No description available.

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.

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.

University of Chicago, 1898, Thesis (Ph. D.) / Includes bibliographical references (p. iii-xxii). - OCLC, 32164936. - Reproduction of original from Harvard Law School Library

Thesis (Ph. D)--Indiana University, 1987. / Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin-Madison, 1992. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 322-351).

Zugl.: London, University, Diss., 2005. / Hergestellt on demand.

Very little is known about the small firms sector and the new firm formation process in the Welsh economy. This study attempts to bridge this gap in Knowledge and adds to the growing body of information on new firm formation and development in the U.K. and its regions. The approach adopts a largely microeconomic perspective within a business policy strategy. Data is obtained from interviews with the founders of some 61 new independent firms in South Wales. Further information is derived from interviews with representatives of the major banks and support agencies in the Principality. The study, therefore, provides data which allows a comprehensive comparison with studies of other areas and an assessment of the new firm formation process in Wales. Information is provided on both the initial start-up and the development of new and independent firms. This study also makes a contribution to knowledge in several other areas:- 1. It outlines a method to estimate the importance of new firms in employment generation in Wales. This method could usefully be extended to other regions and indeed to the U.K. as a whole. 2. It provides statistics on the size distribution of firms in the private manufacturing sector of Industrial South Wales which can also be classified according to ownership status. A potentially important factor in the new firm formation process. 3. It shows that existing theories of price determination are largely inadequate at describing methods of new firm pricing. Data are presented on the pricing practices of firms when they first enter a market and a representative model of pricing methods in new firms is suggested. 4. It attempts to relate various microeconomic concepts to the very specialised situation found in new firms,both at the time of start-up and during the infant stage of business development. Barriers to entry, scale and location decisions and limits to firm growth are considered in this context.

This thesis is concerned with the earthwork and timber castles built in the southern March of Wales between the periods AD 1050-1250. The research addresses the presence of the castles and discusses their roles as weapons of conquest and structures of administrative control. It is argued that the recognisable change in the form of earthwork castle construction over the 200 year period can be seen as a consequence of changing functions. Although it has not been possible to demonstrate how the area within a castle was used, it has been possible to identify a difference in the degree of defence verses habitation space associated with these structures. A system of classification is introduced which relies on the tenet of "form follows function" whereby all of the known earthworks are interpreted as to type and date; the date periods being generalised into the 11 th, 12th and 13 th centuries. The information for the classification is derived from a variety of sources; documentary evidence, fieldwork, aerial photography, topographical survey, geophysical survey, and limited excavation. The surveys and excavations that are included are original work undertaken for this study. Discussion has also been undertaken as to the social structures in the March both prior to the Norman Conquest and after the arrival of the Normans. Research is also presented with a view to questioning both the origin of the castle and the definition of the term. The research uses a certain amount of data from outside of the area including Normandy. The outcome of the research presents an interpretation of the Norman Conquest of theSouthern March of Wales.

No description available.