A limited number of scientific publications dealing with aspects of BVDV infection have emanated from southern Africa. This study describes the isolation of BVD viruses, gene sequence analysis of the 5' non-translated region (5' NTR) of the genome, the generation of phylogenetic data of local strains and the recording of clinical signs associated with each isolate. Specimens (n=352) collected during 1998-1999, from live and dead animals from different farming systems, were obtained from private practitioners, feedlot consultants and abattoirs throughout the country. Specimens from buffaloes (cerus caffer the Kruger National Park were included as specimens from dead animals. Three cell lines and 200 tubes of pooled foetal bovine sera were also processed. Standard cell culture techniques to isolate virus were followed. Techniques designed to detect BVDV antigen or nucleic acid such as antigen capture enzyme-linked immunosorbent assay and polymerase chain reaction, were used on blood, organs and cell lines. The indirect fluorescent antibody test was used for antibody detection. Twenty-five isolates from cattle were confirmed as BVDV with PCR and after analysis of the 5'NTR, the most conserved part of the genome, a phylogenetic tree was constructed. All strains were noncytopathic and were identified as BVDV I, either BVDV Ia (NADL-like) or BVDV Ic or BVDV I* subgroups. BVDV was not detected in 37 lymph nodes obtained from 37 buffaloes in the Kruger National Park. Of the clinical signs in cattle from which virus was isolated, pyrexia and respiratory distress was the most frequent (46,7%), followed by pyrexia and diarrhoea (20%), respiratory disease without pyrexia (20%) and diarrhoea without pyrexia (13,3%). Abortion, congenital malformations, haemorrhagic syndrome and poor growth were also included as criteria for selection of animals for specimen collection. / Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2001. / Veterinary Tropical Diseases / unrestricted

More than 50% of hot metal production worldwide takes place in blast furnaces. Coke is the most expensive raw material in the blast furnace. It acts as the burden support as well as heat source and reductant in the blast furnace. As technology advances, supplementary fuels can supply heat and reduce the iron oxides, but coke would always be needed as burden support. Blast furnaces have been using coke for the past century and will continue to use coke for the next few decades. The price of coke is determined by its quality. Strict environmental laws and regulations in the USA pushed coke-making technology since the early 1990s towards the beehive type of oven. Gas collected during the coke cycle is used to supply heat to the process. The aim of this study is to investigate the spatial variation and coke quality in the non-recovery ovens and provide an explanation for it. The original coal was tested and samples of the coke were obtained from the top, bottom and sides of a coke oven. The samples were prepared and submitted for image analysis to determine the porosity, cell wall thickness and pore diameter. The samples were also submitted for a microscopical point counting to determine the micro textures of the coke. The coke was further submitted for the coke strength after reaction testing (CSR). The results show clear variation in the coke and a model of the behavior of the gas inside the coke oven during the carbonization process was developed based on the results of the tests. The model shows the flow of gas from the bottom of the oven up along the sidewalls to escape from the coke charge through the top. The flow of gas enriched the coke on the side of the oven by deposition of pyrolitic carbon to create an ultra-high grade of coke that could physically be separated from the rest of the coke and be sold separately at a higher price. / Dissertation (MSc (Geology))--University of Pretoria, 2007. / Geology / unrestricted

Parasitic helminths, mainly nematodes, are the most important causes of diseases of sheep and goats in the relatively warmer climatic areas of Ethiopia. This thesis comprises five related studies on the gastro-intestinal parasites namely, (1) the intensity of gastro-intestinal nematodes and coccidia in a semi-arid area, (2) the fluctuation of parasitic diseases in arid and semi-arid environments, (3) a questionnaire survey to study the perception of farmers and animal health workers on the control of worms by using anthelmintics and implications to the development of resistance, (4) a survey on the occurrence of anthelmintic resistance in selected areas and (5) the evaluation of the effectiveness of selective anthelmintic treatment using the FAMACHA / Thesis (PhD (Veterinary Science))--University of Pretoria, 2005. / Veterinary Tropical Diseases / unrestricted

The economy of West African countries is dependent mainly on agriculture. Livestock production is a vital source of providing dietary protein for the rapidly growing human population and it is therefore important to define strategies for controlling infectious diseases that are undermining the livestock industry. Although the foot-and-mouth disease (FMD) virus causes one of the most devastating economical diseases, it has been mainly ignored in West Africa due to low mortality rates in the face of other diseases that cause significant mortalities. This may explain the lack of interest for studying FMD infections in the region. However, the eradication of other diseases such as Rinderpest together with an increase in the number of outbreaks of FMD in recent years has caused a renewed interest in understanding the epidemiology of the disease. Foot-and-mouth disease is a highly contagious disease of cloven-hoofed animals. The causative agent, FMD virus, has a high rate of genetic variation in its single-stranded RNA genome. The genetic characterization of the surface capsid protein gene, VP1, is the most informative technique for studying the molecular epidemiology of FMD. The genetic profile of different serotypes of FMDV isolated across West Africa was investigated in this study using manual and automated nucleotide sequencing. A total number of 21 type O isolates from Ghana, Burkina Faso and South Africa (1992-2000), 23 SAT-1 viruses from Niger and Nigeria (1975-1981) and 30 SAT-2 viruses from Mali, Ivory Coast, Ghana, Nigeria, Liberia, Senegal and Gambia (1974-1991) were investigated. The sequence data was used to establish the phylogenetic relationships between the west African strains and those previously characterized from East, central and southern Africa as well as other regions of the world in the case of serotype O. Viruses from West Africa formed a single genotype while the isolates from South Africa clustered with the Pan-Asian topotype (Bangladesh 1997&Japan 2000). Sequence identity of 99 % and 95 % were found between Ghana-Burkina Faso and South Africa-Bangladesh type O viruses, respectively. Within SAT-2, the viruses characterized were isolated over 27 years from seven countries in West Africa and two indigenous topotypes (> 97 % sequence identity in the cluster) were identified. Of interest was the clustering of viruses Nigeria from 1982 and Eritrea in 1998, which has provided the first evidence of virus transmission between West and East Africa. For SAT-1, two distinct lineages (I-II) were identified. Lineage I consisted of viruses isolated between 1975-1976 from neighboring countries Niger and Nigeria, while lineage II was composed of viruses recovered from outbreaks between 1979-1981 in Nigeria. Furthermore, viruses from the latter lineage shared > 98 % sequence identity across the VP1 gene providing a clear indication of a long circulation of virus in the field in West Africa. For the serotypes investigated in this study viz. serotypes O, SAT-2 and SAT-1, it was shown that the year of isolation is more important in the epidemiology of FMD in West Africa than country of origin. The phylogenetic analysis demonstrated that viruses from each serotype grouped according to year of isolation rather than their geographical origin. This is in contrast of what was reported previously for FMDV strains in southern Africa. Results further revealed that FMD viruses from West Africa are evolving independently from viruses elsewhere on the continent and clustered in discrete genotypes. The genetic distinctiveness of west African FMD isolates is likely to be reflected antigenically and has implications in the selection of regionally appropriate field strains for use in vaccines to assist in the control of the disease. / Thesis (PhD (Veterinary Tropical Diseases))--University of Pretoria, 2002. / Veterinary Tropical Diseases / unrestricted

Anthrax is endemic in Luangwa National Park and the adjoining Game Management areas. The first official case of the disease was reported in 1922 in Luambe National Park. In 1987 a large-scale anthrax epidemic ravaged almost the entire Luangwa Valley. Since then at least three epidemics of the disease have been reported. Localised sporadic cases of the disease occur almost annually. Despite the frequent epidemics little is known of anthrax in terms of its epidemiology and impact on conservation. Mortalities were not investigated as wildlife officials attributed the mortalities to natural factors, animal population densities were not estimated and a no systematic disease surveillance programme exists. The number of animals that have died of the disease is not known. Anthrax mortalities are estimated in thousands. For example it is estimated that 4200 hippos and 1000 other animals, including five wild dogs, succumbed to the disease in 1987. No wild dog has been reported in the area since the 1987 epidemic. The objectives of this study were: # to describe the epidemiology and the socio-economic impact of anthrax in the Luangwa Valley ; # to examine the control measures adopted when epidemics occur; # to suggest alternative methods of dealing with disease outbreaks in the light of a quantitative risk and cost benefit analyses. Data was collected from reports was undertaken at the veterinary department, the wildlife offices and the national archives. Informal discussions were held with the local community on anthrax epidemics using the rapid rural appraisal technique. Data on animal demographics and rainfall were collected from National Parks and Wildlife Service and the National Meteorological Department. Soil, faeces, and bone samples were collected where large numbers of carcasses had been found during epidemics in the Luangwa National Park. These samples were examined for viable anthrax spores by the Department of Scientific Services in the Kruger National Park, South Africa. Information gleaned from official and verbal reports were collated and are presented in tabular from. The information found is inadequate to enable comprehensive quantitative risk and cost/benefit analyses. The economic cost of the disease arises mainly from the trade embargo resulting from veterinary quarantine regulations and the value of animal carcasses. Different scenarios were developed and are examined to present a risk analysis for proposed alternative control measures that could be adopted by the veterinary department when anthrax occurs in the Luangwa Valley. The probability of spreading anthrax by allowing trade in game trophies after treatment with formalin is estimated to be 0.0003-0.5. Although the impact of the disease on the economic utilisation of wild herbivores and community based natural resource management in the area has never been investigated the potential cost of anthrax epidemics is significant. The estimated cost of anthrax epidemics, depending on the size, as a result of the current disease control strategy are 124,3 – 2079,5 million Zambian Kwacha. The proposed alternative disease control measures could decrease the cost to 43,5 – 852, 6 million Zambian Kwacha. It is suggested that various measures be adopted to enable a better understanding of the dynamics of anthrax in the Luangwa Valley. These include : # the establishment of a veterinary unit with in the park # improved surveillance and reporting of diseases # regular censuses and estimates of population densities within the Park # improved communication between the veterinary Department and the Wildlife Authority. / Dissertation (MSc (Veterinary Tropical Diseases))--University of Pretoria, 2003. / Veterinary Tropical Diseases / unrestricted

Radiotherapy for cancer produces prolonged testicular damage that is manifested by failure of spermatogenic recovery following treatment. It has thus become important to develop methods to induce the recovery of spermatogenesis, if fertility is to be restored in patients (De Vita et al., 1997). The importance of steroid hormones in the control of testicular function has lead to numerous studies being conducted on the use of these hormones as treatment to protect the testes from radiation damage (Desjardins and Ewing, 1993; Kurdoglu et al, 1994; Kangasniemi et al., 1996a; Shuttlesworth et al., 2000). x The aim of this study was to investigate the effects of low dose gamma irradiation on the rat testes and the use of testosterone to reverse damage to the testes resulting from radiation exposure. Sprague Dawley rats were subjected to irradiation doses of 3.5 and 6.0 Gy. The rats were treated with testosterone over 4 and 8 weeks. Analyses were carried out at three levels: histological, kinematic, and endocrine. Irradiation led to a dose dependent reduction in spermatogenic cell numbers. Percentage sperm motility was decreased, and two of the five measured kinematic parameters, curvilinear velocity and straight line velocity, were decreased. Luteinising hormone (LH) and follicle stimulating hormone (FSH) concentrations increased in a dose dependent manner, while testosterone concentration showed insignificant fluctuations. Following testosterone administration, spermatogenic cell numbers improved. LH concentrations were restored to almost control levels. Testosterone administered following exposure of the rat testes to low dose gamma irradiation led to the recovery of spermatogenesis. / Dissertation (MSc)--University of Pretoria, 2002. / Anatomy and Physiology / Unrestricted

Electrocardiographic (ECG) changes have never been reported in canine babesiosis. Based on the metabolic, electrolyte, and myocardial alterations described for the disease, such changes are to be expected. The purpose of this study was to describe ECG changes in canine babesiosis, and to correlate those changes to clinical severity, outcome and cardiac histopathological changes. Four groups of dogs with babesiosis were studied: mild to moderate anaemia (n=40), severe anaemia (n=35), concurrent immune-mediated haemolytic anaemia (n=18) and complicated (n=28). Lead II ECG was recorded at admission for 1 minute in all dogs, and repeated after 24 hours in admitted dogs (groups II – IV). Six lead ECG was recorded in 88 dogs. Full necropsy was performed between 30-60 minutes after death on 16 dogs (5 died on arrival, 11 had ECG recording). Gross cardiac pathology was recorded and histopathology of myocardial sections from ventricles, atria, apex and interventricular septa was evaluated, using a scoring system for haemorrhages, necrosis, inflammatory infiltrate and fibrin microthrombi. The following ECG changes were recorded: sinoatrial (7%) and atrioventricular blocks (4%), ventricular premature complexes (7%), low R-amplitude (23%), prominent Q (33%), axis deviations (40%), prolonged QRS (32%), ST depression and coving (28%), large T (42%), and notched R (28%). Differences between groups were minor and inconsistent. Gross pathological changes were pericardial effusion (25%) and subepicardial (56%) and subendocardial haemorrhages (63%). Histological changes were haemorrhages (69%), necrosis (50%), inflammation (63%) and fibrin microthrombi (75%). The only correlation between pathology and ECG was low R-amplitude and pericardial effusion. There was a significantly higher prevalence of sinus bradycardia and irregular sinus rhythm in the non-survivors. Both ECG and pathological changes were non-specific, but there were similarities to the pattern of changes that have been described for myocarditis and myocardial ischaemia. Antiarrhythmic treatment was only required in 1 dog. Thus, the clinical application of the ECG changes found in this study was limited. It was concluded that the heart suffers from the same pathological processes described in other organs in canine babesiosis, namely inflammation and hypoxia. Cardiovascular management, if necessary, should be based on functional monitoring rather than ECG. / Dissertation (MMedVet (Med))--University of Pretoria, 2001. / Companion Animal Clinical Studies / unrestricted

The NPO sector has become a dominant economic force all over the world. With a base of more than 100 000 NPOs in South Africa, this sector, also known as the third sector, has become a force with which all in South Africa need to reckon. The size of the sector alone is an indication of the critically important role it plays in the development sector in our country. I have been working in the non-profit sector for more than 25 years. With this experience as background, my opinion is that the effect of the exponential growth of the sector is that NPOs are now sharing the market with for-profit corporations and public agencies. In almost all markets, NPOs face increasing competition – competition that has intensified the pressure these organisations face to find effective management methods. For survival and self-sustainability, it is imperative for NPOs to adopt the managerial techniques and systems of the for-profit corporations. It is my view that the implementation and management of corporate branding can contribute positively to improve communications and relationships with the internal and external audiences of NPOs in the same way as for-profit organisations. To prove this viewpoint I decided to use a case study focus to allow me to analyse the content of the corporate communication strategy of the Girl Guides Association of South Africa (GGASA) as a non-profit organisation. Following this approach, I endeavoured to establish the role which branding is playing in the organisation and how it can market itself to its internal and external audiences by using the organisation’s corporate brand. Three data collection methods were used, namely, document analysis semi-structured interviews and focus groups. Based on the above, the main research question for this study has been formulated as: “How can the GGASA develop/manage its corporate brand to communicate its image effectively to internal and external audiences?” Four sub-questions were formulated, focussing specifically on: the aims of the communication of the corporate branding; identity and image programme of the GGASA; the principles on which the communication of the corporate branding, identity and image programme of GGASA are based; the characteristics of the communication of the corporate branding, identity and image programme of the GGASA and what the perceptions of the internal and external audience are of the communication of the corporate branding, identity and image programme of the GGASA. In an attempt to answer this research question I endeavoured to link three theories, namely corporate communication, social marketing and branding in order to describe their integration within the NPO sector. By following this approach, a case can be made out that social marketing and corporate communication in the NPO sector is just as important as the organisation’s core service delivery business. Secondly, if an NPO is not sure what its brand is all about, such an organisation would be unable to implement any effective social marketing and/or strategic corporate communication, bearing in mind that the brand is the core and essence of an NPO and the pivot of all these actions. I am of the opinion that should the key recommendations of this study be put in place by the management of the GGASA, it will improve the implementation of its corporate communication, more specifically the corporate identity, image and brand management processes. This will in turn lead to an improvement in the effectiveness of the organisation’s communication and the achievement of its developmental objectives, which will enable them to position themselves as one of the new superbrands in South Africa, with real power to act on behalf of a perceived common good. In my opinion, the inclusion of recommendations provided by the GGASA target audiences during the field research enriched my own conclusions and recommendations. The recommendations were further formulated in such a way, that they could form the basis of a workable implementation plan for the management of the GGASA. This factor further enhances the value of the study. / Dissertation (MA (Development Communication))--University of Pretoria, 2005. / Information Science / unrestricted

Lumpy skin disease (LSD), affecting cattle in Africa, Madagascar and the Middle East, is caused by a capripox virus that belongs to the family Poxviridae. The disease is of economical importance in endemic areas and the Office International des Epizooties classifies it as a “List A”- disease. Effective control of LSD requires accurate and rapid laboratory techniques to confirm a tentative clinical diagnosis. Comparative studies on different diagnostic tests used at different stages of the disease have not been done. The aim of this study was to compare the different tests that are available and to provide data to assist in the selection of a rapid and sensitive laboratory test for the diagnosis of LSD. Six seronegative, prepubertal bulls were infected via the intravenous route and kept in an insect-free facility. The course of infection was monitored. During a three months’ period blood and semen samples were collected for virus isolation and polymerase chain reaction (PCR), and skin biopsies for the PCR, virus isolation, transmission electron microscopy (TEM), histopathological examination and immunoperoxidase staining of tissue sections. Antibody titres were assessed using the serum virus neutralization test (SNT) and indirect immunofluorescence test (IFAT). The incubation period in infected animals varied from 4 to 5 days. The length of viraemia did not correlate with the severity of clinical disease. By using virus isolation the duration of viraemia was determined to be from 1 to 12 days and by PCR from 4 to 11 days, which is longer than has previously been stated. Virus was isolated from semen until day 43 post-infection (p.i.) whereas the PCR could detect LSD virus nucleic acid until day 161 p.i. Virus was isolated from skin biopsies until day 39 p.i. and PCR could demonstrate viral DNA in them until day 92 p.i. The PCR was a fast and sensitive method to demonstrate viral DNA in blood, skin and semen samples. It could detect viral nucleic acid for significantly longer periods than any of the conventional methods. Virus isolation from blood, skin and semen samples was sensitive and reliable, but as a single test it may be too time-consuming although this depends how rapidly the diagnosis must be confirmed. The IFAT can be used for rapid confirmation of a clinical diagnosis but it needs careful standardization due to non-specific staining. The SNT showed positive results later in the course of the clinical disease than IFAT but it was however, sensitive and reliable in detecting antibodies from all the animals in this experiment. Transmission electron microscopy of skin biopsies detected LSD virus only in one of the four bulls that developed skin lesions. This indicated that even though TEM is usually considered to be a fast and reliable method, a negative result must still be confirmed using another method. Histopathological changes of the skin lesions in sections stained with haematoxylin and eosin were typical for the disease. It was not possible to make a reliable diagnosis of LSD based only on immunoperoxidase staining of tissue sections. In conclusion, this study indicated the PCR to be superior in detecting LSD virus from blood, skin and semen samples. However, virus isolation is still required when the infectivity of the LSD virus is to be investigated. Even though the IFAT has been used for several decades, it is still a valuable tool in detecting antibodies against LSD virus. Both the SNT and IFAT are useful and reliable in retrospective, epidemiological studies. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2004. / Veterinary Tropical Diseases / unrestricted

The main purpose of this work was to develop rapid and reliable techniques that will prove valuable in epidemiological studies of equine encephalosis virus (EEV), the detection and identification of the virus for the laboratory confirmation of the clinical diagnosis and for the differential diagnosis between EEV and African horsesickness virus (AHSV). Two enzyme linked immunosorbent assays (ELISA) were developed. A polyclonal antibody-based, group-specific, indirect sandwich ELISA for the detection of EEV antigen was developed. The design of the assay was based on the methods currently used for the detection of AHSV. The cut-off value (absorbance of 0.15) was determined using populations of known negative specimens. No cross-reactions were recorded with viruses from other orbivirus serogroups or from other arboviruses. The assay proved to be sensitive and specific for the rapid detection of EEV and viral antigens in cell culture and mouse brain preparations. A polyclonal antibody-based, group-specific, competitive ELISA for the detection of antibodies to EEV was developed. No cross-reactions were recorded with the reference sera prepared against other orbivirus serogroups or other arboviruses. The cut-off (29.5% inhibition) value was determined using populations of known positive and negative sera. Analysis of the data showed the assay to be highly repeatable, sensitive and specific. / Dissertation (MSc (Veterinary Science))--University of Pretoria, 2001. / Veterinary Tropical Diseases / unrestricted