Journal and Proceedings of
The Royal Society of New South Wales
Volume 136 Parts 1 to 4
Publish and Perish
Pesidential Address - 2003
David A. Craddock
Abstract: Two major celebrations will occur during this year, 2003. The first is the bicentenary of the publication of the first Australian newspaper, the `Sydney Gazette and NSW Advertiser.' The other major event will be celebrated at the end of 2003, with the centenary of powered, controlled and sustained human flight. Although the Wright Brothers' flight was an American success, their achievement was initially based on the work of other pioneers. The work of those earlier pioneers became available to the Wrights through the medium of print. This paper explores some of the Australian linkages between the written word and those early aerial endeavours.
Keywords
Australian aviation, Lawrence Hargrave, Wright Brothers, human flight
Thermal Induction, Salt Treatment and the associated Plumule/Radicle Growth Response of Sorghum at 42/19°C
M.A. Kader
Abstract: This investigation tested the influence of thermal induction of seeds at various stages of imbibition prior to exposure to heat shock on the germinative and growth response of those seeds and seedlings. Seeds of sorghum (Sorghum bicolor L. Moench) were treated in 2, 4 or 6 g NaCl/L solutions and exposed for 2 hours to 45 °C during the first, second or third days of imbibition (thermal induction). Thereafter, seeds were dried and germinated at 42/19 °C (day/night temperature). Salt treatments did not improve the final germination percentage but increased germination speed over untreated seeds. The higher the salt concentration used, the greater the dry weights of plumules (shoots) and radicles (roots). Thermal induction on the third day of imbibition yielded higher germination percentages than un-induced seeds, while induction on the second day gave faster germination. Both the second and third day induction treatments gave superior germination indices and higher plumule to radicle ratios. It is concluded that thermal induction may assist in acclimating seeds to heat stress.
Keywords
Thermal induction, stress, germination, growth
`The Celluloid Strip' - Mass Screening for Tuberculosis in New South Wales, 1950-1975
Dr Peter J. Tyler
Abstract: Tuberculosis was a significant cause of mortality at the beginning of the Second World War when the technique of taking miniature X-ray photographs on movie film was introduced to Australia as part of the medical examination of men enlisting in the armed forces. Immediately after the war, the Anti-Tuberculosis Association of NSW expanded its existing diagnostic clinic in Sydney to provide a mobile X-ray service to country areas and industry. That experience provided a model for the subsequent national campaign which the Commonwealth Government funded to detect and treat the disease.
Coincidentally, at the same time as the compulsory national screening program commenced, the first effective therapy for the disease became available. Antibiotic drugs soon achieved results that long periods of rest in a sanatorium had never accomplished. Government funding was withdrawn after the incidence of tuberculosis diminished, so that by 1975 the ubiquitous X-ray caravans began to disappear from street corners around Australia. This paper describes the logistics of the mass screening campaign during the third quarter of the twentieth century, and the technological developments that made it possible.
Keywords
tuberculosis, camera, radiography, screening, X-ray, Anti-Tuberculosis Association
Thesis Abstract: On a Dynamical Origin for Fermion Generations
Jim Bashford
Abstract of a Thesis awarded for the Degree of Doctor of Philosophy University of Adelaide, South Australia 2003
We investigate a proposal [Bass, S.D. and Thomas, A.W. Mod. Phys. Lett. A 11, 339, (1996)] addressing several outstanding shortcomings of the perturbative Standard Model of particle physics. Specifically a common, dynamical origin is hypothesised for the number of fermion generations, the spectrum of fermion masses and for Charge-Parity violating processes. The appeal of this proposal is that these features are a manifestation of the high-energy, non-perturbative sector of the Standard Model, requiring no new physics beyond presently attainable experimental limits. The problem is studied by two complementary approaches and a possible analogy with condensed matter physics.
Understanding of how the mass, generations and CP-violation might arise are first investigated in a toy four-fermion model. It is shown that different scale-invariant four-fermion operators are present for three sub-spaces of the full theory which can be arranged in a hierarchy of phases of a `fundamental' theory. This enables self-consistent introduction of three fermion generations. Mass `gap' equations are also derived and found to have non-trivial solutions above critical coupling strengths.
The second part of the thesis is concerned with the dynamical breakdown of chiral symmetry in the quenched hypercharge interaction. In particular we follow the successful procedure developed for quantum electrodynamics, proposing a 1-loop renormalisable vertex ansatz for solution of the fermion self-energy Dyson-Schwinger equation. In the absence of dynamical fermion-antifermion bound states it is found there exist two `mass gaps' indicating several modes of four-fermion pairing in the neighborhood of two critical coupling points. These `gaps' cannot be interpreted as physical fermion mass , illustrating a key difference between this theory and and studies of conventional chiral symmetry breakdown: Fermion pairing terms associated with the symmetry breaking are a necessary, but not always sufficient, requirement for dynamical mass generation. It is noted that similar behavior may occur in systems of strongly-correlated electrons where a `pseudo-gap', intermediate to superconducting and normal phases may be observed.
To this end we are motivated to suggest an new, alternative solution to the problem of criticality in the hypercharge theory. In particular a rearrangement of fermionic degrees of analogous to spin-charge separation in low-dimensional condensed matter physics is considered, leading to a new class of high-energy extensions of the Standard Model.
Dr Jim Bashford
School of Mathematics and Physics
University of Tasmania
Hobart, Tasmania 7001
Australia
Manuscript received: 23.10.2003
Thesis Abstract: Remotely Sensing Changes in the Vegetation of Ephemeral Wetlands
Simon N. Benger
Abstract of a Thesis awarded for the Degree of Doctor of Philosophy Australian National University 2002
The ephemeral wetlands of semi-arid Australia provide important habitats for many species and play a significant role in the hydrological and biological regimes of these environments. As most inland wetlands owe their existence to unregulated cycles of flooding and drying, many wetlands are now being forced into decline through flow regulation associated with irrigation for large, highly productive agricultural enterprises. This decline usually manifests itself through reductions in the spatial extent of vegetation stands, transitional effects in the landscape and a deterioration in the physiological condition of individual plants. A time-series of Landsat TM and JERS-1 optical and radar imagery were used to investigate the potential for employing various vegetation species as remotely sensed indicators of wetland decline in the Macquarie Marshes of central western New South Wales. The research examined the utility of remotely sensed imagery for the mapping of semi-arid inland wetland vegetation and assessed its effectiveness in detecting changes in the physiological health of wetland vegetation due to alterations in the hydrological regime.
Four species, river red gum Eucalyptus camaldulensus, cumbungi reed Typha orientalis, common reed Phragmites australis, and water cooch Paspaulum paspalodes could be detected at sufficient spatial and spectral resolution to be mappable from satellite imagery. All of these species showed changes in spectral characteristics and radar response as a result of reduced flooding of the wetlands. Two of the species examined, cumbungi reed and common reed, worked well as indicators of short term changes in water availability by manifesting loss of spatial extent and reduction in NDVI. River red gum stands were excellent indicators of longer term decline due to their relative permanence in the landscape and longer response to changes in water availability, while the condition of water cooch pastures was also a good indicator of wetland condition. The development of these techniques offers good potential to facilitate monitoring of the physiological health of inland wetlands and assist in management decisions regarding flow regulation and flood control.
Automated vegetation classification proved to be very accurate in mapping both spatial extent and identity of vegetation types. Transitional landscapes which result from changes in the hydrological regime of the wetlands could also be clearly differentiated from their origins. Degradation of indicator communities also showed up well in the results, causing dramatic changes in NDVI response on a seasonal basis. Characteristic response patterns were revealed for all the indicator species examined, and suggest that NDVI based monitoring would be very effective in an environment where these indicators were present. Analysis of JERS-1 L-band radar imagery over the study area clearly showed that structure is a primary determinant of backscatter. Structural declines due to vegetation alteration were evident in terms of reduced radar returns, which are most significant in defining transitions from river red gum forests to river red gum woodlands and conversion of water cooch pastures through to mixed grassland and then chenopod dominated landscapes. Flood mapping and modelling from optical and radar imagery were also explored in the study and results showed that there is substantial potential for the use of automated flood mapping and modelling in inland wetland environments.
Dr Simon N. Benger
Lecturer in Spatial Informations Systems
University of Canberra
ACT 2601
Manuscript received: 02.09.2003
Thesis Abstract: Temporomandibular Joint: Form and Function
George J. Dias
Abstract of a Thesis awarded for the Degree of Doctor of Philosophy University of Otago, New Zealand 2003
The human temporomandibular joint (TMJ) is susceptible to dysfunction, the etiology of which is poorly understood or unknown. This thesis investigates certain aspects of the form and function of this joint and related structures, with a view to acquiring a better understanding of its disorders.
In considering whether the morphology of the human TMJ, together with the masticatory complex as a whole, adapts to the masticatory environment, two groups of Kuni Kuni pigs were used, one on a hard diet and the other on a soft diet. With a hard diet, there appears to be a shortening of both the mandible and maxilla. It is argued that these findings, in conjunction with the results of other similar studies may challenge the popularly-held view that the relatively soft diets of modern urbanised populations have brought about a reduction in the size of the jaws.
The morphology of the lateral pterygoid muscle was investigated, since it has a major influence on the functional anatomy of the TMJ. Contrary to the accepted view, it was found that the lateral pterygoid muscle consists of three heads of origin - a lower head, an upper head, and a newly described uppermost head. This uppermost head is situated lateral to the upper head and has a vector of force directed lateral to the vector of the upper head.
In an attempt to address the presence of a true antagonist to Bennett movement and to explain the medial dislocation of the disc, an inferior dissection approach to the joint was adopted. A near horizontal band of tissue, consisting of a varied mix of striated muscle bundles interspersed with fibrous tissue and vascular channels, was found in the posteromedial aspect of the mandibular condyle. This is termed the glenomandibular muscle band. It is concluded that this is responsible for producing antagonistic force for the Bennett movement, and is also responsible for the pure medial dislocation of the disc.
Plain film radiographic images have had a major influence on our understanding of TMJ morphology. Despite TMJ imaging?s long history of research and clinical application, the quality of information gathered from imaging is often less than desired. Therefore, it may be clinically useful if a method can be developed that can generate data closer to actual joint values, thereby enabling clinicians to make a better informed qualitative assessment of TMJ morphology. This investigation revealed that the more clinically-important larger joint measurements are significantly different between actual joint specimens, and those of the respective oblique lateral transcranial and true lateral radiographs. A novel approach employing a `neural network' to improve the accuracy of routine plain film radiographs is outlined and tested.
The above findings, that the jaws adapt to the functional environment, that there are hitherto unknown contractile elements acting on the joint, and the ability to improve the qualitative information from routine joint images would in addition to improving knowledge of the form and function of the TMJ and the masticatory complex, lead to a better understanding of TMJ disorders.
Dr George J. Dias
Department of Anatomy and Structural
Biology, School of Medical Sciences,
University of Otago
PO Box 913, Dunedin 9001
New Zealand
Manuscript received: 09.09.2003
Thesis Abstract: Crescentic Glomerulonephritis: Associations and Transforming Growth Factors
Harold J. Neal
Abstract of a Thesis awarded for the Degree of Doctor of Philosophy
University of Otago, New Zealand 2003
The initial aim of this project was to study the role of mast cells in anti-glomerular basement membrane antibody (anti-GBM) induced crescentic glomerulonephritis (CGN), using experimental autologous, and accelerated autologous rabbit models. A method of biopsy was developed to allow sequential sampling of the kidneys over time, and reduce the number of rabbits required for study,
Early in the project, a significant influx of tissue eosinophilic cells were noted during the progression of the disease, and coincided with the onset of the autologous phase. The study of eosinophil in CGN became the major focus of the project, and early results led to the hypothesis that eosinophils have a relationship GN, and that they may have an association with the fibrotic process by producing certain cytokines such as transforming growth factor (TGF-α) and beta (TGF-β), both of these cytokines being demonstrated by other workers as having direct roles in several scaring and sclerotic conditions.
Using biochemical techniques, light microscopy, transmission electron microscopy, and immunohistochemistry, the eosinophilic cells were confirmed as true eosinophils, and not rabbit heterophil (neutrophil) which has similar morphological features to the eosinophil.
Qualitative and quantitative assessment demonstrated that tissue eosinophils did occur at the onset of the autologous phase, and that they first appeared at, and around, the glomerular vascular pole region. As the glomerular crescents developed, the eosinophils were observed both within the crescents (intracrescentic), and in the interstitium circumscribing the crescent (pericrescentic). Eosinophils were very scant and insignificant in control groups.
The number of eosinophils observed with each individual crescent was associated with the degree of pathological change of the diseased glomerulus, the influx of macrophages, the deposition of collagen within crescents, and glomerular area. An increase in the number of macrophages was also seen in the heterologous phase of the autologous models , preceding the influx of eosinophils at the onset of the autologous phase.
The accelerated autologous model has many similar morphological features to rapidly progressive CGN observed in human renal biopsies, and an audit of human cases was undertaken, The intracrescentic and pericrescentic distribution of eosinophils in human CGN was similar to that observed in the rabbit autologous model. There was also a significant association of eosinophil score with the deposition of collagen within crescents.
Eosinophils in approximately one third of human biopsies were positive for TGF-α and TGF-β1 proteins. A sequential expression of the two cytokines by red blood cells and fibrin was also seen. The nuclei of some crescentic fibroblasts showed positive TGF-β1 protein expression.
The results of combined experimental animal research and audited human renal biopsies show significant associations between tissue eosinophils, fibrosis of glomerular crescents, and TGF-α and TGF-β1 proteins. These findings indicate avenues towards further study, and potential pathways for therapeutic intervention. Important considerations are also raised regarding prior research with experimental ant-GBM antibody CGN in rabbits, in which eosinophils may have been `neglected', but could influence research outcomes in the pathogenesis of this animal model of such a debilitating human disease.
Dr Harold J. Neal
12 Armack Drive
RD5, Christchurch 8021
New Zealand
Manuscript received: 11.09.2003
Thesis Abstract: Dynamics of outbreak populations of crown-of-thorns starfish (Acanthaster planci L.), and their effects on coral reef ecosystems
Morgan S. Pratchett
Abstract of a Thesis awarded for the Degree of Doctor of Philosophy in Marine Ecology James Cook University, Townsville, Queensland 2002
Population outbreaks of crown-of-thorns starfish (Acanthaster planci L.) represent one of the most significant biological disturbances affecting coral reef ecosystems. This study examined fine-scale patterns in the size-structure, distribution, and abundance of starfish, during an outbreak at Lizard Island, in the northern Great Barrier Reef. The outbreak resulted from a steady and prolonged increase in starfish densities over several years (1994-1997), with progressive accumulation of starfish from multiple recruitment events. Reef-wide densities of A. planci increased to a maximum of 1.0~starfish per 200 m2 (±0.1 SE), in January 1997, and then remained fairly constant until June 1998, after which time starfish densities declined rapidly. Starfish densities varied greatly among locations (separated by 0.5-8 km), and also between reef zones (<5m apart). Fine-scale patterns in the distribution and abundance of A. planci were partly attributable to spatial variation in wave exposure (whereby starfish avoid turbulent environments), but also resulted from spatial variation in recruitment.
Outbreak populations of A. planci caused substantial coral mortality, and significantly altered community structure of corals. However, the impacts of A. planci were very patchy. At the most severely affected locations (back-reef habitats) coral cover declined by 72% between 1996 and 1999, whereas at several other locations (e.g., lagoonal habitats) there was no observable change in scleractinian coral cover. Crown-of-thorns starfish also had varying impacts among different coral species, caused by significant selectivity in their patterns of feeding. In general, starfish had a disproportionate impact on fast growing branching corals (e.g. Acropora spp. and pocilloporids), tending to avoid slow growing massive corals (e.g. Diploastrea spp., Porites spp.).
Clearly, crown-of-thorns starfish have a major impact on coral communities, but impacts of starfish outbreaks also extend to a wide range of reef associated organisms, such as coral reef fishes. This study examined long-term changes in the distribution and abundance of Chaetodon butterflyfish and coral-dwelling damselfish, during the course of the crown-of-thorns outbreak. Depletion of scleractinian corals resulted in significant reductions in the abundance of seven butterflyfish species (Chaetodon auriga, C. citrinellus, C. kleinii, C. plebius, C. rainfordi, C. trifascialis, and C. unimaculatus), whereas there was no change in the abundance of C. aureofasciatus, C. baronessa, C. ephippium, C. lunulatus, C. melannotus or C. vagabundus. Chaetodon species affected by coral depletion mostly had a high dependence on live coral for food. However, at least one non-coral feeding butterflyfish, C. auriga, was also affected. Among corallivorous butterflyfish, impacts of coral depletion varied in accordance with their degree of feeding specialisation. Similarly, some species coral-dwelling damselfish were affected (Chromis viridis, Dascyllus aruanus, D. reticulatus and Pomacentrus moluccensis), but not others (C. atripectoralis and P. amboinensis). Damselfish species not affected (C. atripectoralis and P. amboinensis) often inhabited skeletons of dead corals, whereas all other species were strongly dependent on live coral as shelter. This study demonstrates that major disturbances to coral reef habitats can have significant follow-on affects for reef fishes. However, the specific responses of individual species vary in accordance with their diet, habitat preference, distribution, abundance and ecological versatility.
Dr Morgan S. Pratchett
School of Marine Biology and Aquaculture
James Cook University
Townsville, Queensland 4811
Manuscript received: 7.10.2003
Thesis Abstract: Microstructural Characterization of Nanocrystalline Fe-Zr-B(-Cu and/or Ge) Soft Magnetic Alloys
Deming Zhu
Abstract of a Thesis submitted for the Degree of Master of Engineering Science (Research) Monash University, Australia 2003
In the research presented in this thesis, the origins of the microstructure and solute partitioning behaviour are characterized in nanocrystalline Fe-Zr-B(-Cu and/or Ge) alloys in order to design new experimental soft magnetic alloys. The structural and microstructural evolution of nanocrystalline Fe93-x-yZr7BxCuy alloys (x = 3 and 9 at. %; y = 0 and 1 at. %) was examined, with the aim of investigating the effect of B and Cu additions. The effect of Ge on the microstructural and magnetic properties of Fe89-xZr7Bi3Cu1Gex (x = 0 to 5 at. %) alloys was also examined. The experimental techniques used in this research were differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning transmission electron microscopy (FESTEM) with nanoprobe energy-dispersive X-ray spectroscopy (NanoEDXS), and dc B-H loop tracer analysis.
In the investigation of the structural and microstructural evolution of nanocrystalline Fe93-x-yZr7BxCuy alloys, the following findings were made. B and Cu play opposite roles in stabilising the amorphous phase. While the addition of B stabilises the amorphous phase, the addition of Cu destabilises it. Cu atoms act as heterogeneous nucleation sites for the primary crystallization and the enhanced nucleation rate leads to nanocrystallites of bcc Fe in both low and high B content alloys. In high B content alloys, the crystallization of the amorphous phase occurs through two distinct reaction stages of amorphous --> bcc Fe + residual amorphous --> α-Fe + Fe2Zr + Fe3Zr. The ease with which the residual amorphous phase transforms into Fe-Zr based compounds is dependent upon Cu content. In Cu-free high B alloy, both the primary crystallization and secondary crystallization have similar kinetics, and the primary crystallization is immediately followed by the secondary crystallization. However, in the presence of Cu, the enhanced nucleation of bcc Fe alters the composition of the residual amorphous phase and thus delays the onset of secondary crystallization. In Cu-free high B alloy, the grain growth of Fe crystallites was observed. This is attributed to the formation of Fe-Zr based compounds, which consumes Zr atoms. In Cu-containing high B alloy, due to the absence of such a reaction, Zr atoms are effective in pinning the bcc Fe grain boundaries giving rise to the nanocrystalline microstructure. NanoEDXS studies show the enrichment of Zr at bcc Fe grain boundaries confirming the proposed grain refinement process.
In the investigation of the microstructural and magnetic properties of Fe89-xZr7B3Cu1Gex alloys, the following findings were made. The onset temperatures of primary crystallization for amorphous Fe89-xZr7B3Cu1Gex alloys are independent of the Ge content, but the Curie temperatures of these alloys are close to room temperature and increase with increasing Ge content. The crystallization takes place through two stages of amorphous --> bcc Fe + residual amorphous --> α-Fe + Fe3Zr regardless of Ge content. When the alloys are annealed for 3.6 ks at temperatures between 773 and 923 K, the microstructure consists mainly of bcc Fe crystallites with an average grain size of 11 to 13 nm embedded in the amorphous matrix. Ge is enriched in the residual amorphous matrix together with Zr. This increases the Curie temperature and the exchange stiffness in the intergranular region, thereby improving the soft magnetic properties. The coercivity of Fe89-xZr7B3Cu1Gex alloys annealed for 3.6 ks at 773 and 823 K exhibits a tendency to decrease with increasing Ge content, but this effect is not evident at 873 K and 923 K due to the relatively small volume of the residual amorphous phase. The coercivity of Fe89-xZr7B3Cu1Gex alloys annealed for 24 h at 923 K exhibits a tendency to increase rapidly, due to the formation of the more strongly anisotropic Fe3Zr compound and the enhancement of the grain size (55-60 nm).
Deming Zhu
School of Physics and Materials Engineering,
Monash University
Victoria 3800
Australia
Manuscript received: 21-08-2003