A basis for the exploration of hypermedia systems : a guided path facility : a thesis presented in partial fulfillment of the requirements for the degree of Master of Arts at Massey University

This thesis examines the potential of a paths facility as an aid to navigating large hypermedia systems. The use of the navigational metaphor as applied to finding information is continued with the idea of following a path through information 'space'. This idea assumes that each node, or chunk of information, on the path can be considered a landmark that can be easily returned to when side-trips are taken off the path to explore the surrounding space. The idea of a guided path assumes the re-use of a path, and also assumes that there is extra information available about the path. This meta-information is very important for providing information to help path-followers make better sense of the path, both in terms of content and context, but also in making more effective use of the nodes on the path and in navigating the variety of interface conventions seen in the test environment - HyperCard. A small pilot study has been carried out using two groups of users performing a directed information-seeking task. One group used HyperCard's navigational facilities to find information in a group of stacks, while the other group used a guided path as a base on which to explore the same group of stacks. Both groups had a time limit, at the end of which they completed a number of questionnaires to indicate task completion, as well as providing a subjective evaluation of the facilities they used. The guided path facility appears to be most effective for inexperienced users for a number of reasons. It presents a simplified view of the complex system - the information available has already been filtered and selected, and a simple and consistent navigational interface reduces the cognitive overheads associated with learning a variety of mechanisms present in different stacks. An important feature of a path facility seems to be the provision of meta-information, especially scope information which can reduce the incidences of disorientation. Another feature is the provision of a history facility which provides a backtracking capability. It may also be used in the creation of paths using the length of visit as a criterion for node inclusion on a new path

Prospects for productive use of saline water in West Asia and North Africa

Water quality / Salinity / Soil salinity / Irrigated farming / Crop production / Feed crops / Fodder / Poverty / Public policy / West Asia / North Africa / Egypt / Jordan / Syria / Tunisia

Covalent bonding effects in diffraction from amorphous solids

Imperial Users onl

Reactive transport and fluid pathways in fracture-controlled flow systems

This thesis uses mapping and analysis of C/O stable isotopes to explore the distribution and evolution of fracture-controlled fluid flow in two vein-rich, limestone-hosted fault systems: The Dar Al Baydha (DAB) Fault system in northern Oman and a network of low-displacement faults in the Helvetic Alps, Switzerland. The DAB Fault is 25km long and has a maximum throw of >750m. There is also a subordinate, low displacement fault network formed adjacent to the DAB Fault. This study has explored a segment of that network in the Hail Ash Shas area (HAS network). In the Helvetic nappes, work has predominantly focused on a late to post-nappe emplacement fault network. Most faults in this network cannot be traced beyond a single outcrop and typically have throws 25.5 per mil) to 13.7 per mil. In the Helvetics, d18O compositions of vein calcite vary from host rock values (>19 per mil) to 10.6 per mil. The extent of 18O-depletion in both systems can be caused only by influx of fluids from one or more external reservoirs with d18O compositions that are in disequilibrium with the host rock. Reactive transport modelling indicates that the DAB Fault has a time-integrated-fluid-flux (TIFF) of 100,000mol/cm2, whereas the HAS network has a modelled TIFF of 1,000,000mol/cm2. In comparison, the Solalex network (in the Helvetic nappes) has an estimated TIFF of 500mol/cm2 . While externally-sourced fluids infiltrated the DAB Fault along much of its strike length, the distribution of strongly 18O depleted vein compositions in the DAB Fault system indicates a very heterogeneous distribution of high fluid flux. Structural features such as some segment boundaries and termination zones locally hosted high fluid fluxes. However, this relationship is not ubiquitous and varies with time. This highlights the 4D complexity of fluid pathways in the DAB Fault. The TIFF estimate for the HAS network is an order of magnitude greater than for the DAB Fault. This demonstrates the effectiveness of low displacement fault networks for fluid transport, even when they are proximal to large co-active faults. The high pore fluid factors and complex hydraulic connectivity in this fault network suggests that it may have predominantly evolved as an invasion percolation network. In contrast to the DAB Fault, the network of faults in the Helvetic nappes has much lower modelled TIFF. However, the limited spatial extent of faults and apparent lack of 2D geometric connectivity, combined with the evidence for transport distances >1km again highlights the complexity of 3D hydraulic connectivity and indicates that relatively immature fault systems can still effectively drain overpressured reservoirs

Mary Somerville's Early Contributions to the Circulation of Differential Calculus

In 1831, with the publication of her translation of Laplace’s Mecanique Celeste, Mary Somerville (1780--1872) solidified her reputation throughout Western Europe as a highly proficient mathematician, and an expert in `French analysis’. To shed light on her preliminary studies, we here examine Somerville’s earliest known mathematical work, namely her published and unpublished solutions to questions posed in the New Series of the Mathematical Repository, alongside her contemporary correspondence with mathematicians John and William Wallace. These submissions demonstrate her active engagement in the circulation of the differential calculus twenty years earlier than previously appreciated

Exposé of Polygamy

After the 1872 publication of Expose',Fanny Stenhouse became a celebrity in the cultural wars between Mormons and much of America. An English convert, she had grown disillusioned with the Mormon Church and polygamy, which her husband practiced before associating with a circle of dissident Utah intellectuals and merchants. Stenhouse’s critique of plural marriage, Brigham Young, and Mormonism was also a sympathetic look at Utah’s people and honest recounting of her life. Before long, she created a new edition, titled "Tell It All," which ensured her notoriety in Utah and popularity elsewhere but turned her thoughtful memoir into a more polemical, true expose' of Polygamy. Since 1874, it has stayed in print, in multiple, varying editions. The original book, meanwhile, is less known, though more readable. Tracing the literary history of Stenhouse’s important piece of Americana, Linda DeSimone rescues an important autobiographical and historical record from the baggage notoriety brought to it

The Invention of Papal History: Onofrio Panvinio between Renaissance and Catholic Reform

Stefan Bauer, The Invention of Papal History: Onofrio Panvinio between Renaissance and Catholic Reform, Oxford, Oxford University Press, Oxford-Warburg Studies, 2020, 288 págs., ISBN 978-0-19-880700-1 [Reseña]Stefan Bauer, The Invention of Papal History: Onofrio Panvinio between Renaissance and Catholic Reform, Oxford, Oxford University Press, Oxford-Warburg Studies, 2020, 288 págs., ISBN 978-0-19-880700-1 [Book review

Cervico-Facial and Intra-Oral Actinomycosis

Actinomycosis was first recognized as a specific disease late in the 19th century. Confusion os to the nature of the infecting micro-organism and the mode of its entry into soft tissue led to two diverse theories on the pathogenesis. On the one hand it was believed that the microbe was an aerobic species which grew on agricultural land and which was introduced to the body from the habit of grass or straw chewing, whilst on the other hand the organism was held to exist as a commensal in the oral cavity which could under certain circumstances become an active pathogen. Many investigators contributed to these basic arguments, but the overwhelming weight of evidence came down on the side of the endogenous theory. Despite this, many texts still perpetuate this misconception. Cervico-facial actinomycosis is the most common site of the disease, and it is most prevalent in the second and third decades affecting males more frequently than females in a ratio of approximately 2 to 1. There is a close association between the teeth and cervicofacial actinomycosis. The vast majority of cases are related either to an apical dental abscess or follow some form of oral trauma, usually an extraction. Two clinical variants of the disease can be recognized. The acute infection is often related to a septic tooth and is shown to affect a younger age group, whereas the chronic infection more often is a sequel to an extraction and affects an older age group. In both groups, the lower molar region is predominantly involved. The diagnosis of actinomycosis involves a combination of astute clinical awareness and microbiological technique. The use of specific fluorescent antiserum in the diagnosis of cervicofacial actinomycosis is shown to be of value in the early recognition of the disease, thus allowing the clinician to formulate and implement correct therapeutic drug regimes at an early stage. The value of bacteriological examination of intra-oral specimens is highlighted as is the limitation of diagnosis from formalin fixed material. Treatment of cervico-facial actinomycosis involves a combination of surgery and antibiotic therapy, normally penicillin. The difficulty of laying down rules on the duration of therapy is clear, since each case requires individual assessment. The host reaction to actinomycotic infection is a fibrosis which may lead to scar formation on resolution. Investigations into the occurrence of actinomyces in relation to bony sequestra may be an indication of the mechanism by which the organisms gain access to the soft tissues, and the frequency with which the lower molar region is implicated. Although actinomycosis in bone is rare, the sequestrum may provide a suitable environment for these bacteria to thrive before invading the soft tissues which have been opened to the infection by the fracture of the buccal or lingual alveolar bone which originally provided the sequestrum. Logically, the bacterial population of the dental plaque in the lower molar area must be considered and investigations showed that A. israelii is present in larger numbers in this area than in the anterior region of the mouth. This study also indicated that A. israelii is more prevalent than A. naeslundii per unit volume of plaque in both anterior and posterior regions and in total numbers. A. naeslunaii showed no significant difference in numbers anteriorly compared with posteriorly. Studies on the flora obtained from the fitting surfaces of upper dentures in edentulous subjects confirmed the close relationship between actinomyces and the natural dentition. Finally, it was shown that in vitro, polymorphonuclear leucocytes were able to ingest both cocco-bacillary and filamentous forms of actinomyces. The impediment to more rapid resolution of the infection would hence appear to lie elsewhere. Excessive fibrous walling off by the host tissue does offer one explanation for this slow healing response particularly in the more chronic form of the disease. Furthermore, the "sulphur granule" itself may act as an effective barrier to successful phagocytosis. Actinomycosis in the oro-facial region remains a fascinating disease to the medical and dental professions. It is one of the few pyogenic infections in the area which can be attributed to a specific bacterium. Most abscesses of the jaws are found to be due to a mixture of pathogens, and actinomycosis is no exception. The isolation of actinomyces, however, forewarns the clinician of the likelihood of persistence and a marked fibrotic reaction from the host tissues. Its early diagnosis is of paramount importance to treatment, and although the disease is comparatively rare, in the words of W. D. Miller written as long ago as 1890 "We consequently have here again another dangerous source of infection in the human mouth, which the dentist and physician do well not to lose sight of."