The memoirs of C.S. Douglas
- Authors: Douglas, Cuthbert Sholto
- Date: 2015-06-05
- Subjects: Surveying -- South Africa -- History , Surveyors -- South Africa -- Biography
- Language: English
- Type: Text
- Identifier: vital:547 , http://hdl.handle.net/10962/d1018500
- Description: In this transcription of original memoirs, Cuthbert Sholto Douglas, 21.1.1887 - 6.8.1973, the son of a Methodist minister, describes his youth in Sea Point, and his studies in Land Surveying in Cape Town in the early years of the 20th century. His early career as a surveyor took place in Piet Retief, before he joined the Department of Irrigation. His responsiblities included work on the Hartebeespoort Dam, and the reconnaissance into the feasibilty of the Kalahari water scheme proposed by Prof. Schwartz. He worked on the Sundays River Valley irrigation canals, before proceeding to work in Bloemfontein, Pietermaritzburg and finally Pretoria as Surveyor General. His memoir contains numerous interesting details of life in the field in the early days of land surveying in South Africa, as well as the social history of the time. He was married to Honor Broadhead, daughter of a Methodist minister, and father of Sholto, Kenneth, Hugh and Malcolm Douglas. , Donated by Geoff Douglas, 2015
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Is inflation targeting a viable option for a developing country?: the case of Malawi
- Authors: Hompashe, Dumisani MacDonald
- Date: 2009
- Subjects: Inflation (Finance) -- Malawi -- Case studies , Banks and banking, Central -- Malawi , Monetary policy -- Malawi , Finance -- Developing countries , Debts, External -- Developing countries
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:943 , http://hdl.handle.net/10962/d1002676 , Inflation (Finance) -- Malawi -- Case studies , Banks and banking, Central -- Malawi , Monetary policy -- Malawi , Finance -- Developing countries , Debts, External -- Developing countries
- Description: The distinctive features of inflation targeting include the publishing of the formal (official) target band or point target for the rate of inflation at one or more time horizons and the explicit confirmation that low and steady inflation is the long-run objective of monetary policy. There are four main preconditions of inflation targeting: 1) an independent central bank that is free from fiscal and political pressures; 2) a central bank that has both the ability to forecast inflation and the capability to model inflation data; 3) the presence of fully deregulated prices and an economy that is affected by changes of commodity prices, as well as exchange rates; and 4) the presence of sound banking system and well developed capital markets. In most developing countries, the use of seigniorage revenues as a source of financing government debts, the lack of commitment by monetary authorities to low inflation as a primary goal, the absence of the central bank’s functional independence, and of powerful models to make domestic inflation forecasts, prevent the satisfaction of these preconditions. This dissertation investigates the extent to which Malawi meets the preconditions for inflation targeting by comparing the situation in that country to other developing countries, which have already adopted the framework. Malawi is committed to the central bank’s functional independence as well as the pursuit of prudent fiscal policy measures for the attainment of low inflation. Despite the failure to meet all the preconditions, this study recommends that Malawi should adopt an inflation targeting framework due to the strength of commitment of the monetary authorities in satisfying these preconditions.
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- Date Issued: 2009
Importance of various data sources in deterministic stock assessment models
- Authors: Northrop, Amanda Rosalind
- Date: 2008
- Subjects: Fish stock assessment -- Mathematical models , Fishery management -- Mathematical models , Fish populations -- Mathematical models , Error analysis (Mathematics) , Fishery management -- Statistical methods , Fish stock assessment -- Statistical methods
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5571 , http://hdl.handle.net/10962/d1002811 , Fish stock assessment -- Mathematical models , Fishery management -- Mathematical models , Fish populations -- Mathematical models , Error analysis (Mathematics) , Fishery management -- Statistical methods , Fish stock assessment -- Statistical methods
- Description: In fisheries, advice for the management of fish populations is based upon management quantities that are estimated by stock assessment models. Fisheries stock assessment is a process in which data collected from a fish population are used to generate a model which enables the effects of fishing on a stock to be quantified. This study determined the effects of various data sources, assumptions, error scenarios and sample sizes on the accuracy with which the age-structured production model and the Schaefer model (assessment models) were able to estimate key management quantities for a fish resource similar to the Cape hakes (Merluccius capensis and M. paradoxus). An age-structured production model was used as the operating model to simulate hypothetical fish resource population dynamics for which management quantities could be determined by the assessment models. Different stocks were simulated with various harvest rate histories. These harvest rates produced Downhill trip data, where harvest rates increase over time until the resource is close to collapse, and Good contrast data, where the harvest rate increases over time until the resource is at less than half of it’s exploitable biomass, and then it decreases allowing the resource to rebuild. The accuracy of the assessment models were determined when data were drawn from the operating model with various combinations of error. The age-structured production model was more accurate at estimating maximum sustainable yield, maximum sustainable yield level and the maximum sustainable yield ratio. The Schaefer model gave more accurate estimates of Depletion and Total Allowable Catch. While the assessment models were able to estimate management quantities using Downhill trip data, the estimates improved significantly when the models were tuned with Good contrast data. When autocorrelation in the spawner-recruit curve was not accounted for by the deterministic assessment model, inaccuracy in parameter estimates were high. The assessment model management quantities were not greatly affected by multinomial ageing error in the catch-at-age matrices at a sample size of 5000 otoliths. Assessment model estimates were closer to their true values when log-normal error were assumed in the catch-at-age matrix, even when the true underlying error were multinomial. However, the multinomial had smaller coefficients of variation at all sample sizes, between 1000 and 10000, of otoliths aged. It was recommended that the assessment model is chosen based on the management quantity of interest. When the underlying error is multinomial, the weighted log-normal likelihood function should be used in the catch-at-age matrix to obtain accurate parameter estimates. However, the multinomial likelihood should be used to minimise the coefficient of variation. Investigation into correcting for autocorrelation in the stock-recruitment relationship should be carried out, as it had a large effect on the accuracy of management quantities.
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- Date Issued: 2008
The fisheries potential of Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius in Mnjoli dam, Swaziland
- Authors: Khumalo, Nokuthula
- Date: 2006
- Subjects: Mozambique tilapia , Marcusenius pongolensis , Schilbe intermedius , Fishes -- Swaziland , Fisheries -- Swaziland , Tilapia -- Swaziland
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5283 , http://hdl.handle.net/10962/d1005127 , Mozambique tilapia , Marcusenius pongolensis , Schilbe intermedius , Fishes -- Swaziland , Fisheries -- Swaziland , Tilapia -- Swaziland
- Description: This thesis investigates aspects of the diversity, abundance and biology of the fish species inhabiting Mnjoli Dam, an irrigation dam that is located in the rural lowveld region of Swaziland. Specific objectives for this thesis were: to determine the fish species present and select three principal species based on their abundance; to investigate the relative abundance and distribution of the three selected species; and to describe key population parameters, such as growth, maturity, reproductive seasonality and mortality. The three dominant species were selected on their fisheries potential. These were Marcusenius pongolensis, Oreochromis mossambicus and Schilbe intermedius. Marcusenius pongolensis was the most abundant species in terms of both catch per unit effort and mass. Catch rates were shown to vary according to habitat type. Age and growth parameters were obtained from sectioned otoliths. Marginal zone analysis showed that annulus formation occurred in winter for all three species. The maximum-recorded ages were 8, 6 and 8 for M. pongolensis, O. mossambicus and S. intermedius, respectively. Growth for the three species was best described by the three parameter von Bertalanffy growth model as Lt = 1.88.67(1- exp⁻¹·⁴⁸⁽t⁺°·⁶⁷⁾) mm FL for M. pongolensis; Lt = 226.83(1- exp⁻°·⁴⁽t⁺²·°²⁾) mm TL for O. mossambicus and Lt = 214.59(1- exp⁻°·⁶°⁽t⁺¹·²°⁾) mm FL for S. intermedius. Sexual maturity was estimated for male and female M. pongolensis at 134 mm FL and 119 mm FL, respectively. Oreochromis mossambicus matured at 239 mm TL and S. intermedius at 205 mm FL. Two spawning peaks for M. pongolensis and S. intermedius were observed, one at the onset of summer (November) and the second at the beginning of autumn (February-March). Oreochromis mossambicus also exhibited two spawning peaks, one in spring (September) and the second in autumn (February –March). Mean mortality rate (Z), estimated using catch curve analysis was 0.77 year⁻¹ for M. pongolensis, 0.49 year⁻¹ for O. mossambicus and 0.79 year⁻¹ for S. intermedius. Natural mortality was assumed to be equal to Z since there is no fishery activity at the dam. Size specific selectivity curves were developed for each species. Of all the mesh sizes used, the 44 mm mesh size net had the highest catch rates in terms of numbers for M. pongolensis and S. intermedius. The 75mm mesh caught the highest catch rates for O. mossambicus. . The 44mm and 75 mm meshes seem to be the most suitable mesh sizes for harvesting the candidate species. It is concluded that no commercial fishery should be established on the dam, yet a small subsistence fishery could be a possible option. Management options such as input controls, open and closed seasons and areas and minimum sizes are discussed.
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- Date Issued: 2006
Locating the institution of traditional leadership within the institutional framework of South Africa's new democracy
- Authors: Mashele, Hlukanisa Prince
- Date: 2003
- Subjects: Tribal government -- South Africa , Political leadership -- South Africa , South Africa -- Politics and government -- 1994-
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2858 , http://hdl.handle.net/10962/d1007512 , Tribal government -- South Africa , Political leadership -- South Africa , South Africa -- Politics and government -- 1994-
- Description: This study looks into the role of the institution of traditional leadership in post-apartheid South Africa. It seeks to critically engage the debate on how to locate the institution within the new politico-constitutional framework. This is done with the main objective of proposing an altemative to the current state of affairs vis-à-vis traditional leadership and governance in South Africa. In order to clear the ground, the study first deals with the important question of democracy in relation to the institution of traditional leadership. In this regard, the study unearthed that the institution of traditional leadership is fundamentally undemocratic in character, as it is largely based on heredity and devoid of principles of democracy such as equality, accountability, etc. In order to put matters into perspective the study also delves into the history of the institution of traditional leadership with the aim of getting to the role that traditional leaders played in various epochs of South Africa's political development. This investigation reveals that the denting of the integrity of the institution of traditional leadership began with the advent of colonialism and worsened by successive apartheid regimes. It is at these stages of development that the institution was subordinated to a higher authority that sought to use the institution as an instrument of domination and oppression of the black majority. Considering this role, it would seem that the place that the space that the institution occupies in the post-apartheid South African governance framework is a compromise. The institution plays an advisory role at all levels of government - with their houses in both national and provincial legislatures, whilst traditional leaders sit as ex-officio members on local councils. However, traditional leaders fiercely contest this position as, in their view, this limits their powers. The main argument of this study is that for traditional leaders to be given an advisory role in the current and future governance framework of the country is a step in the right direction, as that serves to insulate the institution from active politics. For that reason, the study recommends that the institution of traditional leadership should occupy a cultural space in society - meaning that it should be responsible for the preservation of African customs and culture. This, therefore, means that the institution is better-placed to advise government on cultural and customary aspects of development. Whilst playing this role, the institution of traditional leadership should also -be brought into line with democratic ways of governance.
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- Date Issued: 2003
The role of vitamin E succinate in regulation of growth and cyclooxygenase expression in B16 murine melanoma cells
- Authors: Van der Merwe, Adele Shanette
- Date: 1999
- Subjects: Melanoma , Vitamin E
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3988 , http://hdl.handle.net/10962/d1004047 , Melanoma , Vitamin E
- Description: This study was undertaken to determine the effects and possible mechanism of action of vitamin E succinate supplementation on B16 murine melanoma cell growth in vitro. Studies revealed that supplementation of 5, 7 and 10µg/ml of this vitamin significantly inhibited growth of B16 cells. Non-malignant LLCMK cells supplemented with the same concentrations of vitamin E succinate resulted in similar inhibition of cell growth. The actual mechanism by which vitamin E succinate inhibits B16 cell growth is unclear, though there has been much speculation about its possible role as an antioxidant. Vitamin E succinate is not a physiological antioxidant and for this ester to behave as an antioxidant, cleavage of the ester bond must occur, releasing the antioxidant vitamin E part of the molecule. To determine whether the observed inhibitory effects on B16 cell growth were due to the intact vitamin E succinate or the vitamin E cleavage product, cleavage studies were undertaken. Results from these studies revealed that in B16 cells vitamin E succinate cleavage did not occur suggesting that the observed inhibitory effects of vitamin E succinate on B16 cells were due to the intact compound. In contrast vitamin E succinate cleavage was shown to occur in LLCMK cells, suggesting that these cells may contain an esterase capable of liberating succinic acid and vitamin E. Further studies focussed on the possible role of vitamin E succinate in regulation of cyclooxygenase activity in B16 cells as vitamin E succinate was found to effect the activity of various enzymes involved in the arachidonic acid cascade, notably cyclooxygenase, the rate-limiting enzyme in prostaglandin synthesis. Time course studies were used to determine when the cyclooxygenase protein was being produced, thus allowing an estimation of when the gene was being 'switched on'. These studies revealed that vitamin E succinate does not significantly effect cyclooxygenase activity in B16 cells over a period of 2 to 12 hours as compared to the OE control cultures. Further studies using RNA techniques investigated whether vitamin E succinate was having an effect on cyclooxygenase activity at a molecular level. These investigations were unsuccessful for the 6 day supplementation for a number of possible reasons, the main reason being RNA stability. Subsequent studies revealed an increase in COX mRNA after 2 hours, suggesting that the gene was 'switched on' soon after supplementation with vitamin E succinate, and further increases in COX mRNA were observed after 8 to 12 hours. The molecular studies were, however, inconclusive. Previous studies suggested that vitamin E succinate was indirectly causing growth inhibition of B16 cells via regulation of cyclooxygenase activity, however, this study does not support these findings and it would seem unlikely that regulation of cyclooxygenase expression in B16 cells by vitamin E succinate has a role to play in the mechanism by which vitamin E succinate inhibits growth in B16 cells.
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- Date Issued: 1999