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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Recruitment and age dynamics of Anguilla australis and A. reinhardtii glass eels in the estuaries of New South Wales

January 2005 (has links)
Shortfin eels (Anguilla australis) and longfin eels (A. reinhardtii) are true freshwater eels of the genus Anguilla. There are many mysteries still unsolved for the freshwater eel lifecycle, such as location of the spawning grounds, conditions that promote metamorphosis from the leptocephalid to glass eel phase, and the mechanisms that affect glass eel recruitment. In Australia, little is also known about the estuarine habitats of glass eels as they migrate towards freshwater, and the age at which these eels enter estuaries. Both species are of commercial importance in the estuary fishery where they are caught in eel traps for export. There is also a small, but potentially lucrative, aquaculture industry for ongrowing glass eels to market demand size. This thesis investigates the spatial and temporal recruitment of both species of glass eels to estuaries within NSW, the habitats that may be of importance to them as they continue their upstream migration, and the age at which these eels entered the estuaries. Firstly, a new sampling device needed to be developed since conventional methods to catch glass eels often required constant observation of gear, multiple operators, specific physical site characteristics, and/or were expensive. The artificial habitat collectors that were developed were then used to sample six estuaries in NSW monthly within one week of the new moon. Shortfins showed a more consistent and defined recruitment across all sites than longfins, where the peak shortfin recruitment season was from April - August. Longfins recruited primarily from January - May but often recruited outside of this period. Five year collections at one of these sites provided important recruitment information. It appeared that longfins failed to recruit to this site during 2000/01, which could affect commercial catches of this species when they enter the fishery. The East Australian Current (EAC) probably transports glass eels from spawning sites in the Coral Sea southward to the east coast of Australia but there was no predicted lag time in the recruitment of eels from northern to southern estuaries. Therefore, it was not possible to predict the timing of recruitment of glass eels in one estuary based on the timing of recruitment in another more northern estuary. When glass eels enter estuaries their upstream migration is assisted by the night flood tide. During the ebb tide, glass eels burrow into the substrate and resurface at the next night flood tide. The eels do not select particular habitats at this time, rather, their location is dictated by the tide. However, once glass eels reach the estuarine/freshwater interface, they may prefer more complex habitats such as seagrass/macrophytes or rocks/cobbles in which to hide during the day. At this interface, glass eels undergo a physiological change to adapt to a freshwater existence and this change may take up to a few weeks. During this time, glass eels commonly enter the water column during the night flood tide and may be able to locate more suitable habitats in which to hide during the day. The ages of shortfin and longfin glass eels caught in estuaries were examined both spatially and temporally. As the EAC travels north to south, glass eels recruiting to the southern sites were expected to be older. However, shortfins that recruited to the northern-most site in this thesis were older than at all other sites while there was no difference in the ages of longfins. Also, when the ages of longfins that recruited during the main recruitment period were compared to the ages of longfins that recruited outside of this period, there was no difference in ages. Therefore, the hypothesis that these later recruiting eels may have been caught in an eddy prior to their estuarine arrival has been disproved. The ages of shortfins that recruited in two separate years were significantly different from each other and may be due to shortfins' ability to detrain more easily from the weaker currents that exist at these recruitment periods. Conversely, there was no difference in the ages of longfins that recruited in the same month during three separate years. The estimated hatch dates for shortfins was estimated at October to January, while for longfins, estimated hatch time was July to September for eels that recruited during the peak recruitment period. For longfins that recruited outside of the main recruitment period, estimated hatch times were from December to February. It is unknown, however, whether longfins have an extended spawning period, or whether silver eels arrived at the spawning grounds later and thus produced later arriving longfins. Continuous monitoring of glass eel recruitment to estuaries is necessary to determine whether there are long term declines in the recruitment of Australian eels similar to the declines recently observed for eels in Europe and Asia.
12

Geochemical signals in transported regolith in response to deeply buried Cu-Au mineralisation.

Mokhtari, Ahmad Reza, School of Biological, Earth & Environmental Sciences, UNSW January 2007 (has links)
Transported regolith has the capacity to mask underlying mineralisation by restricting the migration of most trace elements to the surface. Oxidation of sulphides generates highly mobile H+ which may migrate to surface, resulting in alteration of minerals and redistribution of elements within transported regolith cover. A detailed geochemical and geophysical study has been conducted at the Mandamah Cu-Au deposit in central-western New South Wales, where sub-economic mineralisation is covered by ~50 m of transported regolith and ~30 m of in situ regolith. A shallow-penetration electromagnetic survey was undertaken on nine transects and detailed mineralogical and selective extraction/ICP-MS geochemical analysis performed on regolith samples obtained from 107 soil cores and 16 pits spanning three extensive traverses across buried mineralisation. The selective extractions used were ammonium acetate, hydroxylamine.HCl and aqua regia. A distinct vertical zonation exists in the upper two metres of the transported regolith cover across the site and is related to soil mineralogy, soil pH, electrical conductivity and the amount of selectively extractable elements using the different geochemical extractions. The upper zone of near-neutral soil pH contains organic material but little carbonate; the intermediate high-pH zone has up to 2% Mg-calcite; the underlying low-pH zone displays Fe mottling. This zonation results from precipitation of salts due to evaporation, changes in redox potentials and accumulation of organic materials, in an otherwise relatively homogeneous quartz-clay alluvium. Ground conductivity measurements and selective extraction geochemistry display a strong response to parts of the underlying mineralisation. The principal signature is the depletion of Ca, S and Na, a reduction in the cation exchange capacity, the presence of non-carbonate alkalinity and a low electrical conductivity. A model to account for these patterns has been developed and involves a "prograde" stage of alteration of clay mineralogy and a redistribution of carbonates and various trace elements due to the development of an "acid chimney" above the oxidizing mineralisation during a period of elevated water tables and a "retrograde" stage involving a redistribution of some mobile elements back into the former acid chimney zone following the onset of more arid conditions. The results of this research demonstrate that the effects of sulphide mineralisation on the upper transported regolith at Mandamah can be detected using a combination of selective extraction geochemistry and shallow depth conductivity measurements. This technique has potential application in similar arid to semi-arid terrains.
13

Rural clinical placements for dental students : an action research study

Cockrell, Deborah Jane January 2005 (has links)
Doctor of Philosophy / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au
14

Communication, transportation and the decentralization of selected public services in New South Wales (Australia)

Langdale, John V January 1973 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1973. / Bibliography: leaves 294-302. / xii, 302 l illus., maps, tables
15

Rural clinical placements for dental students : an action research study

Cockrell, Deborah Jane January 2005 (has links)
Doctor of Philosophy / This work was digitised and made available on open access by the University of Sydney, Faculty of Dentistry and Sydney eScholarship . It may only be used for the purposes of research and study. Where possible, the Faculty will try to notify the author of this work. If you have any inquiries or issues regarding this work being made available please contact the Sydney eScholarship Repository Coordinator - ses@library.usyd.edu.au
16

The electrification of the Sydney energy system, 1881-1986

Wilkenfeld, George January 1989 (has links)
Thesis (PhD)--Macquarie University, Centre for Environmental and Urban Studies, 1989. / Bibliography: leaves 360-379. / Electrification: an historical process -- A prehistory of electrification: the Sydney energy system to1881 -- Slow dawn of the electric light, 1881-1904 -- The momentum of growth, 1904-1932 -- The state takes charge, 1932-1950 -- Triumph of the grid, 1950-1986 -- The limits to electrification. / All technological systems require energy. The concentration of human population and economic activity in cities has relied on the development of urban energy systems, which bring energy to the city and distribute it to points of end use within it. Over the past century, electro-technology has come to dominate urban energy systems throughout the developed world. This process has been imperfectly documented and analysed, because the relationships between electricity and the energy service markets and local political frameworks within which each instance of urban electrificaiton has taken place have generally been neglected. -- This thesis presents electrification as an historical change in the urban energy system. It identifies the most important influences on urban energy demand and on the organisation of energy supply, and traces their interaction before the introduction of electro-technology, then from the beginning of electrification in the 1880s to its completion in the 1980s. -- Urban electrification is best observed and understood by following its course within a single city. Sydney is well suited to such an analysis, since it is highly electrified and encompasses within its two hundred year history all the major energy technologies of the past millenium. During the first century of its existence, it developed distinctively urban markets for transportation, street lighting, commercial, industrial and residential energy services. These were revolutionised by steam and by gas, the first specifically urban energy technology. -- The thesis examines how each energy form in turn gained a foothold in the Sydney energy system, diffused through it and spread beyond it to the rest of the state of New South Wales. It analyses long term trends in each of the various urban energy markets, and draws parallels in the pattern of succession of supply technologies. It demonstrates that these patterns were repeated with the introduction of electricity and, in the 1970s, by its emerging successors. -- During Sydney's second century each of its energy markets was electrified in turn, while its separate electricity supply systems coalesced into a unified grid serving the entire metropolis, and extending later into the rest of the state. Largely as a result of political circumstances in the 1880s, when electric lighting was first introduced, the municipal electricity supply organisations acquired considerable influence and autonomy, and resisted the later attempts of state governments to co-ordinate their development. --The electrification of the Sydney and NSW energy systems had largely run its course by the late 1970s. Electricity supply had exhausted the economies of scale and technological development which had given it an advantage over other fuels. It had saturated the urban energy markets, and was facing new competitors in the form of natural gas and more efficient utilisation technologies. These changes in the energy system exacerbated the inherent problems in the organisation of electricity supply, which was predicated on unlimited growth and slow to adapt to the end of electrification. / Mode of access: World Wide Web. / [13], 379 leaves ill., maps
17

The Sydney entrepreneurs, 1788-1821 : a study in colonial enterprise with particular reference to the career of Simeon Lord /

Hainsworth, D. R. January 1969 (has links) (PDF)
Thesis (Ph.D.)--University of Adelaide, Dept. of History, 1969. / Includes bibliographical references (leaves 384-399).
18

Hepatitis B and C associated cancer and mortality: New South Wales, 1990-2002.

Amin, Janaki, Public Health & Community Medicine, Faculty of Medicine, UNSW January 2006 (has links)
This thesis examines cancer and mortality rates among people diagnosed with hepatitis B (HBV) and C (HCV) infection in New South Wales (NSW) from 1990 through 2002, by linking hepatitis notifications with the NSW Central Cancer Registry (CCR) and National Death Index. Of the 39101 HBV, 75834 HCV and 2604 HBV/HCV co-infection notifications included 1052, 1761 and 85 were linked to cancer notifications and 1233, 4008 and 186 were linked to death notifications respectively. Of 2072 hepatocellular carcinoma (HCC) notifications to the CCR 323, 267 and 85 were linked to HBV, HCV and HBV/HCV co-infection notifications. Incidence of HCC was 6.5, 4.0 and 5.9 per 1000 person years for HBV, HCV and HBV/HCV co-infected groups. Risk of HCC in those diagnosed with hepatitis was 20 to 30 times greater than the standard population. There was a marginally statistically significant increased risk of immunoproliferative malignancies associated with HCV infection (SIR=5.6 95% CI 1.8 ???17.5). Risk of death for those with hepatitis was significantly greater, 1.5 to 5 fold, than the general population with the greatest risk among those with HBV/HCV co-infection. The primary cause of HBV deaths was liver related, particularly HCC, whereas in the HCV groups drug related deaths were most frequent. Among people with HCV, risk of dying from drug related causes was significantly greater than from liver related causes (p=0.012), with the greatest increased risk in females age 15- 24 years (SMR 56.9, 95%CI 39.2???79.9). Median age at diagnosis of HCC varied markedly by country of birth and hepatitis group: HBV 66, 63 and 57years ; HCV 51, 68 and 71 years; unlinked 69, 70 and 64 years for Australian, European, and Asian-born groups, respectively (P<0.0001 for all groups). While the risk of cancer, particularly HCC, is elevated among people with HBV and HCV infection, the absolute risk remains low. Young people with HCV face a higher mortality risk from continued drug use than from liver damage related to their HCV infection. The influence of IDU in the epidemiology of HCC in New South Wales was possibly reflected in the varying distributions of age and country of birth.
19

Death among a cohort of prisoners in New South Wales Australia ??? a data linkage study

Kariminia, Azar, Public Health & Community Medicine, Faculty of Medicine, UNSW January 2007 (has links)
This thesis examines mortality rates among adults who experienced full-time imprisonment in New South Wales between January 1988 and December 2002, by record linkage to the Australian National Death Index. The cohort included 76383 men and 8820 women. Over a mean follow-up of 7.7 years, 5137 deaths (4724 men, 423 women) were identified. Three hundred and three deaths (295 men, eight women) occurred in custody. The median age at death was 36.6 years for men and 32.7 years for women. The prominent causes of death were drug overdose, suicide, accidental and cardiovascular disease. The crude mortality rate was 797 per 100000 person-years for men and 685 per 100000 person-years for women. Risk of mortality was 3.7 times greater in male and 7.8 times greater in female prisoners than the standard population. The excess mortality was substantially raised following release from prison in both men (standardised mortality ratio 4.0 vs 1.7) and women (standardised mortality ratio 8.2 vs 2.1). The period of highest risk of death was the first two weeks after release. Drug overdose was the main cause of death, responsible for 68% of the deaths in the first two weeks for men and for 90% of the deaths in this period for women. In men, there was also a clustering of suicide directly after release. Prisoners admitted to prison psychiatric hospital, repeat offenders and those in the early stage of followup were at increased risk of mortality. Violent offenders were overrepresented in suicide figures and property offenders in death from overdose. Minority groups, in particular men, had a lower risk of death than white people. The above findings reinforce how disadvantaged prisoners are, measured by mortality as the most fundamental scale of human wellbeing. Prison represents a potential opportunity for treatment and public health intervention to address some of the health problems underlying the high mortality found in this study. The key challenge is, however, to provide a continuum of care between the prison and community.
20

Hepatitis B and C associated cancer and mortality: New South Wales, 1990-2002.

Amin, Janaki, Public Health & Community Medicine, Faculty of Medicine, UNSW January 2006 (has links)
This thesis examines cancer and mortality rates among people diagnosed with hepatitis B (HBV) and C (HCV) infection in New South Wales (NSW) from 1990 through 2002, by linking hepatitis notifications with the NSW Central Cancer Registry (CCR) and National Death Index. Of the 39101 HBV, 75834 HCV and 2604 HBV/HCV co-infection notifications included 1052, 1761 and 85 were linked to cancer notifications and 1233, 4008 and 186 were linked to death notifications respectively. Of 2072 hepatocellular carcinoma (HCC) notifications to the CCR 323, 267 and 85 were linked to HBV, HCV and HBV/HCV co-infection notifications. Incidence of HCC was 6.5, 4.0 and 5.9 per 1000 person years for HBV, HCV and HBV/HCV co-infected groups. Risk of HCC in those diagnosed with hepatitis was 20 to 30 times greater than the standard population. There was a marginally statistically significant increased risk of immunoproliferative malignancies associated with HCV infection (SIR=5.6 95% CI 1.8 ???17.5). Risk of death for those with hepatitis was significantly greater, 1.5 to 5 fold, than the general population with the greatest risk among those with HBV/HCV co-infection. The primary cause of HBV deaths was liver related, particularly HCC, whereas in the HCV groups drug related deaths were most frequent. Among people with HCV, risk of dying from drug related causes was significantly greater than from liver related causes (p=0.012), with the greatest increased risk in females age 15- 24 years (SMR 56.9, 95%CI 39.2???79.9). Median age at diagnosis of HCC varied markedly by country of birth and hepatitis group: HBV 66, 63 and 57years ; HCV 51, 68 and 71 years; unlinked 69, 70 and 64 years for Australian, European, and Asian-born groups, respectively (P<0.0001 for all groups). While the risk of cancer, particularly HCC, is elevated among people with HBV and HCV infection, the absolute risk remains low. Young people with HCV face a higher mortality risk from continued drug use than from liver damage related to their HCV infection. The influence of IDU in the epidemiology of HCC in New South Wales was possibly reflected in the varying distributions of age and country of birth.

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