment.Comment: 8 pages, 2 figure

$p+^{4,6,8}He elastic scattering at intermediate energies

Using a relativistic nuclear optical potential consisting of a Lorentz scalar, $V_{s}$, and the time-like component of a four-vector potential, $V_{0}$, we calculate elastic scattering differential cross sections and polarizations for $p+^{4}$He at intermediate energies for which experimental data are available. We also calculate the differential cross sections and analyzing powers for $p+^{6,8}$He at intermediate energies and compare with the few available experimental data.Comment: 09 pages, 04 figure

Physician diagnosed arthritis, reported arthritis and radiological non-axial osteoarthritis

SummaryObjectiveTo determine the question that best predicts radiographic evidence of non-axial osteoarthritis (OA).DesignThe Melbourne Women's Mid-life Health Project (MWMHP), commenced in 1991, is a population-based prospective study of 438 Australian-born. Two hundred and fifty-seven (57%) women remained in longitudinal assessment in 2002 and 224 (87%) women agreed to undergo X-rays of their hands and knees between 2002 and 2003.MethodsAnnually participants were asked about aches and stiff joints and arthritis or rheumatism. In the eleventh year of follow-up X-rays were scored for evidence of OA using a validated scale, by two investigators who were blinded to questionnaire results. Information on hormone therapy use, physical activity, mood, smoking, body mass index (BMI) and age were obtained by both self-administered and face-to-face questionnaires.ResultsPatient reported physician diagnosed arthritis was the best predictor of radiological OA (ROA). The question had a specificity of 64%, a positive predictive value of 57% and a negative predictive value of 71%. Even the most reliable question about arthritis still had a relatively low specificity for radiologically diagnosed OA. Reporting symptoms were significantly more common in participants who were depressed, those who had a higher negative affect and those with a higher BMI.ConclusionIn large epidemiological studies where questionnaire assessment of OA is required, the greatest accuracy is achieved by asking about physician diagnosed arthritis. Concurrent application of a validated scale for mood is important