Geological and geophysical investigations of groundwater resource in the area of Ndlambe Municipality, Eastern Cape Province, South Africa.
- Authors: Mpofu, Mthulisi
- Date: 2020
- Subjects: Groundwater Geophysical surveys
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: http://hdl.handle.net/10353/18755 , vital:42730
- Description: Groundwater is an essential resource contributing extensively to overall total annual supply. However, overexploitation has depleted groundwater availability significantly and also brought about land subsidence at some places. The evaluation of groundwater potential zones is essential in protecting the quality of water and managing of groundwater structures. The Eastern Cape Province is one of the provinces faced with the challenge of supplying clean fresh water to the communities residing in it. Ndlambe municipality is a case in point where people rely on groundwater for agriculture and domestic activities. Few studies have been undertaken to evaluate groundwater resource in the study area. This study aims to assess groundwater resources as a way of achieving the goal of water sustainability. In the southeast of the Cape Fold Belt (CBF), is the Ndlambe municipality underneath folded Cape and Karoo Supergroup rocks. The rock sequence in the region reflects the geological history over a considerable period. In general, the area of study comprises of the Bokkeveld and Witteberg groups. The Bokkeveld comprises of shale along with sandstone whilst the Witteberg Group consists predominantly of quartzites with minor interbedded shales. The aims of the study were to target potential zones for groundwater exploration, analyse zones of lineaments, investigate the networks of fractures and the mineralogy of the area of study. In line with studies for groundwater exploration, a number of methods were undertaken for obtaining the results. These included literature review, remote sensing and geographic information system, thin section analysis, scanning electron microscope (SEM), X-ray fluorescence (XRF), structural analysis and geophysical investigations (magnetic and vertical electrical sounding). Potential zones for groundwater were identified using remote sensing techniques and geographical information systems (GIS). Maps were generated using GIS tools. Geology, slope, lineaments and Normalised Difference Vegetation Index (NDVI) were considered as parameters for determining groundwater potential zones. A geological and geophysical study was conducted in the Ndlambe municipality. Twelve samples for thin sections, 12 samples for XRF analysis and 4 samples for SEM analysis were collected at different locations in the area of study and were analysed. Thin section analysis revealed that quartz arenite has been metamorphosed to quartzite due to high pressure and temperatures and the cracks in the quartz grains are due to pressure and brittle deformation that has in turn enhanced secondary porosity resulting in joints and fractures which are good for groundwater movement. Scanning electron microscopy complemented the findings from optical microscopy by revealing splatter pores which are due to intense fracturing and these contribute to increasing permeability of the rock structures. XRF revealed the chemical composition of various rock types in the area of study. The analysed samples were dominated by silica reflecting their source from weathering of silicate rocks. The Chemical Index of Alteration (CIA) and Al2O3 values of the analysed samples reflected moderate to intensive weathering. In the study area, three main hydrogeologically important structures were taken into account. These included primary structures (bedding), contacts (geological) and secondary structures like fractures and folds. The study area comprises of several faults that are an important factor for porosity and permeability. The study area is dominated by blocky quartz veins that have been crushed due to compression hence higher permeability of groundwater. The Syscal Pro multichannel resistivity equipment was used to conduct the survey using the Schlumberger- Dipole-dipole array on three lines of varying length (350 m, 530 m and 340 m). Data collected were processed using RES2DINV software, producing a subsurface 2-D geoelectrical model from the pseudosections of apparent resistivity. Low resistivities in the study area were inferred to be weathered moist sandstone while low resistivities with depth indicated an overlying zone of fractured sandstone and quartzite which may be hosting some groundwater. An area of low resistivity zones between two large bodies suggests that the massive rock bodies are being weathered and fractured and fractures act as conduits for groundwater. High resistivity values indicate hard rock bodies that are unweathered hence low potential zone for groundwater localisation. The ground magnetic survey was used to delineate the subsurface structures as these control groundwater potential.
- Full Text:
- Date Issued: 2020
Uhlalutyo lwenoveli kamahala ethi: yakhal’ indoda (2010).
- Authors: Nyiki, Phumelela Sibahle
- Date: 2020
- Subjects: Literature
- Language: English
- Type: Thesis , Masters , MA (African Languages)
- Identifier: http://hdl.handle.net/10353/18257 , vital:42246
- Description: The aim and scope of this study is to analyse the novel Yakhal’ Indoda (2010) written by Siphiwo Mahala. Since this book was written in the period known as the modern times in the new South Africa, it therefore tends to focus on the issues that disturb the peace of the citizens of South Africa exactly in this period of democratic South Africa. For that reason, the objective of this study is to associate the factors which Mahala has written about with those that are found in the contemporary South Africa which are regarded as issues disturbing the lives of South Africans at present. As it is of importance before the researcher deals with the central issue, there has to be a thorough knowledge of the theory of the subject that is being discussed at hand. The Literature Review with regard to this study takes into account the books written by Satyo, Duka, Brooks and Warren, to mention just a few. These authors, from their different academic perspectives, do their best on explaining the theory of the issues that will be discussed in this study. The Theoretical Framework that will be used in this study consists of the views of the writers who fought for a better political dispensation in the countries that were previously colonized. In this regard, the views of Ngùgì wa Thiong’o, and those of Steve Biko will be assessed in this study. The method that will be used in conducting this research is none other than that of Text Analysis. This simply means the researching student will focus mainly on the books found at the UFH library and other libraries. The chapter titles and their relevant outlines follow below: Chapter One is an introduction for this entire research. This chapter focuses more on the aims of this study, the importance or significance, limitations, methodology to be followed. Furthermore, this chapter gives a brief background of the author of the novel that will be analysed as well as the background of the novel. Chapter Two focuses on the theory of this research. This will be done through two theories. The researcher will first present a theory of the novel, as well as the Postcolonial theory. Under the novel theory, the researcher will discuss some vii features of the novel. However, the researcher’s emphasis will be on the theme that underlies in Mahala’s novel, Yakhal’ Indoda (2010). Chapter Three focuses on the theme of this research. The researcher will analyse the way Mahala portrays crime, corruption, unemployment and poverty in his novel. The researcher then will validate Mahala’s point of view against other authors with regards to the identified problems. Chapter Four focuses on the problems found in the Department of Education as well as rights of women as depicted in Mahala’s novel, Yakhal’ Indoda (2010). This will be accomplished through validation of the experienced and witnessed events in the new South Africa. Chapter Five focuses on the factors and events that are commonly associated with the Departments of Health and in Local Government, which are life threatening to society. This will be done by the researcher, pointing out some problems that Mahala in his book Yakhal’ Indoda (2010) attributes to the mentioned departments. Chapter Six is the general conclusion and exegesis on the study. This chapter gives a brief summary of the previous chapters, the findings regarding this study.
- Full Text:
- Date Issued: 2020
The influence of overwash and breaching events on the spatial and temporal patterns in ichthyofauna community composition in a temporarily open/closed southern African estuary
- Authors: Tweddle, Gavin Paul
- Date: 2013
- Subjects: Estuarine fishes -- Africa, Southern Marine fishes -- Africa, Southern Fishes -- Breeding -- Africa, Southern Fishes -- Effect of habitat modification on -- Africa, Southern Fishes -- Spawning -- Africa, Southern Gobiidae -- Africa, Southern Estuaries -- Africa, Southern Estuarine ecology -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5610 , http://hdl.handle.net/10962/d1002957
- Description: This study assessed the importance of overwash and breaching events on the ichthyofaunal community structure in the medium-sized temporarily open/closed Mpekweni Estuary located on the southeast coastline of southern Africa. The fish in the littoral zone of the estuary were sampled using a 5m seine net while the channel region was sampled using two nets, a smaller meshed 30m seine net to target the estuarine spawning species and the juvenile estuarine-dependant marine spawners, and a larger meshed 50m seine net to target the larger marine and freshwater spawning species. Intensive monthly sampling over two years provided data on selected physico-chemical and biological parameters. During the two year sampling period from November 2005 to October 2007 the estuary breached in late July 2006 and remained open till the sandbar re-formed across the mouth in late December 2006. Thus, sampling encompassed three open/closed phases 1) initial closed period, 2) open period and 3) re-closed period after the berm was re-formed. The open period was divided into two phases 1) the out-flow phase and 2) the tidal phase. A total of 36 fish species representing 19 families were sampled using the various seine nets employed during the investigation. In the littoral zone, the estuarine spawners (Estuarine Utilisation Category, [EUC] I), mainly the Gobiidae, Glossogobius callidus, dominated the samples numerically and by biomass. The smaller estuarine spawning species sampled in the channel were numerically dominated by Gilchristella aestuaria in conjunction with two other EUC I species, Atherina breviceps and G. callidus. The estuarine-dependant marine spawners (EUC II), however, dominated the ichthyofaunal biomass of the channel. The abundance and biomass of the larger species targeted were dominated by estuarine-dependant marine spawning species (EUC II), principally Rhabdosargus holubi. During the closed periods of the estuary, total fish abundance and biomass displayed weak seasonal patterns. The breaching event and subsequent open period was associated with a decrease in the total abundances of fish in the littoral zone and channel of the estuary, reflecting the out-flow of estuarine biomass-rich water into the marine environment. The breaching event coincided with a shift in the community composition of the ichthyofauna, reflecting the recruitment of marine spawning species into the estuary. Numerical analysis identified two distinct spatial fish communities within the estuary, a community associated with the mouth region and one comprising the rest of the estuary. The absence of any further spatial patterns in the ichthyofaunal community structure within the Mpekweni Estuary appear to be ascribed to the virtual absence of horizontal patterns in physico-chemical and biological parameters recorded in the system. Cohort analyses were employed to determine possible recruitment events for selected estuarine and marine spawning species. The estuarine spawning species displayed continuous recruitment patterns throughout the study, which appeared to be unaffected by the breaching event. Conversely, the larger marine spawning species displayed multiple cohorts, indicating non-continuous recruitment. Subsequent retrospective analysis of cohorts for the different species identified summer recruitment peaks that coincided with the breaching event and open period. Minor recruitment of marine spawning species also occurred during overwash events. The recruitment of ichthyofauna into the estuary was quantified during three distinct hydrological events: overwash, out-flow phase immediately after breaching and tidal phase during the period when the mouth was open. Estimates of fish recruitment were highest during the outflow phase immediately after the estuary breached and declined as the estuary became tidally inundated with marine water. Although not as high as the outflow and tidal phases, recruitment was evident during overwash events. Results of the current study highlight the importance of both breaching and overwashing events in structuring the ichthyofaunal community composition in a medium-sized southern African temporarily open/closed estuary. These results are broadly in agreement with similar studies conducted both locally and in other regions of the world.
- Full Text:
- Date Issued: 2013
User requirements framework for mobile government in the Western Cape
- Authors: Wilson, Fiona Michelle
- Date: 2013
- Subjects: Government communication systems , Internet in public administration , Electronic government information , Mobile communication systems , Information technology
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:9751 , http://hdl.handle.net/10948/d1008076 , Government communication systems , Internet in public administration , Electronic government information , Mobile communication systems , Information technology
- Description: Globally, mobile technology use, particularly the use of mobile phones, is becoming increasingly widespread. One consequence of this growth is mounting interest in using mobile technologies in the public sector, particularly in developing countries, because it is seen as enabling better access to information and services for citizens. Mobile government (m-government), defined as the use of mobile technologies and applications for public sector services, promises to extend access to public services to marginalised sectors of the population and is emerging as a new focus in the ongoing challenge to provide efficient, effective and accessible public services. Though interest in m-government is emerging in the provincial Western Cape Government (WCG) of South Africa, few guidelines exist in the WCG to inform the development of public sector mobile services. This absence impacts on service delivery and the primary objective of this study was to propose a set of guidelines that could guide the prioritisation of citizen facing public sector services for mobile implementation in the Western Cape. The study considered two areas namely, government and user needs. The primary research question was to determine what public sector services citizens need and how these services should be prioritised for mobile delivery in the Western Cape. To address this, three research sub-questions were formulated. The first question aimed to examine conceptions of mobile government. To achieve this a literature study and documentation review was conducted, from which factors influencing service prioritisation emerged. The second research question aimed to identify citizen needs that could inform mobile public sector services in the Western Cape. Thus a survey and interviews were conducted with citizens using the WCG community ICT centres (e-Centres). The third research question aimed to identify factors that impact on the prioritisation of citizen facing public sectors for mobile delivery in the Western Cape. The findings from the literature study, survey and interviews conducted were used to address this research question. The results from the three research sub-questions were triangulated to address the main objective of the study and from this a set of guidelines for prioritising mobile public sector services in the Western Cape was proposed.
- Full Text:
- Date Issued: 2013
Illustrated medicines information for HIV/AIDS patients: influence on adherence,self-efficacy and health outcomes
- Authors: Barford, Kirsty-Lee
- Date: 2012
- Subjects: AIDS (Disease) -- Treatment -- South Africa , HIV infections -- Treatment -- South Africa , AIDS (Disease) -- Patients -- South Africa , HIV-positive persons -- South Africa , AIDS (Disease) -- Study and teaching -- South Africa , Antiretroviral agents -- South Africa , Communication in medicine -- South Africa , Communication in public health -- South Africa
- Language: English
- Type: Thesis , Masters , MPharm
- Identifier: vital:3863 , http://hdl.handle.net/10962/d1015678
- Description: South Africa has an estimated 920 000 patients on antiretrovirals (ARVs), the largest number of patients in any country. ARV therapy demands adherence levels in excess of 95% to avoid development of drug resistance, but adherence to ARV therapy is estimated to be only between 50% and 70%. Poor medication adherence is acknowledged as a major public health problem, reducing the effectiveness of therapy and promoting resistance to ARVs. More than two thirds of the South African population have marginal reading skills and this significantly influences a patient’s ability to read and understand health-related information. Patient education materials tailored for the South African population could be a useful aid in facilitating communication with patients and perhaps impact positively on their medicine-taking behaviour. This behaviour is influenced by patient knowledge, beliefs, attitudes and expectations and includes self-management, self-efficacy and adherence. Self-efficacy, which refers to patient confidence in the ability to self-manage medicine taking, is a key factor influencing adherence. This study aimed to develop illustrated patient information leaflets (PILs) and medicine labels for all first-line ARV regimens used in the public health sector in South Africa and, using a randomised control study design, to investigate the impact of these illustrated information materials on knowledge, medication-taking behaviours and health outcomes in HIV/AIDS patients taking ARVs. To achieve this aim, the objectives were to assess HIV/AIDS and ARV-related knowledge, as well as self-efficacy and adherence to ARV therapy; to assess the influence of demographic variables on knowledge, adherence and self-efficacy; to assess the influence of the information materials on knowledge, self-efficacy and adherence and to assess the association of knowledge with health outcomes. Medicine labels and PILs, both English and isiXhosa, were developed for ARV regimens 1a, 1b, 1c and 1d. The 8-item Morisky Medication Adherence Scale (MMAS-8) and HIV Treatment Adherence Self Efficacy Scale (HIV-ASES) instruments for measuring respectively adherence and self-efficacy, were modified to optimize clarity, simplicity and cultural acceptability and were translated into isiXhosa using a multi-stage translation-back translation. The questions and the rating scales, for both the MMAS and HIV-ASES, underwent preliminary qualitative evaluation in focus group discussions. Patients were recruited from local Grahamstown clinics. A pilot study to evaluate applicability of the instruments was conducted in 16 isiXhosa AIDS patients on ARVs and the results from this study informed further modifications to the instruments. One hundred and seventeen patients were recruited for the randomised control trial and were randomly allocated to either control group (who received standard care) or experimental group (who received standard care as well as pictogram medicine labels and the illustrated PIL). Interviews were conducted at baseline and at one, three and six months. Data were analysed statistically using the t-test, chi-squared test and ANOVA (Analysis of Variance) at a 5% level of significance. Correlations were determined using Pearson and Spearman rho correlations. Approval was obtained from Rhodes University Ethical Standards Committee, Settlers Hospital Ethics Committee and the Eastern Cape Department of Health. The results of this research showed that illustrated PILs and medicine labels enhanced understanding of HIV/AIDS and ARV information, resulting in a mean overall knowledge score in the experimental group of 96%, which was significantly higher than the 75% measured in the control group. Variable knowledge scores were measured in three areas: baseline knowledge of general HIV/AIDS-related information was good at 87%, whereas knowledge scores relating to ARV-related information (60%) and side-effects (52%) were lower. These scores improved significantly in the experimental group over the 4 interviews during the 6 month trial duration, whereas in the control group, they fluctuated only slightly around the original baseline score. There was no significant influence of gender on knowledge score, whereas health literacy, education level and age tested (at one and three months) had a significant influence on knowledge. Self-efficacy and adherence results were high, indicating that the patients have confidence in their ability to adhere to the ARV therapy and to practice optimal self-care. Age, gender and education, in most cases, significantly influenced self-efficacy, but were found to have no effect on adherence. The CD4 count improved over the trial duration which may have been influenced by a number of factors, including better knowledge of ARVs and improved adherence. No significant parametric correlation was found between knowledge score and change in CD4 count, however, Spearman's rho showed significance (rs=0.498; p=0.022). Both patients and healthcare providers were highly enthusiastic about the illustrated labels and PILs, and indicated their desire for such materials to be routinely available to public sector HIV/AIDS patients. The isiXhosa version of the PIL was preferred by all the patients. These simple, easy-to-read leaflets and illustrated medication labels were shown to increase understanding and knowledge of ARVs and HIV/AIDS in low-literate patients, and their availability in the first-language of the patients was central to making them a highly useful information source.
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- Date Issued: 2012
An investigation of the role of principals in promoting computer usage in selected Namibian schools
- Authors: Katulo, Mighty Masiku
- Date: 2010
- Subjects: Computers -- Study and teaching -- Namibia Educational technology -- Namibia Information technology -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1658 , http://hdl.handle.net/10962/d1003541
- Description: Globalisation and technology change have created a new global economy fuelled by information and driven by knowledge. Information and Communication Technologies (ICT) have been touted as potential powerful tools for enabling educational change and reform. Namibia is among those countries that have adopted the use of ICTs as a vehicle for change. This thesis explores the role of school principals in promoting and managing computer usage in selected schools in Namibia. The study was conducted at four schools in the Caprivi Region. The study employed a qualitative case study to collect and analyse data. A total of four school principals and four computer coordinators were interviewed, and responded to questions pertaining to the role of principals in the following areas: acquiring ICT equipment; providing access to the computer labs; promoting the use of computers; maintaining computers; capacity-building of teachers, and addressing challenges that could prevent computer usage. Two focus group interviews were also conducted at two schools, to find out what they perceived to be the role of school principals in supporting and ensuring the effective use of computers in schools. The findings on acquisition of computers reveal that principals were often the initiators of the acquisition process. Ministerial deployment is the most common form of acquisition, followed by the use of the school’s development fund to purchase administrative computers. Only one of the participating schools did not acquire its computers through Ministerial deployment. Some schools were more resourced than others. Availability and maintenance of equipment depended on the kind of school (advantaged or disadvantaged) and the way the computers were acquired rather than on the role of the principal. Schools that acquired their computers through the ministerial deployment received satisfactory technical support from the ministry while schools that acquired their computers through other sources had to rely more heavily on the principal to pro-actively seek support. School principals that demonstrated the qualities of transformational leadership promoted the usage of computers by taking part in training offered to teachers and encouraged teachers on different platforms to make use of computers. The study also found that schools in which principals actively supported and promoted the use of computers were successful in the usage of the computer labs, while in schools where principals left the running of the computer lab to an individual teacher, the usage was minimal. It was found that a number of challenges are hampering the usage. These include lack of internet connectivity, qualified personnel to cascade training, and minimum infrastructure. The study recommends that school principals should adopt trategies that encourage teachers to use computers in their daily routines. It also makes suggestions for further research on the impact of school culture on ICT integration.
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- Date Issued: 2010
The influence of organisational culture on organisational commitment at a selected local municipality
- Authors: Van Stuyvesant Meijen, Jolise
- Date: 2008
- Subjects: Local government -- South Africa , Corporate culture -- South Africa , Organizational change -- South Africa , Municipal services -- South Africa , Employee loyalty
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1172 , http://hdl.handle.net/10962/d1002788
- Description: Since 2000, local municipalities have been through a process of transformation which amalgamated a number of smaller local municipalities into larger municipalities. The amalgamation of a number of municipalities brings together an array of people, and therefore a myriad of organisational cultures are combined. The organisational culture of an organisation has an effect on the organisational commitment of its employees. A fit between the organisational culture and the employees will increase the organisational commitment of those employees and contribute towards improved service delivery. A survey conducted in South Africa indicated that the local municipalities have been delivering poor standards of service to the community; therefore there is a need to increase the service delivery within local municipalities. The importance of looking at the organisational commitment of a local municipality is because if there is commitment within the organisation, then employees will identify with their organisation and its goals, and will deliver the service more effectively and efficiently. Therefore, increasing the service delivery of local municipalities can be achieved through diagnosing the organisational commitment and organisational culture of employees within the selected municipality. The primary objective of this research was therefore to diagnose the relationship between organisational culture and the organisational commitment of employees at the selected municipality. In order to achieve this objective, a survey was conducted to canvas the opinions of respondents (N = 148) from the selected local municipality regarding their perceptions of the existing organisational culture, their preferences regarding the organisational culture within the selected municipality, and finally the organisational commitment. The main findings of this research conducted at a selected municipality can be summarised as follows: The dominant existing organisational culture is the power culture, while the dominant preferred organisational culture is the support culture; There is an organisational culture gap between the existing and preferred organisational cultures at the selected municipality; The dominant organisational commitment within the selected municipality is normative commitment; The findings pertaining to the relationship between organisational culture and organisational commitment of employees within the selected municipality can be stated as follows: The existing organisational cultures have significant effects on the organisational commitment of employees; The preferred organisational cultures do not have significant effects on the organisational commitment of employees; and The organisational culture gap does not have a significant effect on the organisational commitment of employees; The findings pertaining to the relationship between the biographical variables and the existing and preferred organisational culture, organisational commitment and the organisational culture gap can be stated as follows: There is no significant relationship between biographical variables and the existing organisational culture; There are significant relationships between the biographical variables, namely the departments in which respondents work, and the education level of respondents, and the preferred organisational culture; There are significant relationships between the biographical variables and organisational commitment; and The average organisational culture gap scores of the organisational culture scales for the biographical variables are significantly different. It can be concluded that organisational culture has a significant effect on the organisational commitment of employees within the selected municipality and therefore can affect the service delivery of the selected municipality.
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- Date Issued: 2008
The development and application of ecological risk assessment in South African water resource management
- Authors: Claassen, Marius
- Date: 2006
- Subjects: Ecological risk assessment -- South Africa Water resources development -- South Africa Water quality management -- South Africa Water-supply -- Management -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:6036 , http://hdl.handle.net/10962/d1006177
- Description: The provision of goods and services by aquatic ecosystems plays an important role in socio-economic development and livelihoods in the southern African region. Water resource management in South Africa developed from an agrarian and pastoral focus up to 1956 to also supporting mining and industrial activities. This led to the introduction of the resource water quality objectives and pollution prevention approaches, which balanced the needs for development and protection. Prior to 1994, access to water resources was limited to riparian property owners and a minority of the population who controlled industrial and mining activities. The establishment of a democratic government amplified the need for accelerated socio-economic development, with equity, efficiency and sustainability being the principles of such development. New approaches were needed, which could achieve these development objectives and secure the resource base for future generations. An overview of the scientific process highlighted a risk based approach as potentially supporting the much needed balance between development and protection. The aims of this thesis is to develop a framework and process for the application of ecological risk assessment to water resource management in South Africa, to use case studies to draft guidelines for ecological risk assessment and to assess the degree to which ecological risk assessment can contribute to effective water resource management in South Africa. The United States Environmental Protection Agency’s guidelines for ecological risk assessment were identified amongst international best practice as meeting the requirements for local application. A framework was drafted for ecological risk assessment in South Africa, with the main phases being to agree on objectives, formulate the analysis plan, analyse information, characterise risk and manage risk. Modifications from the Environmental Protection Agency’s process include the order of activities in the first phase, the explicit testing of hypotheses and clarification of the evaluation of existing data or collection of new data. An industrial effluent case study was used to assess the applicability of the proposed framework. The case study dealt specifically with the assessment of risks posed by current conditions and long term licence conditions. The framework was found to be useful to identify weaknesses in the established monitoring programme and to evaluate lines of evidence to assess the degree to which the stated conditions would have unacceptable consequences. The study highlighted several weaknesses in the suggested framework, of which the most critical is the interpretation of the risk hypothesis as a testable null hypothesis. It became clear that cause-effect relationships should be stated as the risk hypothesis, whereas the assessment should evaluate expressed or expected conditions against a risk profile for a given stressor to benefit fully from the risk assessment approach. Changes to the framework terminology were suggested as well as nested feedback loops to allow for iterative processes where new information becomes available. The proposed guidelines incorporate the learning from the case study application as well as feedback from a peer review process. The guidelines incorporate the suggested actions under each phase as well as notes providing the rationale for each step. Three case study outlines were provided to assist users with the interpretation of the guidelines in different applications. The proposed guidelines are applied in an ecological Reserve determination case study, which specified the ecological water quality requirements. The study found that a risk-based approach was followed in the development of the water resource management policy, but the Reserve determination method is generally hazard based, with site specific modifications of the target values being allowed on a conservative basis. The case study highlighted a lack of readiness of water resource managers to accommodate scientific results expressed as probability distributions in support of management decisions. The thesis is concluded with a discussion of the key learning points of the ecological risk assessment development process. The evaluation highlights the move from stating and testing a null hypothesis to stating the risk hypothesis and evaluating the stated conditions against a risk profile. Several implementation challenges are highlighted, with specific recommendations made for adopting the proposed guidelines.
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- Date Issued: 2006
The dynamics of a subtropical lake fishery in central Mozambique
- Authors: Weyl, Olaf L F
- Date: 1999
- Subjects: Fisheries -- Chicamba, Lake Fisheries -- Mozambique
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5212 , http://hdl.handle.net/10962/d1004785
- Description: Fisheries in African reservoirs are typically multi -species and in most cases the fish resource is harvested with a number of gears. These characteristics complicate their management and the development of management procedures. Typically, long time series of data on catch and effort and length- or age-based catch are not available for these fisheries. This precludes the use of data intensive methods such as multi-species virtual population analysis. The principal aim of this thesis was to develop a management procedure for African reservoir fisheries that takes into account the pertinent biological characteristics of the target species and accounts for the multi-species and multi-gear irIteractions in such fisheries. An opportunity availed itself to undertake this work on Lake ChicaIllba (19°08'S 33°08'E) a man-made hydroelectric dam in subtropical Mozambique (Manica province). The specific objectives of this study were: to obtain locality specific biological parameters for the target species in Lake ChicaIllba; to assess gear utilisation trends in the fishery through the determination of gear-selectivity, catch rate and effort for each of the principal gears used in the fishery; to assess the fishery using traditional per-recruit models and to test existing and new per-recruit models that account for the multi-species and multi-gear nature of the fishery and to determine the adequacy of each of these approaches in the determination of suitable target reference point (TRP) exploitation rates. The three principal specIes in Lake Chicamba are the introduced largemouth bass, Micropterus salmoides, and two cichlids the Mozambique tilapia, Oreochromis mossambicus and the redbreast tilapia, Tilapia rendalli. Sectioned otoliths were used for age and growth determination. Marginal zone analysis showed that annulus formation in all three species occurred during winter. The maximum-recorded age was 5 years for M. salmoides, 16 years for T. rendalli and 10 years for O. mossambicus. Growth of the three species was best described by the 3 parameter von Bertalanffy growth model as ℓa = 465.51 (1 - e⁻ₑ·ₑ⁷⁵⁽a⁺⁰·⁰⁰⁹⁾ mm FL for M salmoides; ℓa = 238.74 (1 - e⁻⁰⁶³⁶⁽a⁺⁰·⁹⁰⁵⁾) mm TL for T. rendalli; and ℓa = 266.06 (1 - e⁻⁰⁷⁹⁰⁴⁽a⁺⁰·²⁶⁹⁾) mm TL for 0. mossambicus. Female T. rendalli attained 50%-maturity at 2.89 years, while O. mossambicus matured at 2.83 years and M. salmoides at 0.9 years. Both cichlid species spawned throughout summer while M. salmoides had a very short spawning season from August to September. The total annual mortality rate (Z) for M. salmoides in Lake Chicamba was 1.27 yr⁻¹, the mean empirical estimate of natural mortality (M) was 0.73 yr⁻¹, and fishing mortality (F) was calculated at 0.54 yr⁻¹. For T. rendalli Z = 0.31 yr⁻¹, M = 0.20 yr⁻¹, F = 0.11 yr⁻¹ and for 0. mossambicus Z= 0.62 yr⁻¹, M= 0.38 yr⁻¹, F= 0.24 yr⁻¹. The three species exhibited reproductive traits, which implied a high reliance of recruitment on spawner stock (nest guarding in T. rendalli and M. salmoides and mouthbrooding in O. mossambicus). For this reason it was decided that the cichlid fisheries should be managed using TRPs which maintained the spawner biomass-per-recruit at 50% (FSB50) of pristine levels. However, based on good evidence it was hypothesised that the high rate of fishing mortality helped to maintain the fast growth rate of M. salmoides. It was, therefore, decided to manage this species at a TRP of F SB40. The three most important fishing sectors were the gill-net, seine-net and hook-and-line fisheries. The total catch for 1996 was 223 t. The gill nets selected all three species at a size/age approximating 50%-maturity while the seine-net and hook-and-line fisheries selected mainly juvenile fishes. There was strong evidence to suggest that seine net fishing also disrupted spawning. It was shown that the 'traditional' single-species per-recruit models were unsuitable to assess multi-species and multi-gear reservoir fisheries. Since existing multi-species/multifishery yield-per-recruit models were not capable of defining FsB(x) TRPs, a new multispecies/ multi-fishery spawner-biomass-per-recruit approach was developed. This approach allowed for the simulation of the response of spawner biomass-per-recruit to changes in effort in the three fishery sectors, simultaneously. The models showed that the spawner biomass-per-recruit, at current effort levels, was higher than the suggested TRP for the three species. However, it was shown that an increase of 10% in current total effort would reduce spawner biomass-per-recruit to below the recommended TRP levels. With the closure of the seine-net fishery, gill-net effort could be increased to 338 fishers (340 for management purposes) and effort in the hook-and-line fishery could be increased by 30% before the TRP was reached. To maintain the fish stocks above TRP levels, effort control was considered to be the most effective management method. The main recommendations for Lake Chicamba were to close the seine-net fishery, to limit the gill-net fishery to 340 fishers (using 137-m long x 3-m deep gill nets) and to maintain the open access nature of the hook-and-line fishery. The multi-species/multi-fishery per-recruit approach allows for the meaningful simulation of various scenarios and provides relatively robust management options. In the absence of long time series of effort and age- or length-based catch data, this approach was considered as the most suitable assessment method for multi-species/multi-gear African reservoir fisheries.
- Full Text:
- Date Issued: 1999
Structural studies on some enterobacterial capsular antigens
- Authors: Whittaker, Darryl Vanstone
- Date: 1994
- Subjects: Bacterial antigens -- Analysis Antigens Enterobacteriaceae Escherichia coli Klebsiella
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3803 , http://hdl.handle.net/10962/d1003281
- Description: The investigations presented in this thesis form part of a systematic international effort to establish the structures of the capsules produced by the bacterial genera, Escherichia coli and Klebsiella (family enterobacteriaceae). These bacteria are of medical interest as they are opportunistic pathogens and are frequently responsible for serious infections in animals and man. Invasive strains are invariably surrounded by a structurally complex polysaccharide capsule which contributes to the organism's ability to attenuate non-specific host defence mechanisms or, in some instances, to completely prevent an immune response. A knowledge of the chemical composition and structure of the capsule is, therefore, of great value as it provides insight into the mechanisms involved in this process. The E. coli, in particular, have generated considerable interest as their capsules are more structurally diverse and cross-reactivity with other, more pathogenic bacteria has also been demonstrated. Accordingly, the structures of three previously unstudied E. coli K-antigens viz. those produced by serotypes 020:K83:H26, 020:K84:H26, and 09:K48:H9 have been established by chemical and spectroscopic means and are presented in this thesis. In addition, a reinvestigation of the structure of the capsule produced by Klebsiella K15 using a novel enzymatic approach was also undertaken and a revised structure is proposed . The E. coli K48 polysaccharide is of special interest as it was found to contain a new diacetamido trideoxy hexose hitherto unrecorded. A synthesis for this saccharide is also presented. Finally, the application of lithium dissolved in ethylenediamine for the degradation of amino sugar-containing polysaccharides was also investigated using the capsular polysaccharides produced by E. coli serotypes K38 and K84 as model compounds.
- Full Text:
- Date Issued: 1994
Transformation in late colonial Ngqika society : a political, economic and social history of African communities in the district of Stutterheim (Eastern Cape), c.1870-1910
- Authors: Wotshela, L E
- Date: 1994
- Subjects: Xhosa (African people) -- History -- 19th century , Stutterheim (South Africa) -- History , Eastern Cape (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2574 , http://hdl.handle.net/10962/d1002427
- Description: This study analyses the methods and policies of the colonial government which shaped Stutterheim's African communities between c.1870 and 1910. In 1870 the Stutterheim magisterial district had not yet been officially established. However, creation of the British Kaffrarian administration (1847-1865) had already ensured the entrenchment of colonial rule over the humiliated Xhosa chiefdoms west of the Kei. This work studies transformations in late colonial Ngqika society and the development of Stutterheim as a magisterial district. It analyses the entrenchment of colonial bureaucracy and changes in indigenous social, economic and political structures. In the period c.1860-1877, direct administration of the Ngqika was first attempted. While recovering from the 1856-57 cattle killing, the Ngqika were brought under colonial administration by the annexation of British Kaffraria to the Cape Colony in 1865. The thesis also examines the process and implications of the breakup and resettlement of the Ngqika location after the 1877-1878 war and the mechanisms and complications in forming a new postwar settlement. The focus then narrows to Stutterheim magisterial district (finalised in 1880), where, after the removal of the main Ngqika population to the Transkei formal structures of quitrent settlement were established around mission stations. A new form of social behaviour underpinned by principles of individualism evolved under missionary influence. Urged on by legislation that sought to intensify implementation of individual tenure, this social behaviour predominated under the new administration. Attention is also given to the allocation of farm land in the district. On part of what had once been communally owned land, an immigrant farming community originally intended strictly for whites emerged. Numerous Africans later managed to hold property in this area. An urban area with a mixed African and white population resulted where allotments initially allocated to the German Legion were later auctioned. On crown lands, leasing and purchasing was initiated. By the early twentieth century, settlement patterns were in chaos: on the mission settlements, quitrenters disobeyed settlement regulations, farms were overpopulated by tenants and interracial urban settlements faced imminent segregationist policies. By 1910 local administration was in difficulties and the Africans were becoming politically mobilised against local and colonial policies.
- Full Text:
- Date Issued: 1994
A survey of the perceptions of lecturers and English Second Language students regarding ESL students' language-related problems at Technikon Natal
- Authors: Johnston, Graham Francis
- Date: 1993
- Subjects: English language -- Study and teaching -- South Africa -- Foreign speakers Compensatory education -- South Africa High school graduates -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1788 , http://hdl.handle.net/10962/d1003673
- Description: The shortage of manpower in South Africa with technological skills is a widespread problem. Technikons are under extreme pressure to develop these skills in the student population. Admission statistics at Technikon Natal show a marked increase in ESL students enrolling in a wide variety of national diploma courses. The inadequate education received by the majority of ESL students in South Africa has not prepared them for the demands of tertiary education. As English is the medium of instruction at Technikon Natal, underdeveloped language skills tend to hinder the students' progress. Technikon Natal is currently considering an Educational Development Strategy designed to assist students. In order for a response to perceived language-related problems to be meaningful, a survey of such issues was considered a practical starting point to establish that these issues were in fact problematic. The survey was intended to probe certain perceptions held by students and staff regarding attitudes, which might have been preconceived. It also provided clarification that some of these perceptions are inaccurate, and in some cases, incorrect. In addition to this, it established that there is considerable support among students and staff for departmentally-integrated support programmes. In terms of Technikon Natal's present position on an ESL educational development continuum, the findings indicate that much benefit could be derived from the research carried out in other tertiary institutions with regard to academic support programmes. Areas in which there was a considerable disparity of views held were identified and commented upon. In conclusion, it was felt that attention should be focussed on the following: recognition of the need for an integrated ESL programme; departmental reinforcement of academic skills; decentralisation of the ASP programme. The survey concludes with a brief comment on current developments in response to ESL needs at Technikon Natal.
- Full Text:
- Date Issued: 1993
An analysis of the influence exerted by the pharmacist and pharmacy assistant in the purchase decision of health and beauty aid products
- Authors: Suttner, Raymond Sharl
- Date: 1986
- Subjects: Cosmetics -- Marketing , Consumer behavior , Pharmacists -- Information services , Drugstores -- Marketing
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1189 , http://hdl.handle.net/10962/d1004383 , Cosmetics -- Marketing , Consumer behavior , Pharmacists -- Information services , Drugstores -- Marketing
- Description: [Introduction] The 1980s have ushered in an era of extreme competitive pressure for the modern business organisation. In previous times many business organisations have succeeded simply because of the excellence of their products, with little concern or attention being paid to the wants and needs of potential customers. As the business environment has become more competitive, however, the point of focus has changed. There is ample evidence which suggests a correlation between success in business and firms which have adopted a marketing-orientated philosophy of business. The evolution of marketing as a discipline has been hastened in recent times by the need of the firm to survive in the face of increasing competition. This "increasing attention" is occurring because of the realisation that sheer product excellence alone will not necessarily mean that the firm will succeed in establishing a group of satisfied customers in the long term. It is the adoption of the so-called "marketing concept" which provides the opportunity for the firm to develop a competitive edge which will more likely eventuate in success.
- Full Text:
- Date Issued: 1986
An investigation into the present system of orientation for pupils entering high school under the jurisdiction of the Cape Education Department, leading to an orientation programme
- Authors: Heath, John Lionel Potgieter
- Date: 1986
- Subjects: Education, Secondary -- South Africa Educational change -- South Africa Education and state -- South Africa Educational law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1870 , http://hdl.handle.net/10962/d1004769
- Full Text:
- Date Issued: 1986