Journal and Proceedings of The Royal Society of New South Wales
STUDENT THESES ABSTRACTS IN VOLS 123-132 (Part 4 of 5: VOLS 129-130)
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CONTENTS
(in chronological order of publication)
| 1984-1990 [v118 pts 1-2 to v122 pts 3-4] | |
| Go to Theses Abstracts Archive Part 1 | |
| 1990-1993 [v123 pts 1-2 to v126 pts 3-4] | |
| Go to Theses Abstracts Archive Part 2 | |
| 1993-1994 [v127 pts 1-2 to v128 pts 3-4] | |
| Go to Theses Abstracts Archive Part 3 | |
| 1996 [v129 pts 1-2] | |
| Bishop, Andrew C. | Towards a Crop Growth, Development and Yield Model for Lupinus angustifo1ius (Narrow leafed lupin) in Tasmania |
| Borer, Philippe | The Twenty-Four Caprices of Niccolo Paganini: Their Significance for the History of Violin playing and the Music of the Romantic Era |
| Leung Sai-Wing | The Making of an Alienated Generation |
| Clements, Mark Alwin | Reproductive Biology in Relation to Phylogeny of the Orchidaceae, especially the Tribe Diurideae |
| Hayati, A. Majid | A Contrastive Analysis of English and Persian intonation Patterns |
| 1996 [v129 pts 3-4] | Haworth Robert J. | European Impact on Lake Sedimentation in Upland Eastern Australia: Case Studies from the New England Tablelands of New South Wales |
| O'Dea, Mark G. | Geometry and Structural Evolution of the Leichhardt River Fault Rough, Mount Isa terrain, Australia |
| Sekhon, Lali H.S. | The Effects of Chronic Cerebral Hypoperfusion in the Rat |
| Smith, Claire | Situating Style: an Ethnoarchaeological Study of Social and Material Context in an Australian Aboriginal Artistic System |
| 1997 [v130 pts 1-2] | |
| Brett, M. | The effect of tenure on range management |
| Frost, W.K. | The ecology of cereal rust mite Abacarus hystrix (Nalepa) in irrigated perennial dairy pastures in South Australia |
| Garrety, K. | Negotiating dietary knowledge inside and outside laboratories: the cholesterol controversy |
| Timmers, H. | Expressions of inner freedom: an experimental study of the scattering and fusion of nuclei at energies spanning the Coulomb barrier |
| 1997 [v130 pts 3-4] | |
| Christen, E.W. | The feasability of using mole drainage to control waterlogging in irrigated agriculture |
| Dawes, M.J. | Dying in prison: a study of deaths in correctional custody in South Australia 1980-1993 |
| Farr, Cynthia J.M. | The interface between syntax and discourse in Korafe, a Papuan language of Papua New Guinea |
| George, C.R.P. | The early development of clinical dialysis: the importance of symbolism in successful scientific endeavours |
| Hayes, Warwick J. | Chemical relationships in waters and sediments of some urban streams, with particular reference to heavy metals and phosphorus |
| Robinson, J.B. | Soil acidification in the Hunter Valley |
| 1998-1999 [v131 pts 1-2 to v132 pts 3-4] | |
| Go to Theses Abstracts Archive Part 5 | |
Vol 129 parts 1-2, p. 80 [1996] |
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Masters Thesis Abstract: Towards a Crop Growth, Development, and Yield Model for Lapinus angustifolius (Narrow Leafed lupin) in Tasmania
Andrew C. Bishop
Experiments were conducted between 1988 and 1990 at Elliott, Cressy, and Ross in Tasmania using three cultivars (Yandee, Geebung, and 75A329) of narrow-leafed lupin (Lupinus angustifolius). The purpose of these experiments was to examine narrow-leafed lupin growth and development in Tasmania in relation to specific environmental factors. These factors were related to growth and development measurements. It was hoped to use these relationships in a simple crop model suitable for assessing sites for the commercial production of lupins,
Preliminary experiments in 1988 examined the lupin cultivars for agronomic suitability in Tasmania. Increased grain yield was a function of more pods/m rather than increased pods/plant. This suggested that 1ower yields of the indeterminate line 75A329 could be compensated for by a higher plant density than in the indeterminate cultivars. Lupins responded to higher rainfall and extended growing season at Elliott thus outyielding crops at Cressy and Ross.
Detailed field experiments were conducted in 1989 and 1990 at Elliott and Cressy. Lupin crops developed very slowly in the first 8-10 weeks, and then grew rapidly after flowering was initiated. It appeared floral initiation was a function of higher temperatures and longer days in Yandee and 75A329, with further responses to vernalisation in Geebung.
Plant density significantly affected grain yield. 75A329 showed the largest yield responses to increased plant de¯sity, Although increased plant density resulted in increased leaf area, leaf senescence took place earlier in the highest density crops probably due to competitive effects. Optimum density for the indeterminate cultivars was 40 plants/m2. It may be higher for determinate cultivars. Low density crops were able to utilise their leaf area for light interception more efficiently than high density crops. In the latter, branches and leaves were pushed more towards vertical rather than horizontal thus less leaf area was presented to intercept light.
The study established that early sowing of lupins in Tasmania allows more time to grow and develop and yield more grain. A direct relationship was established between increased tota1 dry matter and increased grain yield.
The model developed in this study used thermal time as its only external factor to determine L, intercepted radiation (%), and total dry matter (kg/ha) during crop growth. From the predicted figure for total dry matter accumulated by harvest time, an estimate of potential grain yield could be made for that crop.
This study demonstrated the principle of collecting agronomic data and, guided by basic plant physiological principles and mathematical procedures, assembling simple sub-models that when linked can approximate a particu1ar aspect of crop growth.
An abstract from a thesis submitted to the University of Tasmania for the degree of Master of Agricultural Science, December 1994.
Vol 129 parts 1-2, p. 81 [1996] |
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Doctoral Thesis Abstract. The Twenty-Four Caprices of Niccolo Paganini. Their significance for the history of violin playing and the music of the Romantic era
Philippe Borer
This project attempts to describe and elucidate the compositional and instrumental character of the twenty-four Caprices of Niccolo Paganini and their far-reaching influence on violin playing and on musical creativity up to the present time. There is also the wider inspirational value which can be traced in literature, poetry and fine arts.
The first chapter aims to place the twenty-four Caprices in their historical perspective. The reception accorded to the work by prominent musicians of the time ( in particular Chopin, Liszt and Schumann) whose attention was drawn to the concept of virtuosity as an essential parameter in musical composition is examined.
Chapter 2 investigates the unique significance of the dedication "alli Artisti" which suggests a Romantic manifesto some ten years before Hugo's prefaces to Cromwell and to the Eastern Lyrics.
Chapter 3 investigates Paganini's instrumental and musical background. It has often been claimed that Paganini was self-taught. however, evidence of his all-important early training in vio1in and composition makes him the true heir of the old Italian masters, representing at the same time a vital milestone for subsequent development of instrumenta1 and compositional techniques. Paganini can thus be seen as representing a link between the classico-romantic and modern attitudes to instrumental writing, reaching well into the twentieth century.
In Chapter 4, some aspects of Paganini's compositional and performing styles are examined. A striking interpretative concept (the "suonare parlante") is discussed. Special consideration is given to instrumental techniques which are not employed in the Caprices. Their absence suggests that the Caprices represent a perhaps intentionally restrained statement of Paganini's violinistic knowledge.
Chapter 5 traces the origins of the violin Caprice and its developnent as a musical genre.
The appendices include an analysis of selected Caprices, a diplomatic transcript of Caprices 1-4, a facsimile of the manuscript, as well as supporting documents such as Feuilles d'album and scales written by Paganini.
Vol 129 parts 1-2, p. 82 [1996] |
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Doctoral Thesis Abstract: The Making of an alienated Generation
Leung Sai-wing
In this thesis, we argue that the four presuppositions of the consensus model of political socialisation are empirically unfounded. Neither are Marxist approaches to political socialisation supported by empirical evidence. We thus propose our dissensus mode1 of political socialisation: due to process variation, life cycle variation, generation variation, and social variation, the outcome of political socialisation could be dissensus. Likewise, socialisation of alienation is as equally possible as socialisation of allegiance. The so-called socialisation of alienation, our theoretical framework, refers to the accentuation of the socialisation process by political events such that people are sensitised to political reality and thus feel alienated.
From an historical review of political socialisation in Hong Kong in the past four decades, we found that because of the immigrant nature of Hong Kong population, there was an anti- Communist China sentiment which was kindled by a series of political confrontations between the Chinese Government, the Hong Kong Government and local Chinese during the transition of Hong Kong from a British colony to a Special Administrative Region (SAR) Government under the sovereignty of China. Growing up in this turbulent transitional period, the young generation of Hong Kong has been socialised to be alienated to the Chinese Government. To study this process, we conducted a case study of a secondary school (including interviews with the teachers and students), a society-wide survey of secondary school students, and a mail questionnaire survey of sampled school teachers in 1988 and obtained four data sets.
On the basis of analysing these four data sets, we found that there was a benevolent image of the Hong Kong Government but a malevolent image of the Chinese Government, However, the event effect on the socialisation of alienation was only salient in a subsample, which thought the most important contrast between Hong Kong and China was the market system, but not visible in three other subsamples. There were hints that students might be socialised to be alienated by parents and stereotyping. Because of the depoliticisation and trivialisation of civic education in secondary schools, we found that secondary school students were not implanted with any political identity. Interestingly, in the "market system" subsample, more civic education helped to heighten the alienation from the Chinese Government. We found also that a prestige school environment, a secondary education, and the school subject "Government and Public Affairs", are three salient factors in producing political alienation. From the eight strata of our sample, we found that the most alienated group of students were Form 7 arts students from symmetrical schools.
The widespread alienation from the Chinese Government was found to be related to students' pessimistic view of Hong Kong's future, an atrophying sense of political community (more opted for migration and took an apathetic attitude towards future political participation), and a rising sense of localism (more identified with Hong Kong and rejected Chinese officials taking up positions in both the public and private sectors of Hong Kong). After the June 4th 1989 Incident, this widespread alienation must be fuelled to the extent that the legitimacy of the SAR government and the political identity of the younger generation of Hong Kong would be in doubt.
Vol 129 parts 1-2, pp. 83-84 [1996] |
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Doctoral Thesis Abstract: Reproductive Biology in relation to phylogeny of the Orchidaceae, especially the tribe Diurideae
Mark Alwin Clements
Aspects of the biology of representatives of the so-called "primitive" members of the family Orchidaceae, especially the fundamentally Diurideae (subfamily Orchidoideae), were studied to determine and characterise developmental patterns and to enunciate phylogenetic relationships between these taxa. Representatives of the closely related families Alstoemeriaceae, Asphodelaceae, Burmannia Haemodoraceae, Hypoxidaceae and Iridaceae were also studied for comparative purposes. Early reproductive tissue development was studied in c. 360 species using freshly collected material of anthers or ovaries, cleared in lacto-phenol and examined either on a Nikon Opiphot-pol or Confocal scanning laser microscope. Images were captured and stored digitally on disc. When fresh material was unavailable, ovaries sampled from dried herbarium specimens and reconstituted in ammonia solution or lacto-phenol, provided sufficient detail to determine general embryological developmental patterns.
Microsporogenesis and microgametogenesis are very uniform throughout most "primitive" orchids and conform to that reported for most other monocotyledons. Microspores mature in tetrads with the exception of Apostasia, Neuwiedia (subfamily Apostasioideae) and certain members of the subfamily Cypripedioideae which form monads. The microspore monads so formed are relatively uniform in shape whereas those that result from the later breakdown of a mature tetrad are irregular in shape.
For the majority of study taxa including all taxa studied in the tribe Diurideae, megasporogenesis and megagametogenesis are characterised as being anatropous, tenuinucellate, with monosporic megaspores that generate Polygonum-type embryo sacs with a bitegmic condition. In the case of Apostasia, Neuwiedia and members of the Cypripedioideae, megasporogenesis is the bisporic type and megagametogenesis results in an Allium-type embryo sac. The unitegmic condition was only found in Epipogium and Spiculaea.
Embryogenesis in the "primitive" orchids, conforms to recognisable developmental patterns characterised by the presence or absence of a suspensor, position (internal or external to the embryo sac), its structure (number of cells, whether in a linear row or as a multiple group of cells) and the origin of cells in the embryo proper (apical cell or apical and basal). Endosperm development was not observed in any orchids. When present, the suspensor appears to aid in the transfer of nutrients from cells of the outer integument which becomes vacuolated as the enbryo reaches maturity. Lipids and other storage bodies were observed in cells of the embryo proper from an early stage of proembryo development. Apomixix and polyembryony were observed in some taxa.
Seven fundamental embryo patterns were identified within the "primitive" orchids, termed the Cyripedioid, Vanilloid, Epidendroid, Cymbidioid, Nettioid, Spiranthoid and Orchidoid embryo patterns. The Cyripedioid pattern is present in Apostasia, Neuwiedia, Paphiopedium, Cypripedium, Phragmipedium, Tropidia, Epipactis, Cephalanthera and Gastodia. The Vanilloid pattern occurs in Vanilla, Eriaxis and Erythrorchis. The Epidendroid occurs in Cattleya and Encyclia. The Cymbidioid pattern exists in Bletilla, Cymbidium, Dipodium, Eulophia and Grammatophyllum. The Neottioid pattern is restricted to Neottia and Listera. Three embryo types exist within the Orchideae, Diurid and Townsonia types, these being differentiated by the number of cells present in the suspensor: four to eight in the Orchideae; one or occasionally two in the Diurids and none in the Townsonia. The Orchideae type is present in both the tribes Diseae and Orchideae. The Diurid type embryo is present in the majority of genera traditionally treated as part of the tribe Diurideae, except for Chloraea, Bipinnula, Geoblasta and Gavilea and the Pterostylidinae which have a Spiranthoid embryo pattern. The Townsonia type is found exc1usively in that genus. The Spiranthoid embryo pattern also occurs in the tribes Spiranthinae and Goodyerinae.
Embryogenesis in Orchidaceae differs from that found in Burmannia, Hypoxis, Alstroemeria and Tribonanthes, mainly by the lack of endosperm and possession of vascularisation in the funiculus.
The ontogeny of the protocorm-seedlings was studied in approximately 260 species, representative of most major taxonomic groups within the Orchidaceae. Eleven basic categories were identified and named, based on gross morphological features, viz. obovoid, obovoid-deorsum, elongate, reptant, discoid, bracteate, rhizomatous, callus, isobilateral, echinate and globular.
Broad (family) and narrow (subfamily and below) based cladistic analyses were undertaken to determine phylogenetic relationships between these taxa. Characters and states were based on studies of the floral and vegetative morphology of fresh material, developmental embryological data and protocorm-seedling morphology. The inclusion of developmental embryological data proved significant in resolving the phylogenetic relationships.
At the broad level, the Orchidaceae, with Apostasia, Neuwiedia and the Cypripedioideae included, is unequivocally shown to be monophyletic based on possession of five synapomorphies; (i) partially or fully fused style and filaments to form a column; (ii) lacking an endosperm; (iii) an undifferentiated embryo; (iv) a protocorm; and (v) 1acking vascularisation of the funiculus.
At the narrow level, subfamily Orchidoideae is monophyletic when the Spiranthinae, Goodyerinae and Pachyplectroninae are included along with the Orchideae (Orchideae, Diseae), Diurid (Diuridinae, Acanthinae and Caladeniinae) and Cryptostylid (Cryptostylidinae, Rimacola, Megastylis) clades. Thus the subfamily Spiranthoideae is taxonomically superfluous. The Diurideae is monophyletic with the remova1 of the Pterostylidinae and the Chloraeinae (to the Spiranthoid clade) and Rimacola and Megastylis to the Cryptostylid clade. a new classification of the subfamily is proposed based on these results.
The Cypripedoid embryo pattern is common to all basic taxa and it is therefore considered the plesiomorphous state for this character. The rhizomatous type protocorm-seedling development is also considered the likely plesiomorphous state for the family. The interpretation of this character and number of fertile anthers in the orchid flower, is re-evaluated based on the results of these cladistic analyses.
Vol 129 parts 1-2, p. 85-86 [1996] |
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Doctoral Thesis Abstract: A contrastive analysis of English and Persian intonation patterns
A. Majid Hayati
The contrastive analysis (Ca) hypothesis attempts to predict the areas of difficulty which learners of a second/foreign language will encounter, It has been the subject of debate among linguists for a long time.
The arguments advanced by the researchers in the field have produced three different versions of the CA hypothesis: strong, weak and moderate. All assume the importance of interference phenomenon but each approaches it from a different viewpoint. however, in all versions, there seems to be argument on two important aspects of the CA hypothesis:
a. degree of similarity corresponds to degree of simplicity
b. degree of difference corresponds to degree difficulty
In the context of this hypothesis, the present study has compared and contrasted the intonation patterns of English and Persian. This research has two primary objectives:
a. As far as I am aware, there has been no comprehensive comparative study of English and Persian intonation patterns, particularly with the aim of identifying possible pedagogical implications. Consequently, the first objective is to present to Iranian teachers of English a set of general ideas about the possible problems that Persian learners of English may face in the process of language learning. The present contrastive analysis will, I hope, be beneficial to language teachers, curriculum designers, and material developers to use in their class activities and overall plans.
b. The second objective is to evaluate and reformulate the hypothesis. To this end, an experiment involving ten Iranian students studying at the University of Wollongong was conducted. The subjects were of approximately the same level of proficiency as determined by the scores they had achieved at the end of a three-month English course.
Approximately sixty out of-of-context sentences of diffcrent types were given to the subjects to read. Their readings were recorded by a high-quality tape-recorder. These were then presented to three native speakers of Australian English (two linguists and a postgraduate student majoring in English Literature) who were asked to describe the intonation patterns. An American native speaker ( a linguist) was asked to read the same sentences and then his reading was used as a model to measure the rise and fall of the intonation. Analysis of the data revealed that although the sentence-final intonation patterns are similar, the subjects nevertheless had problems using the correct English intonation over the whole structure because they attempted to put the primary stress on words partly according to the stress system of their own language. In fact they made very few mistakes in producing the correct sentence-final intonation pattern of English.
The experiment showed the need to take stress patterns into account since they are an integral and significant feature in determining the rise and fall of the pitch contours. Since the stress placement system is different in English and Persian, the intonation pattern of the two languages will also be different. This is illustrated by the following examples from English and Persian:
Persian:
maen ne-mi-tun-aem be-raem?unja.
/Sub Neg-Vpr-can-pp Vpr-go Adv/
English:
I can't go there.
(Abbreviations used in the Persian sentence are as follows: Sub=subject, Neg=negative marker, Vpr=verb prefix, pp=personal pronoun, Adv.=adverb.)
If we only consider the sentence-final position, where the final intonation change occurs, that aspect of the hypothesis that similarities present no difficulties to the learners is supported because the sentence-final intonation patterns of the two languages are quite similar (falling in statements and wh-questions, rising in yes/no questions, etc.)
A look at the above examples reveals that in the Persian sentence, the negative marker, "ne", receives the primary stress and causes a rising tone on the same constituent; but, it is different in English: the change of tone normally close to the end of the sentence where "go" as the content word carries the strongest stress.
Comparing the results of the experiment with the predictions, it was concluded that three out of the four predictions were in fact confirmed. Moreover, that part of the hypothesis suggesting the relation between difference and difficulty was partially (at most in negative sentences) confirmed. In regard to wh-questions, however, the results did not match the predictions. This suggests that in contrastive analyses of the intonation pattern of any two languages it is important that the analyst consider the entire sentence as the domain of the intonation contour. Secondly, since some predictions were not confirmed, a reformulation of the contrastive analysis hypothesis which required consideration of levels of similarity and difference was suggested.
Finally, the study reveals the need to take both similarities and differences into account in treating students' problems in using English intonation, for intonation is a suprasegmenta1 phenomenon and requires that the learner have sufficient command of the elements affecting the tone variations.
This is not, however, best acquired from formal explanations of the nature of intonation of the two languages. Instead, depending on the student's level of proficiency, the whole process of teaching intonation may start with pure imitation of a model (preferably a native speaker's voice on a tape- recorder) and end with free communication. ln the meantime, using gestures to show the rise and/or fall of voice can be of great benefit to teachers of English.
The study provides a more adequate basis for teaching intonation patterns and identifies one source of interference from another phonological process (stress placement) which at the first glance might appear to be not directly related to intonation.
Vol 129 parts 3-4, pp. 149-150 [1996] |
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European impact on Lake Sedimentation in Upland Eastern Australia: Case Studies from the New England Tablelands of New South Wales
Robert J. Haworth
Analysis and dating of sediments from three lake basins set in typical farming country of upland northern New South Wales revealed dramatic environmental changes triggered by the 19th century changeover from Aboriginal to European land use.
European settlement set off processes in each lake catchment that led to a relatively short period of massive sedimentation, followed by a return to low mineral sedimentation rates.
The sedimentation plugs from all three lakes were characterised in the core dating profiles by an unexpected inversion of the exponential decline of the isotope Lead-210 (Figure 1).
This is interpreted as indicating rapid deposition, following extreme catchment erosion, of subsurficial material deficient in Lead-210. Lead-210 is an atmospherically-derived isotope, which has a half-life of only 22.6 years, and therefore a measurable life in soil and sediment profiles of less than 200 years.
The uncharacteristic blip in the Lead-210 profiles marking subsoil deposition demonstrated the use of the isotope as both a sediment ncer and a dating device.
Both functions were tested and correlated with a suite of other forms of sediment analysis, including mineral magnetic measurements, loss on ignition determinations and changes in the frequency of native and exotic pollens.
Another consequence of settlement was greatly increased inputs to the lakes of those chemicals most associated with industrial-based agriculture, lead and phosphorus. The combined effect of siltation and nutrient enhancement boosted the primary productivity of the lakes and transformed largely open water bodies to reed-choked swamps.
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| Figure 1. The marked crosses show the excess Lead-210 profile of a representative lake core, with a mid-core break in the expected downcore decline of excess Lead-210. | Figure 2. The minerogenic sedimentation rate based on the dating profile (CRS model). Note the general similarity between the pre-European and post disturbance sedimentation rates, and the overwhelming dominance of immediate postsettlement (~1840-1860) sedimentation. (Diagrams by S.J. Gale). |
Despite a higher than expected pre-European sedimentation rate from at least one site (Figure 2), the impact of European settlement was enormous, with over half the quantity of post-contact sediment being washed into the basins in less than 25 years. The rapid movement of the material to the lake basins appears to have depleted all readily available sediment sources in the catchments. The lower sedimentation rates that followed the initial infill seem to be more a reflection of this depletion than any particular land use practice or climatic pattern.
The preferred explanation for the change to lower sedimentation rates after the periods of post-contact disturbance is that deposition in the lakes moved from a process-controlled regime. Despite extensive changes in land use and settlement pattern pattern in the last 100 years, as well as some climatic variation, the rate of supply of sediment to the lakes appears to be controlled mainly by the rate at which fresh regolith becomes available on the catchment slopes. Mobilisation of fresh material is more likely to result from poorly managed engineering works than the local farming practice of grazing and small crop rotation.
Vol 129 parts 3-4, pp. 151-152 [1996] |
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Geometry and Structural Evolution of the Leichhardt River Fault Trough, Mount Isa terrain, Australia.
Mark G. O'Dea
The Leichhardt River Fault Trough of the Mount Isa terrain comprises middle Proterozoic sediments, bimodal volcanic rocks and plutons that record processes of intracontinental rifting followed by crustal shortening and metamorphism. It displays superb examples of rift basin development, basin inversion and strike-slip faulting, and offers an opportunity to examine the superposition of extensional and compressional geometries within a spectacularly exposed stratigraphic sequence. This thesis documents the rifting history and resultant rift-basin geometries of the Leichhardt River Fault Trough and incorporates this rifting history in the interpretation of local and regional geometries.
Between ca. 1800 and 1600 Ma, igneous and sedimentary rocks were formed and deposited during at least four episodes of superimposed rifting and associated post-rift subsidence. This protracted extensional history resulted in a succession of stacked intraplate rift basins in which strata of Cover Sequences 2, 3 and 4 accumulated.
Strata ranging from the Mount Guide Quartzite to Lena Quartzite (lower Cover Sequence 2) were deposited and extruded within the N-S oriented Leichhardt Rift, during a period of regional E-W extension. Thereafter, a period of N-S extension resulted in the development of N-tilted half-graben comprising syn-rift strata ranging from the Pickwick Metabasalt to the Whitworth Quartzite (upper Cover Sequence 2). The Lochness Formation and Quilalar Formation were deposited during a period of regional post-rift subsidence.
Deposition of the Quilalar Formation was terminated by a period of E-W extension, footwall uplift and erosion, resulting in the development of the Bigie Unconformity. This unconformity was overlain at approximately 1709 Ma by the syn-rift Bigie Formation and Fiery Creek Volcanics (Cover Sequence 3). A subsequent period of E-W extension, footwall uplift and erosion resulted in the complete bevelling of Cover Sequences 2 and 3 and the development of the Surprise Creek Unconformity. This erosional surface was overlain by rift-related sheet sands of the Surprise Creek Formation, and dolomitic sag-phase sediments of the Mount Isa Group (Cover Sequence 4). Reconstructed stratal geometries are asymmetric in cross-section, indicating that rocks of Cover Sequences 3 and 4 accumulated on the hangingwalls of large E-dipping tilt blocks. Following the deposition of Cover Sequence 4, a subsequent N-S extension event resulted in the development of numerous E-W trending synclines in the hangingwalls of E-W striking normal faults.
Crustal extension was interrupted prior to the formation of oceanic crust by the compressional Isan Orogeny (ca. 1590 to 1500 Ma). The inherited extensional fault architecture and the depositional geometry of rift-sag sequences strongly influenced the structural patterns during shortening. Within the Crystal Creek Block, buttressing against rigid footwall blocks of pre-existing rift faults led to the inversion of an underlying half-graben and the amplification of a pre-existing E-W trepding syncline. E-W trending folds in the June Hill Block and Horse's Head Block also formed as the result of drag against normal faults during rifting and/or as the result of buckling against competent blocks during basin inversion.
In contrast to the Crystal Creek Block, the Lake Julius Syncline may have formed as a rotational strike-slip "popout" during the waning stages of the Isan Orogeny. Reverse faulting occurred as a bend in the Lake Julius strike-slip fault system was removed, causing an originally N-S (?) trending syncline to be rotated counterclockwise over a distance of several kilometres, towards a WNW-ESE orientation. In comparing results from the Lake Julius Syncline with those within the Crystal Creek Block, it is apparent that structures of similar orientation and style may have radically different origins and regional significance.
Solutions to some of the most perplexing geometrical problems in the Leichhardt River Fault Trough can be found through an understanding of the original rift basin geometry. Other solutions require an appreciation of the interaction between this rift basin geometry and regional shortening. Recognising the interaction between extensional fault architecture, stratigraphic geometry and regional shortening is critical to interpreting the structural evolution of the Leichhardt River Fault Trough and the Mount Isa terrain.
Vol 129 parts 3-4, p. [1996] |
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The Effects of Chronic Cerebral Hypoperfusion in the Rat
Lali H.S. Sekhon
It is the aim of this thesis to examine the effects of chronic cerebral hypoperfusion on brain parenchyma in the rat. This objective would be of great clinical relevance since currently to date no systematic studies have evaluated chronic cerebral hyoperfusion. A rat arteriovenous fistula model was utilised which effectively reduced global cerebral blood flow (CBF) by 25-50% in the absence of cerebral infarction, maintained for twenty-six weeks.
Part One of this thesis is concerned primarily with a review of the literature relating to arteriovenous malformations (AVMs), with particular emphasis on the studies of cerebrovascular steal and animal models of AVMs. Subsequent to this, select comments have been made concerning cerebral ischaemia, both acute and chronic.
Part Two presents studies on the pathological effects of the chronic cerebral hypoperfusion in the rat. Initially, the changes occurring as a result of the systemic haemodynamic alterations am examined, followed by a formal evaluation of changes in neural tissue structure that may have occurred as a result of the chronic cerebral hypoperfusion. An initial light microscope survey was followed by transmission electron microscopic studies.
Part Tree evaluates alterations in neuronal function that occur as a result of chronic cerebral hypoperfusion and explores some of the mechanisms involved using electrophysiological in vitro hippocampal slice experiments.
Finally, Part Four of the thesis has attempted to draw together the structural and functional in vitro studies to look for changes in whole animal in vitro behavioural functioning, with an array of behavioural experiments presented.
The conclusions made in Part Five are that subtle structural, electrophysiological and behavioural changes are induced in the rat undergoing 26 weeks of chronic cerebral hypoperfusion. This has not been previously described, with reductions in C13F of this magnitude thought previously to have no effect on the brain.
This thesis represents the first formal experimental assessment of chronic cerebral hypoperfusion. The downfalls of previous studies and strengths of this survey have been discussed. A portfolio of varied experimental approaches have provided a mosaic of the changes in apparently 'normal' brain that occur as a result of chronic cerebral hypoperfusion, and have suggested that established opinions on the thresholds of cerebral ischaemia in the chronic state need modification. A new subtype of chronic cerebral ischaemia has been postulated to exist and is described. Typical of any initial survey of this magnitude, dealing with areas that were previously ill-described, many controversial conclusions have been drawn and many questions have been raised. The mechanisms responsible for the changes are not known. Precise quantification of the pathological changes is yet to be done. The effects of revascularization are also unknown. It is hoped that this thesis stimulates ongoning interest and further work into the areas of chronic ischaen-tia and AVM-induced hypoperfusion, so that these aW other questions may be answered in the not too distant future.
Vol 129 parts 3-4, p. 154 [1996] |
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Situating Style: an Ethnoarchaeological Study of Social and Material Context in an Australian Aboriginal Artistic System
Claire Smith
This is an ethnoarchaeological study of style in the visual arts of Aboriginal people living in the Baninga region of the Northern Territory, Australia. The main concern is the development of a practical framework for the analysis of style in indigenous visual arts. This framework integrates the notions of style, semiotics and social strategy in an attempt to deal with the dynamics of image creation and perception.
The principal result is that the morphological characteristics of style are influenced systematically by the historically situated positions of both producer and interpreter, and by the differing strengths, possibilities and constraints of different raw materials. Moreover, each raw material has inherent qualities that make it particularly suitable for specific social uses. Since different media within an artistic system are likely to exhibit a unique combination of stylisitic characteristics, including differing degrees of diversity, it is incorrect to assume that a single art form will be indicative of an artistic system as a whole.
Research needs to be focussed clearly on the contexts in which archaeological art occurs, and comparative studies need to compare like with like. Single explanations are unlikely to be sufficient since it is most likely that they tell only part of the story. In addition, seemingly anomalous evidence should not be discounted, but should be used as a basis for enquiry into the likelihood of alternative scenarios that co-exist with the main explanation.
Vol 130 parts 1-2, p. 35 [1997] |
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The effect of tenure on range management : a comparison of perpetual and pastoral leases in north-east South Australia
Michael Brett
Abstract of a Thesis Submitted for the Degree of Master of Science at The University of Adelaide
South Australia has long had perpetual and pastoral leases, used for grazing sheep on arid native pastures, lying side by side. This works undertakes a thoroughly structured data collection and analysis to determine to what degree the nature of each leasing system has influenced vegetation resources in the Lower North East.
An initial study investigated the nature of grazing effects on vegetation patterns in three locations widely separated along the tenure division. Influence analysis showed that the small-scale variation of the vegetation was appreciable, an observation which enabled the design of a regional study.
The broad-scale investigation formed the greater part of this work. It detailed the leasing histories of six pastoral and six perpetual lease runs, and explored the degree to which cross-tenure vegetation differences were dependent on them. A multiple regression technique was used so that the influence of many environmental and managerial factors could be taken into account.
This research found that the perpetual leases were more degraded than the pastoral. Although the difference in range condition was small, it was significant and involved the most dominant perennial species (such as Maireana edifolia and Atriplex vesicaira) as well as important features such as the cover of scald and total bush.
The cross-tenure vegetation differences were most strongly and most often correlated with the discontinuity of lease ownership. The highly significant differences in ownership discontinuity between tenure types was concluded to result from differential management attitudes engendered by each type. It was argued that such attitudes stemmed from the disparity between tenures in controls on the intensity of resource use. The difference between perpetual and pastoral terms was seen to have little effect on management.
On the basis of these results, the recent changes to the pastoral tenure system and the Soil Conservation Act must be seen to be encouraging, if properly implemented. However, the inequities which remain between the tenure systems are predicted to continue to cause the rate of degradation on perpetual leases to be greater than that on pastoral.
[Note that legislative changes since 1991 are outside the scope of this thesis].
Vol 130 parts 1-2, pp. 37-38[1997] |
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The ecology of cereal rust mite Abacarus hystrix (nalepa) in irrigated perennial dairy pastures in South Australia
W.E. Frost
Abstract of a Thesis Submitted for the Degree of Doctor of Philosophy at The University of Adelaide
The cereal rust mite Abacarus hystrix (Acari: Eriophyidae), vector of ryegrass mosaic virus in temperate perennial pastures, was initially recorded in Australia in 1989. In South Australia, the mites were found to be common in irrigated perennial pastures in the South Mt Lofty Ranges and Lower Murray Valley, and in dry land pastures of the Fleurieu Peninsula. A. hystrix was numerically dominant in mixed populations with mites of the genera Aculodes and Aceria.
Examination of herbaria specimens of Lolium spp. indicated that A. hystrix was present in the South Mt Lofty Ranges in 1972, and in Victoria in 1982. The mites may have been introduced into Australia in the late 1960's. Study of the seasonal dynamics of A. hystrix populations in South Australian irrigated perennial dairy pastures indicated that numbers were highest in summer and early autumn. The intensity and frequency of grazing had strong influence on the regulation of eriophyid populations. Hard strip grazing of pastures at infrequent intervals retarded the recovery of mite populations more than frequent, lax grazing rotations. The rate of recovery of mite populations following grazing was determined by the size of the residual population, and shifts in leaf age-structure and quality induced by defoliation.
In a glasshouse pot trial, infection of perennial ryegrass by the endophyte Acremonium lolii did not affect the rate of A. hystrix population development or the rate pf movement of mites between plants, although the expression of RMV leaf symptoms was reduced.
There was a degree of population stratification vertically through pastures, with a greater proportion of pre-reproductive adults and deutonymphs occurring closest to the base of the sward. High summer temperatures may decrease mite numbers in heavily grazed swards. In a field experiment, the rate of mite population development was correlated with the recovery of perennial ryegrass following defoliation. Population development was significantly reduced after exposure to temperatures >89°C and >44°C in plots mown to 5 and 10 cm stubble height, respectively.
Temperatures of 29°C, but not changes in photoperiod, were found to accelerate the rate of wax production in A. hyatrix. Possible functions of wax filaments in drag maximization and water conservation were investigated. 'Waxy' mites were found to have lower rates of desiccation-induced mortality, and increased total drag relative to cuticular surface area. The increased non-cuticular surface area associated with the development of wax filaments may increase wind shear stress on mites within the wind velocity gradient at the leaf margin, enhance air-borne buoyancy and prolong the duration of air-borne survival during migration. Polyphenically-derived wax production in A. hystrix should, consequently, enhance the fitness of 'waxy' individuals migrating under summer conditions. Large populations of Aceria were recorded in Australian wheat crops in 1993. There is evidence that two forms of Aceria may commonly occur on wheat in Australia. Perennial pastures and volunteer grasses may act as important over-summer refuge areas for the mites.
Higher numbers of mites did not result in a greater incidence of infection by RMV in study pastures. Control of mite populations in established pastures, in particular, is unlikely to decrease production losses due to RMV infection.
Vol 130 parts 1-2, pp. 39-40 [1997] |
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Negotiating dietary knowledge inside and outside laboratories: the cholesterol controversy
Karin Garrety
Abstract of a Thesis submitted for the Degree of Doctor of Philosophy at the University of New South Wales, Sydney
For more than forty years, doctors and scientists have disagreed about the extent to which dietary saturated fat and high serum cholesterol levels contribute to the development of coronary heart disease (CHD), and whether or not the disease can be prevented by dietary change. Although large amounts of time, effort and money have been devoted to research, experiments have often yielded inconclusive and contradictory results.
This thesis analyses the development of knowledge and policies relating to dietary fat, cholesterol and CHD. It takes a symmetrical stance towards the knowledge claims under investigation. That is, it does not try to ascertain which particular version of the facts is true, or to argue for or against the efficacy of dietary change. Instead it seeks to explicate the social context in which medical science and dietary policies developed. The central problem addressed by the study may be summed up as follows: How and why, in the midst of so much scientific uneertainty, did so many people come to believe that dietary change could prevent heart disease?
The study takes a historical perspective. It draws upon archival material from a variety of sources, including scientific articles, food advertisements, business journals, policy documents, newspapers, popular magazines and the internet. These sources indicate that the development of knowledge and policy relating to diet and CHD was a complex interactive process which cannot be divorced from the cultural, political and commercial contexts in which it occurred.
The putative links between diet and CHD were first popularised by entrepreneurial scientists in the aff1uent society of 1950s America, at a time when the 'facts' were meagre and tentative. These scientists were motivated by therapeutic activism, a drive to 'do something' despite incomplete knowledge. Advice to lower fat consumption struck a receptive chord among sectors of the lay public. Their interest in polyunsaturated fat and cholesterol was further stimulated by commercial interests, which used the new claims to sell products. Cholesterol-lowering diets soon became popular.
The first cautious endorsement of dietary change by an official medical organisation (the American Heart Association) appeared in 1960. It was provisional, subject to the attainment of the definitive proof. However, the changing social circumstances of the United States during subsequent decades favoured the retention and enhancement of policies advocating reductions in fat and cholesterol intakes. As scientists strove to provide proof, food activists, health policy-makers and advocates of 'healthy lifestyles' adopted and promoted dietary change as a progressive cause. It provided a means of resisting the undesirable side-effects of affluence. Dietary self-denial and exercise, as preached by Nathan Pritikin and others, promised physical and almost spiritual renewal and salvation.
There were only two groups of people who questioned the wisdom of the dietary recommendations - scientists who insisted that policies be based on unequivocal evidence of efficacy, and those sectors of the food industry whose profits depended on the sale of products containing saturated fats and cholesterol. During the 1970s, these industries mounted a number of campaigns whieh highlighted the unstable and uncertain aspects of the scientific knowledge linking their products to disease.
Although they were able to recruit sceptical scientists as allies, their challenges were unsuccessful. They could not muster suffcient authority to overturn the claims of the many prestigious medical organisations which supported dietary change. Indeed, the sceptical scientists lost legitimacy because of their alliances with industry. Although the definitive proof remained elusive, policy statements in favour of dietary change accumulated. The scientific, government and medical organisations that issued these statements found it difficult to turn back. In the early 1980s, several large, expensive trials designed to test the effects of cholesterol-lowering regimes produced equivocal results. Scientists shaped these results into endorsements for dietary change and intensified their policies. A diverse range of people had already decided that dietary change was desirable and the scientific results were shaped to reinforce the policies which preceded them.
The study draws on a range of theoretical perspectives within the sociologies of science and medicine. The overall approach is constructivist in nature and makes use of actor-network theory, symbolic interactionism, the ideas of Michel Foucault, and recent work on lay understanding of scientific knowledge.
Vol 130 parts 1-2, pp. 41-42 [1997] |
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Expressions of Inner Freedom. An Experimental Study of the Scattering and Fusion of Nuclei at Energies Spanning the Coulomb Barrier
H. Timmers
Abstract of a Thesis Submitted for the Degree of Doctor of Philosophy at The Australian National University, Canberra, June 1996
This study investigates the fusion and scattering of nuclei at energies spanning the Coulomb barrier. The coupling of the relative motion of the nuclei to internal degrees of freedom can be thought to give rise to a distribution of potential barriers.
Two new methods to extract representations of these potential barrier distributions are suggested using the eigen-channel model. The new techniques are based on measurements of quasi-elastic and elastic backscattering excitation functions, from which the representations are extracted by differentiation. A third method utilizing transfer excitation functions is introduced using qualitative arguments. The techniques are investigated experimentally for the reactions 160+92Zr, 144,154Sm, 186W and 208Pb. The results are compared with barrier distribution representations obtained from fusion data. The methods are further explored using the systems 40Ca+90,96Zr and 32S+208Pb, for which scattering and fusion excitation functions have been measured. The new barrier distribution representations are consistent with the ones from fusion. They are direct evidence of the effects of the internal degrees of freedom on channels other than the fusion channel.
The new representations are, however, less sensitive to the barrier distribution compared to their fusion counterpart. This observation is investigated using coupled- channels calculations. They suggest that residual weak reaction channels, which are not included in the coupling matrix, are responsible for the reduction in sensitivity. In the case of quasi-elastic scattering a distortion of the barrier structure above the average barrier is observed. This effect appears to be due to the de-phasing of the scattering amplitudes contributing to each eigen-channel. Using the heaviest system, 32S + 208Pb, it is demonstrated that there is no improvement in sensitivity to the barrier distribution for systems with large Sommerfeld parameters. This suggests that diffraction effects are not likely to be the cause of the sensitivity reduction.
The new techniques may be employed successfully in systems with pronounced barrier structure below the average barrier. This is the case for the reactions 40Ca + 90,96Zr. It is shown that for these systems the quasi-elastic seattering and the fusion representations of the barrier distribution contain the same information. The extracted barrier distributions for the two reactions are completely different. They are compared to assess the relative importance of collective excitations and neutron transfer in fusion. Exact coupled-channels calculations show that the distribution for 40Ca+90Zr arises from the coupling of the relative motion to double phonon excitations of 90Zr. Further calculations suggest that the reaction 40Ca+ 96Zr involves additional coupling to sequential neutron transfer, which is proposed to be a precursor of neutron-neck formation. Double phonon excitations are also seen to be important in the system 32S+ 208Pb, for which the barrier distribution representations show in addition signatures of one and two neutron transfer.
Vol 130 parts 3-4, p. 109 [1997] |
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THE FEASIBILITY OF USING MOLE DRAINAGE TO CONTROL WATERLOGGING IN IRRIGATED AGRICULTURE
E.W. CHRISTEN
Abstract of a Thesis Submitted for the Degree of Doctor of Philosophy at Cranfield University, England September 1994.
The Murrumbidgee Irrigation Area (MIA) in New South Wales has extensive shallow watertables, < 2m deep, and poorly structured heavy clay soils, leading to soil waterlogging and salinisation. This study investigated the feasibility of using mole drainage to control waterlogging in irrigated agriculture. The standard moling technique used in the United Kingdom in rain fed agriculture was adapted to the flood irrigated conditions of the MIA.
Experiments were carried out on three heavy clay soils, representative of the area and with a range of inherent structural stabilities in water. Preliminary experiments identified mole channel failure mechanisms similar to those already described in the United Kingdom. Having identified these mechanisms steps were taken to improve mole stability.
Two relatively stable soils and one highly swelling\dispersive soil were chosen. Experiments to improve mole stability were carried out under furrow irrigation, flood irrigation of bays and sprinkler irrigation. These experiments consisted of groups of 30-50 moles, each 25-50 m long. Four main experimental sites were monitored for between 6 and 22 months.
In the stable soils the mole failure mechanism was by roof/expander failure. Using a mole plough with smaller geometry than the standard United Kingdom design resulted in acceptably stable mole channels in these soils. The use of an angled mole leg was found to have potential for increasing mole stablhtybutfurther development ofthis equipment is required for reliable mole formation.
In the unstable soil the mole failure mechanism was by unconfined soil swelling. To control this, gypsum was used above the mole channel to improve the inherent soil stability. The use of sulphuric acid and calcium chloride sprayed onto the mole channel walls proved unsuccessful. A mole filler of rice hulls was found to be effective in preventing soil swelling into the mole channel.
For stable mole formation adequate confining stresses and uniformly plastic soil conditions at moling depth were required. Post rice harvest was found to be ideal. Methods of achieving suitable conditions at other periods in the farming calendar were identified.
Mole discharge measurements revealed that water loss through mole drains during irrigations was high. Thus there was a requirement to prevent this water loss whilst still achieving waterlogging control.
To prevent water loss during irrigations attempts weremade tothrottle the connection between the soil surface and mole channel.
These were found to be largely unsuccessful. By blocking the mole channels during irrigation, discharge was prevented and mole condition was not impaired more greatly than allowing moles to discharge freely.
Mole drainage was found to control waterlogging but crop yield increases were only around 10%. To achieve the optimum benefit from mole drainage secondary soil loosening to increase soil porosity is required.
The salinity of mole drain discharge water was measured. This revealed that mole leached salts and that the leaching was more efficient under rainfall or sprinkler irrigation than flood irrigation. The mole, drain discharge water was usually of suitable quality for refuse on farm.
The research showed that there is the potential for using mole drainage to control waterlogging and salinity in irrigated agriculture, at a lower cost than with pipe drains. Methods for incorporating mole drainage into the farming system and landscape of the MIA are proposed.
Vol 130 parts 3-4, p. 111 [1997] |
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DYING IN PRISON: A STUDY OF DEATHS IN CORRECTIONAL CUSTODY IN SOUTH AUSTRALIA 1980-1993
M. J. DAWES
Abstract of a Thesis Submitted for the Degree of Doctor of Philosophy, Flinders University, South Australia 1997.
This thesis examines the 38 deaths by accident, homicide, natural causes and suicide of Aboriginal and white prisoners which occurred in the South Australian prison system from 1 January 1980 to the 31 March 1993. The pattern of deaths in SA is compared with the pattern of deaths found nationally by the Royal Commission Into Aboriginal Deaths in Custody (RCIADIC) and the differences between the SA and national populations are discussed. Other variables which were not included in the RCIADIC are considered in this thesis such as the security rating of the prison, the location of death, time of death, month of the year and season.
A case control study was designed to identify any combinations of personal and social differences between the 37 male prisoners who died and a control group of 195 prisoners matched for gender and date of admission. Most of the studies into deaths in custody fail to compare their findings to a properly constructed control group and so the question remains as to how many of the surviving prisoners exhibited the same characteristics and were exposed to the same environment as those who died. The theoretical grounding for the case control study is that deaths in custody occur because of the interaction between personal factors (those characteristics which the prisoner imports to the prison) and situational factors causing distress which occur while in prison. A review of the literature shows that much of the research work to date has been to search for a statistically based profile of the 'at risk prisoner', but this thesis suggests that attempting to identify vulnerability based on the interaction between personal and situational factors is a more useful approach. The case control study showed that there are statistically significant differences between those who died and the control group in terms of age, place of birth, marital status (with prisoners who were separated or divorced being more likely to die in custody), number of times in custody, time served, seriousness of offence including use of violence, physical trauma, significant illness, psychiatric illness, taking medication while in custody and when security measures were taken to protect, isolate or punish.
An analysis of the coronial verdicts in 36 of the 38 deaths was undertaken to determine the extent to which deprivational factors substantially contributedtothemdlvidua1 deaths.
The findings of the thesis are discussed in the context of the literature and the value of the findings in assisting those who care for prisoners considered. Finally, preventive strategies are discussed and social work interventions which might identify and assist vulnerable prisoners and their families at critical times are considered.
Vol 130 parts 3-4, p. 112 [1997] |
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THE INTERFACE BETWEEN SYNTAX AND DISCOURSE IN KORAFE, A PAPUAN LANGUAGE OF PAPUA NEW GUINEA.
CYNTHIA J.M. FARR
Abstract of a Thesis Submitted for the Degree of Doctor of Philosophy at Cranfield University, England, September 1994.
This dissertation focuses on the structure and function of three types of complex constructions which are central to Korafe discourse: (1) serial verb constructions (SVCs), (2) switch reference constructions (SRCs), and (3) co-ranking constructions or sentences (CRSs).
Each of the complex construction types has as obligatory constituents trio or more clauses or verbs. SM and SRCs are chaining' constructions, which terminate with a verb, more finitely inflected than the preceding verbal constituents i.e. verb stems in SM and medial verb forms in SRCs. Syntactic constraints masked on or implicit in chaining structures enable the speaker to monitor subject reference from verb to verb without using very many overt noun phrases. The order of the verbs in these chains is non-reversible and mirrors the order of the events they represent in the real world. This makes them choice vehicles for conveying the foregrounded storyline in narratives, legends, and procedures. Utilising verbs without their standard arguments to a) represent familiar events (e.g. ghambudo 'dig' for 'dig a hole', jedogovedo 'chop plant for making a garden') and b) mark shifts in venue or temporal seeing (aira buvudo 'he went and arrived', ravara atetiri 'they slept and it [day] dawned') enables the speaker to concentrate on the specifics of the story in question, use noun phrases to highlight dominant and/or prominent participants and props.
In CRSs, all the constituents terminate with verbs of the same rank, namely final verbs, or in topic-comment constructions, predicate complements. CRSs combine clauses, SRCs, and/or other co-ranking sentences by juxtaposing or conjoining them. CRSs supply background information in discourses that primarily present events in iconic order. They are also extensively used in more thematically oriented discourses, such as encyclopaedic descriptions, explanations, and hgrtatory speeches.
SRCs and CRSs may be segmented into information chunks that are thematically unified. These thematic clause chain units (TCCUs) are defined by formal and semantic criteria. They range from one to nine words, comprising up to five clauses in an SRC and averaging between one to four seconds in length. They are uttered as a basically pausefree unit.
Other features of the language relevant to the account of these complex constructions are also described.
Vol 130 parts 3-4, pp. 113-114 [1997] |
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THE EARLY DEVELOPMENT OF CLINICAL DIALYSIS: THE IMPORTANCE OF SYMBOLISM IN SUCCESSFUL SCIENTIFIC ENDEAVOURS
C.R.P. GEORGE
Abstract of Thesis Submitted for the Degree of Master of Science at the University of Sydney
This thesis presents an account of the series of experiments performed into dialysis by Thomas Graham in 1861; by his immediate successors; by Emil Abderhalden and Fritz Pregl; by the Baltimore group of John Jacob Abel and his Collaborators (1913-15); and by others who were more peripherally involved. Its primary purpose is to demonstrate the roles that each of these investigators played in the development of clinical dialysis. Its secondary purpose is to propose a novel theory of success in the scientific endeavour, and to use dialysis as a case study with which to test this.
An account is presented of Graham's experiments, his development of an idea, and his invention of the word dialysis to describe the observations and idea. He recognised that urea - an important uraemic toxin - was dialysable. He established his reputation by a forceful application of observation, conceptualisation, and symbolism to the topics that he investigated.
Several minor figures followed Graham, but were soon forgotten. Then Abderhalden attempted to use dialysis in a test for pregnancy, but based the Abderhalden reaction on false assumptions. His observations and his ideation were flawed. Although he developed a symbolic name for his test, Adid not work. He lapsed into obscurity. Pregl, however, applied dialysis successfully to microanalysis of chemicals. His observations, ideas and symbolism succeeded; he won a Nobel Prize for Chemistry and his procedures entered all modern biochemical laboratories.
Abel was far more complex. His personal laboratory notebooks are held in the Johns Hopkins Hospital archives. A reworking of these is presented and demonstrates that his private aims differed from his public ones. His assistants' intentions also were hardly those of idealistic scientists. His observations were flawed and his ideas confused, but his reputation survived his own misinterpretations because of adulation of his work by a gullible lay and medical press. Perhaps his misinterpretations were fortuitous, but probably they were not. Certainly, they implied clinical applications far beyond those justifiable by the documented records claims which Abel. never really denied, and which his assistant Rowntree, actively encouraged. Driven by the publicity, Abel embarked upon a hopeless - and apparently lethal - experiment on a sick young woman. Uninformed about that disaster, community acceptance - the factor crucial to the judgement of experiments as 'successful'- remained uncritically positive. It idolised Abel. (in truth, a some what hapless scientist) as a brilliant physician and the inventor of the artificial kidney machine. His symbolism survived just long enough to enable his successors to link their more reliable observations and ideas with it, to develop these to clinical fruition, and thereby to secure for Abel his place as an apostle of science.
The secondary purpose of this thesis is to propose a trinitarian theory of scientific success. Observations, ideas, and symbols are three co-existent and necessary components of a successful scientific enterprise. None is sufficient without both of the others. Observations alone are empty. An astute observer can weld observations together into ideas, but unanchored ideas will float away. Society is most likely to judge an observer as a successful contributor to science if that observer creates appropriate symbols (usually unique words or phrases), with which to fix accurate observations and good ideas - to epitomise their meaning to the public.
An interesting application of this theory relates to the public relations implications of unsubstantiated symbolism. Reluctance to admit this can then so readily promote false observational claims and the temptation of scientific fraud.
Whilst a single case study can at best merely support a hypothesis - it will never prove it - the evidence from dialysis dovetails with the present contentions. Hence their validity may be worth testing against other cases.
Vol 130 parts 3-4, pp. 115-116[1997] |
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CHEMICAL RELATIONSHIPS IN WATERS AND SEDIMENTS OF SOME URBAN STREAMS, WITH PARTICULAR REFERENCE TO HEAVY METALS AND PHOSPHORUS
WARWICK J. HAYES
Abstract of Thesis Submitted for the Degree of Doctor of Philosophy University of Technology, Sydney
This thesis describes two studies of the chemistry of freshwater streams in the Sydney basin.
The first was a survey of 86 waterways, sampled under low flow conditions. Samples were generally low in salinity, soft, of poor buffering capacity and dominated by sodium and chloride. Co-dominance by calcium, magnesium and (bi-)carbonate occurred in a number of particular cases. Multivariate analyses indicated three groups, separated primarily by levels of dissolved nutrients, trace metals, turbidity and colour. Groupings were associated strongly with the type of catchment development. Streams in areas relatively unaffected by human influence had notable uniformity in chemistry, while those from developed catchments were varied. Heavy metal contamination was relatively low, although a few of the samples displayed inordinately large levels of one or more metals. In such cases the more extreme measurements of phosphorus and nitrogen were also seen. These findings were consistent with occasional or localised elevation of contaminant levels.
The second study involved monitoring of three Hawkesbury Sandstone streams. Sampling of surface waters, interstitial waters and sediments was performed at irregular intervals over a two year period at three stations within each site. The streams predominantly existed under low flow conditions and showed similar major ion chemistries to the majority of the survey samples. Levels of calcium and total carbonate, plus heavy metals and nutrients were generally higher in the urbanised creeks, compared to the reference stream. During a heavy storm, high levels of nutrients, suspended solids and colour were detected in all surface waters at peak-flow, as well as alkaline pH, oxidising redox, and reduced conductivity, alkalinity and hardness.
The sandy sediments were characterised by very low levels of organic matter and cation exchange capacity. Sequential extractions identified that the sums of secondary phase lead, zinc and copper were over nine, four and two times that of the corresponding residual, respectively. Greatest proportions of zinc and lead were associated with coatings of iron and manganese oxides, or coarse waste particles. Copper was preferentially associated with organic matter. Concentration gradients between interstitial and surface waters were rare and release of sedimentary constituents should occur rapidly from the upper-most particulates.
Poor water and sediment qualities were often observed in the urban sites. Poor water quality was also seen on occasion in the reference stream. However, since poor sediment quality was not detected at those times and interstitial waters for all sites displayed high within-site variability, surface waters were considered the most reliable short-term indicator of condition for Hawkesbury Sandstone streams. Multidimensional scaling showed that all streams had distinct water and sediment chemistries. High levels of temporal and spatial variability were apparent within the urbanised sites particularly in interstitial waters - mostly due to concentrations of heavy metals, phosphorus and suspended solids. Seasonal differences were detected, but only in terms of the level of variability between summer and winter samples.
Vol 130 parts 3-4, pp. 117-118[1997] |
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SOIL ACIDIFICATION IN THE HUNTER VALLEY
J.B. ROBINSON
Abstract of Thesis Submitted for the Degree of Master of Science Charles Stuart University, Wagga Wagga NSW, 1996
Soil acidification due to agriculture is a widespread and significant problem in Australia. Soil acidification from fossil fuel use and deposition of resulting acids onto the landscape may also be important in some areas, but has received little study in Australia. The latter phenomenon is known colloquially as acid rain. This thesis examines these problems in the Hunter Valley, an important agricultural region with two large coal-fired power stations.
Acid deposition from the power stations is estimated from rainwater chemistry and modelled atmospheric SO2 concentrations. Acid production from agriculture is estimated from agricultural land suitability and climatic information. Soils collected from 51 sites are analysed. Four soil classes were defined, dilferentiated by their parent materials; basalt (I), shale, siltstone and felsic igneous rocks (II), sandstone (III), and alluvium (usually basaltic, IV). Surface soils at 7 of the 51 sites are already strongly acidic (pH, 1:5 soil:0.01: MCaCl2, < 4.5), and have high concentrations of exchangeable aluminium (A13+).
pH buffer capacity was measured in all 51 surface soils (0-10 cm), and in 59 samples from various depths between 10 and 100 cm. Soil pH buffer capacity (0-10 cm) between pH 4.5 and pH 6.5 ranged from 7 to 50 mmol H+/kg/pH, and this is highly correlated with organic carbon concentration (OC,%). Buffer capacity (pH 4.5 to 6.5) per unit OC is greater at depth, as expected for more humified organic matter. Weak organic acids are therefore important substances buffering pH in these soils.
The dissolution of basic soil minerals increases soil pH. This was studied by incubating several soils with acid at 600°C to enhance otherwise slow dissolution. Basic non-carbonate minerals dissolved in basaltic soil, and manganese oxides dissolved in all of the soils. Soil pH was also affected during incubation by the oxidation of organic C and mineralisation of organic N.
Soils sensitivity to added acids was calculated from the quantity of acid (kmol H+/ha/year) necessary to reduce the surface pH to a target value (4.5) in 50 years. This indicator is high in classes I and IV, variable but mostly low in II, and very low in class III, where the mean is less than 0.2 kmol H+/ha/ year. The most acid-sensitive soil types (II and III) occur in 366,000 and 168,000 ha of the study area (656,000 ha) respectively.
Agriculture poses a very high risk to approximately 10,000 ha of soil types II and III, and another 156,000 hectares is at a lower risk. Acid deposition also poses a substantial risk to sensitive soils. A small area of type III soils and a large area of type II soils are afficted by high rates ofacid deposition (> 0.4 kmol H*/ha, 3,000 and 91,000 ha, respectively). The exact risk to type II soils is difficult to determine because basic mineral dissolution may buffer the pH in these soils. Better understanding of mineral dissolution in soil types II and III is needed to accurately assess their sensitivity to acids.