Digestible energy as a criterion for the development of diets for the African sharptooth catfish, Clarias gariepinus (Pisces: Clariidae)
- Authors: Rouhani, Q A
- Date: 1993
- Subjects: Clariidae , Catfishes -- Africa , Catfishes -- Nutrition -- Requirements -- Africa , Catfishes , Clarias
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5259 , http://hdl.handle.net/10962/d1005103
- Description: Based on a number of attributes, the African sharptooth catfish, Clarias gariepinus is an ideal aquaculture species. Much work has been undertaken on developing the technology for the commercial culture of the species inclusive of determining the nutritional requirements for cost effective feed formulation. However, digestible energy (DE) values for specific feed ingredients were unknown. As DE values are not interchangeable between species, this study set out to determine the DE values for conventional and unconventional feed-ingredients for the formulation of an optimal feed. The ultimate goal in feed formulation is to produce a diet that supports the maximum production at the least cost. The indirect method was found to be most suitable in obtaining DE values for the catfish. Feed samples were marked by adding 2% chromic oxide as an inert indicator. The fish were then force-fed and faecal samples were obtained from the hindgut by stripping the fish 10 hours after feeding as this was found to be when the hind-gut was at its fullest and the feed maximally digested. A linear based computer programme was used to formulate experimental diets using the established DE values as an additional variable. The formulated feed was tested and compared to a commercial catfish diet and a standard reference diet (H-440). All of the newly formulated feeds were found to be cheaper to manufacture (by between 5 and 10%). Statistically (ANOVA), all of the experimental diets resulted in higher specific growth rates (SGR) than the standard reference diet. The commercial diet also resulted in a lower SGR than those experimental diets with similar protein levels.
- Full Text:
- Date Issued: 1993
- Authors: Rouhani, Q A
- Date: 1993
- Subjects: Clariidae , Catfishes -- Africa , Catfishes -- Nutrition -- Requirements -- Africa , Catfishes , Clarias
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5259 , http://hdl.handle.net/10962/d1005103
- Description: Based on a number of attributes, the African sharptooth catfish, Clarias gariepinus is an ideal aquaculture species. Much work has been undertaken on developing the technology for the commercial culture of the species inclusive of determining the nutritional requirements for cost effective feed formulation. However, digestible energy (DE) values for specific feed ingredients were unknown. As DE values are not interchangeable between species, this study set out to determine the DE values for conventional and unconventional feed-ingredients for the formulation of an optimal feed. The ultimate goal in feed formulation is to produce a diet that supports the maximum production at the least cost. The indirect method was found to be most suitable in obtaining DE values for the catfish. Feed samples were marked by adding 2% chromic oxide as an inert indicator. The fish were then force-fed and faecal samples were obtained from the hindgut by stripping the fish 10 hours after feeding as this was found to be when the hind-gut was at its fullest and the feed maximally digested. A linear based computer programme was used to formulate experimental diets using the established DE values as an additional variable. The formulated feed was tested and compared to a commercial catfish diet and a standard reference diet (H-440). All of the newly formulated feeds were found to be cheaper to manufacture (by between 5 and 10%). Statistically (ANOVA), all of the experimental diets resulted in higher specific growth rates (SGR) than the standard reference diet. The commercial diet also resulted in a lower SGR than those experimental diets with similar protein levels.
- Full Text:
- Date Issued: 1993
Ecology and natural history of the Masarid wasps of the world with an assessment of their role as pollinators in southern Africa (Hymenoptera : Vespoidea : Masaridae)
- Authors: Gess, Sarah Kathleen
- Date: 1993
- Subjects: Wasps -- Ecology Pollen wasps -- Ecology Vespidae -- Ecology Pollination by insects -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5669 , http://hdl.handle.net/10962/d1005354
- Description: The worldwide knowledge of the ecology and natural history of the masarid wasps, those wasps which bee-like provision their nest cells with pollen and nectar, is synthesized and discussed putting into context the investigations concerning nesting and flower visiting by southern African masarids conducted by the present author. Masarids are found mostly to favour warm to hot areas with relatively low rainfall and open scrubby vegetation. At the generic level the masarids of the Nearctic, Neotropical and Australian regions are distinct from each other and from those of the Palaearctic and Afrotropical regions combined. No species are shared between regions. Southern Africa is apparently the area of greatest species diversity. In this region, at least, there is a high incidence of narrow endemism. Masarids are associated with a relatively small range of plant families. Where sufficient records are available distinct major preferences are shown between zoogeographical regions. Relatedness of plant preferences between zoogeographical regions is apparent when relatedness of plant taxa is considered. Within a region there is marked overlap in masarid generic preferences for flower families. At the specific level there is marked oligolecty and narrow polylecty. The majority of nesting studies indicate that nest construction, egg laying and provisioning are performed by a single female per nest, however, nest sharing has been alledged for two species. No parasitic masarids have been recorded. Egg laying precedes provisioning. Mass provisioning is the rule. According to species, nests are sited in the ground, in non-friable soil or friable soil, in earthen vertical banks, on stones or on plants. Seven nest types are defined. Three bonding agents, water, nectar and self-generated silk are used. Masarids are evaluated as potential pollinators of their forage plants in southern Africa. The "masarid pollination syndrome", though less broad is shown to fall within that designated melittophily. The case studies considered make it clear that, whereas the masarids visiting some flower groups are members of a guild of potential pollinators, the masarids visiting others are probably their most important pollinators. Increasing land utilization is shown to threaten the existence of narrowly endmic masarid species.
- Full Text:
- Date Issued: 1993
- Authors: Gess, Sarah Kathleen
- Date: 1993
- Subjects: Wasps -- Ecology Pollen wasps -- Ecology Vespidae -- Ecology Pollination by insects -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5669 , http://hdl.handle.net/10962/d1005354
- Description: The worldwide knowledge of the ecology and natural history of the masarid wasps, those wasps which bee-like provision their nest cells with pollen and nectar, is synthesized and discussed putting into context the investigations concerning nesting and flower visiting by southern African masarids conducted by the present author. Masarids are found mostly to favour warm to hot areas with relatively low rainfall and open scrubby vegetation. At the generic level the masarids of the Nearctic, Neotropical and Australian regions are distinct from each other and from those of the Palaearctic and Afrotropical regions combined. No species are shared between regions. Southern Africa is apparently the area of greatest species diversity. In this region, at least, there is a high incidence of narrow endemism. Masarids are associated with a relatively small range of plant families. Where sufficient records are available distinct major preferences are shown between zoogeographical regions. Relatedness of plant preferences between zoogeographical regions is apparent when relatedness of plant taxa is considered. Within a region there is marked overlap in masarid generic preferences for flower families. At the specific level there is marked oligolecty and narrow polylecty. The majority of nesting studies indicate that nest construction, egg laying and provisioning are performed by a single female per nest, however, nest sharing has been alledged for two species. No parasitic masarids have been recorded. Egg laying precedes provisioning. Mass provisioning is the rule. According to species, nests are sited in the ground, in non-friable soil or friable soil, in earthen vertical banks, on stones or on plants. Seven nest types are defined. Three bonding agents, water, nectar and self-generated silk are used. Masarids are evaluated as potential pollinators of their forage plants in southern Africa. The "masarid pollination syndrome", though less broad is shown to fall within that designated melittophily. The case studies considered make it clear that, whereas the masarids visiting some flower groups are members of a guild of potential pollinators, the masarids visiting others are probably their most important pollinators. Increasing land utilization is shown to threaten the existence of narrowly endmic masarid species.
- Full Text:
- Date Issued: 1993
Election Programme for COSATU
- COSATU
- Authors: COSATU
- Date: July 1993
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/113977 , vital:33865
- Description: COSATU must intervene in affiliates where it has identified problems, where problems have been brought to its attention and / or has been requested to do so. The CEC should draw guidelines on how and under which circumstances the federation and its structures may intervene taking into account clauses 3.9 and 3.10 of the constitution. Such intervention should not undermine affiliates where such problems exist. COSATU leadership must be visible during major disputes between affiliates and employers and co-ordinate solidarity with workers involved in such disputes.
- Full Text:
- Date Issued: July 1993
- Authors: COSATU
- Date: July 1993
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/113977 , vital:33865
- Description: COSATU must intervene in affiliates where it has identified problems, where problems have been brought to its attention and / or has been requested to do so. The CEC should draw guidelines on how and under which circumstances the federation and its structures may intervene taking into account clauses 3.9 and 3.10 of the constitution. Such intervention should not undermine affiliates where such problems exist. COSATU leadership must be visible during major disputes between affiliates and employers and co-ordinate solidarity with workers involved in such disputes.
- Full Text:
- Date Issued: July 1993
English in South Africa : effective communication and the policy debate : inaugural lecture delivered at Rhodes University
- Authors: Wright, Laurence
- Date: 1993
- Subjects: Communication -- South Africa , English language -- South Africa , South Africa -- Politics and government -- 1993-1994
- Language: English
- Type: Text
- Identifier: vital:683 , http://hdl.handle.net/10962/d1020752 , ISBN 0620031557
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1993
- Authors: Wright, Laurence
- Date: 1993
- Subjects: Communication -- South Africa , English language -- South Africa , South Africa -- Politics and government -- 1993-1994
- Language: English
- Type: Text
- Identifier: vital:683 , http://hdl.handle.net/10962/d1020752 , ISBN 0620031557
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1993
Epidemiological and aetiological aspects of diarrhoeal disease in the Eastern Cape
- Authors: Baxter, Esther
- Date: 1993
- Subjects: Diarrhea -- South Africa , Intestines -- Diseases , Pathogenic microorganisms -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4045 , http://hdl.handle.net/10962/d1004106 , Diarrhea -- South Africa , Intestines -- Diseases , Pathogenic microorganisms -- South Africa
- Description: Diarrhoeal disease is a major cause of mortality in children in developing countries. It also remains a serious problem among all age groups throughout the world. Whereas studies to determine the epidemiological and aetiological factors of diarrhoeal disease have been reported for other parts of South Africa and the world, as yet no information is available for the Eastern Cape. Therefore this study was undertaken to determine the factors for this area. Enteropathogens were compared for the different ages in the various population groups and, where possible, seasonal and geographical differences were emphasised. A total of 7 278 faecal samples were examined by six laboratories in the Eastern Cape during the period November 1988 to October 1990. Data was recorded noting the age, sex and population group of the patients. The towns selected were Port Elizabeth, Uitenhage, Cradock, Grahamstown and their surrounding areas. The isolation rates for the pathogens studied in the various population groups were compared to those reported in similar studies in other countries. The seasonal incidences of the various selected pathogens were compared with those reported from elsewhere in South Africa. It was thought that the higher temperature of summer may influence the finding in the White population group, while rainfall would play a greater role for the Coloured and Black populations. The geographical distribution of the pathogens emphasised the difference in living conditions between the different population groups. For example a generally higher infestation rate of Helminths occurred in rural areas and in the groups living under poorer conditions. The low isolation rates for certain bacteria and the large percentage of samples from which no pathogens were isolated indicate the need for further research. However, the finding should be valuable for determining Public Health priorities and in the management of outbreaks of diarrhoeal disease.
- Full Text:
- Date Issued: 1993
- Authors: Baxter, Esther
- Date: 1993
- Subjects: Diarrhea -- South Africa , Intestines -- Diseases , Pathogenic microorganisms -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4045 , http://hdl.handle.net/10962/d1004106 , Diarrhea -- South Africa , Intestines -- Diseases , Pathogenic microorganisms -- South Africa
- Description: Diarrhoeal disease is a major cause of mortality in children in developing countries. It also remains a serious problem among all age groups throughout the world. Whereas studies to determine the epidemiological and aetiological factors of diarrhoeal disease have been reported for other parts of South Africa and the world, as yet no information is available for the Eastern Cape. Therefore this study was undertaken to determine the factors for this area. Enteropathogens were compared for the different ages in the various population groups and, where possible, seasonal and geographical differences were emphasised. A total of 7 278 faecal samples were examined by six laboratories in the Eastern Cape during the period November 1988 to October 1990. Data was recorded noting the age, sex and population group of the patients. The towns selected were Port Elizabeth, Uitenhage, Cradock, Grahamstown and their surrounding areas. The isolation rates for the pathogens studied in the various population groups were compared to those reported in similar studies in other countries. The seasonal incidences of the various selected pathogens were compared with those reported from elsewhere in South Africa. It was thought that the higher temperature of summer may influence the finding in the White population group, while rainfall would play a greater role for the Coloured and Black populations. The geographical distribution of the pathogens emphasised the difference in living conditions between the different population groups. For example a generally higher infestation rate of Helminths occurred in rural areas and in the groups living under poorer conditions. The low isolation rates for certain bacteria and the large percentage of samples from which no pathogens were isolated indicate the need for further research. However, the finding should be valuable for determining Public Health priorities and in the management of outbreaks of diarrhoeal disease.
- Full Text:
- Date Issued: 1993
Evaluation of environmental education courses in Bophuthatswana colleges of education
- Authors: Leketi, Makgau Peter
- Date: 1993
- Subjects: Environmental education -- South Africa -- Bophuthatswana Environmental education -- Study and teaching -- South Africa -- Bophuthatswana Environmental education -- Curricula -- South Africa -- Bophuthatswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1525 , http://hdl.handle.net/10962/d1003407
- Description: This study evaluates Environmental Education courses in Bophuthatswana Colleges of Education. The semi-structured interviews with final year students, lecturers, rectors of colleges offering the courses, external examiners and the course co-ordinator at the Institute of Education at the University of Bophuthatswana (Unibo) are made. Written documents relating to Environmental Education courses, such as students' examination answer books, moderators' reports and minutes of meetings, are also used to evaluate the courses. Specifically, the aim of this study is to identify the strengths and the weaknesses of Environmental Education courses in Bophuthatswana Colleges of Education and this would present a contribution in the research field and also be useful in the further refinement of the courses. Strengths and weaknesses identified in this research are related to knowledge of Environmental Education and environmental issues, the syllabuses of the Environmental Education courses, the operation of the courses, the examining of the courses and the ethos and support of the colleges and the local university's Institute of Education. New insights are gained inter alia into the operation of Environmental Education courses in the Teacher Education programme in Bophuthatswana. An important contribution of the study is the application of the phenomenological paradigm, since it allows understanding of subjective experience as far as the operation of Environmental Education is concerned.
- Full Text:
- Date Issued: 1993
- Authors: Leketi, Makgau Peter
- Date: 1993
- Subjects: Environmental education -- South Africa -- Bophuthatswana Environmental education -- Study and teaching -- South Africa -- Bophuthatswana Environmental education -- Curricula -- South Africa -- Bophuthatswana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1525 , http://hdl.handle.net/10962/d1003407
- Description: This study evaluates Environmental Education courses in Bophuthatswana Colleges of Education. The semi-structured interviews with final year students, lecturers, rectors of colleges offering the courses, external examiners and the course co-ordinator at the Institute of Education at the University of Bophuthatswana (Unibo) are made. Written documents relating to Environmental Education courses, such as students' examination answer books, moderators' reports and minutes of meetings, are also used to evaluate the courses. Specifically, the aim of this study is to identify the strengths and the weaknesses of Environmental Education courses in Bophuthatswana Colleges of Education and this would present a contribution in the research field and also be useful in the further refinement of the courses. Strengths and weaknesses identified in this research are related to knowledge of Environmental Education and environmental issues, the syllabuses of the Environmental Education courses, the operation of the courses, the examining of the courses and the ethos and support of the colleges and the local university's Institute of Education. New insights are gained inter alia into the operation of Environmental Education courses in the Teacher Education programme in Bophuthatswana. An important contribution of the study is the application of the phenomenological paradigm, since it allows understanding of subjective experience as far as the operation of Environmental Education is concerned.
- Full Text:
- Date Issued: 1993
First Democratic Elections
- NUMSA
- Authors: NUMSA
- Date: 1993
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110159 , vital:33238
- Description: Every member is free to join any political party. NUMSA will encourage its members to vote ANC because it wants a strong government to fix up the country's and workers' problems. NUMSA members must not force anyone to vote for the ANC or any other party. NUMSA members must be free to vote (or not vote) for whoever they want. It is your right to vote; it is also your right not to vote. BUT you may not force anyone to vote or not vote. Voting stations will be in places like schools, community halls. Ask and discuss with your fellow workers, ask at NUMSA or COSATU offices, listen to your radio, look for posters and pamphlets nearer election time to find out.
- Full Text:
- Date Issued: 1993
- Authors: NUMSA
- Date: 1993
- Subjects: NUMSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110159 , vital:33238
- Description: Every member is free to join any political party. NUMSA will encourage its members to vote ANC because it wants a strong government to fix up the country's and workers' problems. NUMSA members must not force anyone to vote for the ANC or any other party. NUMSA members must be free to vote (or not vote) for whoever they want. It is your right to vote; it is also your right not to vote. BUT you may not force anyone to vote or not vote. Voting stations will be in places like schools, community halls. Ask and discuss with your fellow workers, ask at NUMSA or COSATU offices, listen to your radio, look for posters and pamphlets nearer election time to find out.
- Full Text:
- Date Issued: 1993
Foreign indirect investment platform
- ANC
- Authors: ANC
- Date: 1993
- Subjects: ANC
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/153901 , vital:39535
- Description: In the transition from apartheid to democracy, strong economic growth will be needed. This growth must succeed in overcoming the handicaps which apartheid imposed on South Africa. And it must bring higher living standards to the black majority, a reduction in absolute poverty levels, and a more equitable distribution of resources. The key to sustained and balanced economic growth is investment. Investment in productive capital must be greatly increased, and soon.
- Full Text:
- Date Issued: 1993
- Authors: ANC
- Date: 1993
- Subjects: ANC
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/153901 , vital:39535
- Description: In the transition from apartheid to democracy, strong economic growth will be needed. This growth must succeed in overcoming the handicaps which apartheid imposed on South Africa. And it must bring higher living standards to the black majority, a reduction in absolute poverty levels, and a more equitable distribution of resources. The key to sustained and balanced economic growth is investment. Investment in productive capital must be greatly increased, and soon.
- Full Text:
- Date Issued: 1993
Forward to one education department
- SADTU
- Authors: SADTU
- Date: 1993
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/155115 , vital:39856
- Description: As the elected minute secretary, from the Second AGC 1992, I took over the portfolio as acting Regional Secretary when Mundisa Sinuka resigned in October 1992. In SADTU, we can only have a successful union if all our branches are functioning effectively and our members are committed. Members on the ground have been demotivated and this makes our task all the more difficult. Branches tend to work during times of crisis and it should be borne in mind that SADTU is not a crisis union but is there to educate, bur id. protect and defend the rights of teachers.
- Full Text:
- Date Issued: 1993
- Authors: SADTU
- Date: 1993
- Subjects: SADTU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/155115 , vital:39856
- Description: As the elected minute secretary, from the Second AGC 1992, I took over the portfolio as acting Regional Secretary when Mundisa Sinuka resigned in October 1992. In SADTU, we can only have a successful union if all our branches are functioning effectively and our members are committed. Members on the ground have been demotivated and this makes our task all the more difficult. Branches tend to work during times of crisis and it should be borne in mind that SADTU is not a crisis union but is there to educate, bur id. protect and defend the rights of teachers.
- Full Text:
- Date Issued: 1993
Gnouman Ke La
- Sali Sidibe (composition, lyrics, lead vocal), Boubacar Kane (djembe), Aminata Diabate, Fatim Sissoko (backing vocals), Rakesh Toure (keyboards), Mamadou Coulibaly (N'Bolon), Harouna Samake (N'goni), Zoumana Tereka (Violin), Samba Dioakite (Balafon), Sterns Africa label, Samassa Records
- Authors: Sali Sidibe (composition, lyrics, lead vocal) , Boubacar Kane (djembe) , Aminata Diabate, Fatim Sissoko (backing vocals) , Rakesh Toure (keyboards) , Mamadou Coulibaly (N'Bolon) , Harouna Samake (N'goni) , Zoumana Tereka (Violin) , Samba Dioakite (Balafon) , Sterns Africa label , Samassa Records
- Date: 1993
- Subjects: Popular music--Africa, West , Popular music--Mali--1991-2000 , Africa Mali Bamako f-ml
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130033 , vital:36366 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC36-05
- Description: Malian neo-traditional vocals set to a unique blend of didai, sigui and sogonikun dance rhythms
- Full Text: false
- Date Issued: 1993
- Authors: Sali Sidibe (composition, lyrics, lead vocal) , Boubacar Kane (djembe) , Aminata Diabate, Fatim Sissoko (backing vocals) , Rakesh Toure (keyboards) , Mamadou Coulibaly (N'Bolon) , Harouna Samake (N'goni) , Zoumana Tereka (Violin) , Samba Dioakite (Balafon) , Sterns Africa label , Samassa Records
- Date: 1993
- Subjects: Popular music--Africa, West , Popular music--Mali--1991-2000 , Africa Mali Bamako f-ml
- Language: Bambara
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/130033 , vital:36366 , International Library of African Music, Rhodes University, Grahamstown, South Africa , SDC36-05
- Description: Malian neo-traditional vocals set to a unique blend of didai, sigui and sogonikun dance rhythms
- Full Text: false
- Date Issued: 1993
Granitic series and their economic geology
- Authors: Kerber, Paulo Augusto
- Date: 1993
- Subjects: Granite , Geology, Economic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4969 , http://hdl.handle.net/10962/d1005581 , Granite , Geology, Economic
- Description: The granitic rocks are subdivided into four series: tholeiitic, alkaline, calc-alkaline and mobilizates. These series can be formed from melting of mantle material (M-type granites) or from crustal rocks. There are granitic rocks formed from the mixing of these two magmas types. The rocks formed from crustal anatexis are subdivided into those formed from igneous rocks (I-type granites) and those formed from meta-sedimentary rocks (S-type granites). The former has similar characteristics to the mantle-derived granitoids. The mineral deposits related to igneous or mantle derived magma usually are Cu-Au, CUI Cu-Mo, Mo porphyries and have high oxygen fugacity and magnetic susceptibility (magnetite series). The Sn-W deposits usually are related to magma derived from meta-sedimentary or igneous rocks derived magma with low oxygen fugacity and magnetic susceptibility (ilmenite series). According to the tectonic setting, the granitoids rocks are classified as: Andino type, West Pacific type, Hercyno type, Caledonian type and Anorogenic (A-type granites).
- Full Text:
- Date Issued: 1993
- Authors: Kerber, Paulo Augusto
- Date: 1993
- Subjects: Granite , Geology, Economic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4969 , http://hdl.handle.net/10962/d1005581 , Granite , Geology, Economic
- Description: The granitic rocks are subdivided into four series: tholeiitic, alkaline, calc-alkaline and mobilizates. These series can be formed from melting of mantle material (M-type granites) or from crustal rocks. There are granitic rocks formed from the mixing of these two magmas types. The rocks formed from crustal anatexis are subdivided into those formed from igneous rocks (I-type granites) and those formed from meta-sedimentary rocks (S-type granites). The former has similar characteristics to the mantle-derived granitoids. The mineral deposits related to igneous or mantle derived magma usually are Cu-Au, CUI Cu-Mo, Mo porphyries and have high oxygen fugacity and magnetic susceptibility (magnetite series). The Sn-W deposits usually are related to magma derived from meta-sedimentary or igneous rocks derived magma with low oxygen fugacity and magnetic susceptibility (ilmenite series). According to the tectonic setting, the granitoids rocks are classified as: Andino type, West Pacific type, Hercyno type, Caledonian type and Anorogenic (A-type granites).
- Full Text:
- Date Issued: 1993
History reading comprehension in black secondary schools : a Ciskei study
- Authors: Poswa, Mandisa
- Date: 1993
- Subjects: History -- Study and teaching (Secondary) -- South Africa -- Ciskei
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1555 , http://hdl.handle.net/10962/d1003437
- Description: This thesis examines briefly the problems of learning and understanding history when the subject is taught through the medium of a second language. It assesses the difficulty levels (for first language speakers) of the history textbooks commonly used in Ciskei secondary schools and considers the implications of these levels for second language speakers. It assesses the ability of 400 pupils in standard 8 and standard 10 to comprehend an English text which is deliberately written at a lower level of difficulty than that of the current secondary school texts. Comparisons are made of the comprehension scores of those pupils whose answers are written in English with those who are allowed to answer in Xhosa on questions based on the simple text. Finally, it compares the quality of the pupils' answers in Xhosa and English. Tentative recommendations are made about the language implications of history teaching which emerge from the results of the research.
- Full Text:
- Date Issued: 1993
- Authors: Poswa, Mandisa
- Date: 1993
- Subjects: History -- Study and teaching (Secondary) -- South Africa -- Ciskei
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1555 , http://hdl.handle.net/10962/d1003437
- Description: This thesis examines briefly the problems of learning and understanding history when the subject is taught through the medium of a second language. It assesses the difficulty levels (for first language speakers) of the history textbooks commonly used in Ciskei secondary schools and considers the implications of these levels for second language speakers. It assesses the ability of 400 pupils in standard 8 and standard 10 to comprehend an English text which is deliberately written at a lower level of difficulty than that of the current secondary school texts. Comparisons are made of the comprehension scores of those pupils whose answers are written in English with those who are allowed to answer in Xhosa on questions based on the simple text. Finally, it compares the quality of the pupils' answers in Xhosa and English. Tentative recommendations are made about the language implications of history teaching which emerge from the results of the research.
- Full Text:
- Date Issued: 1993
IEC CONFERENCE ON PROFIT SHARING
- NUM
- Authors: NUM
- Date: 1993
- Subjects: NUM
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/174134 , vital:42445
- Description: At present, profit sharing does not fit into the philosophy of any trade unions in South Africa. It is not a part of the policy of any union I know about. Where profit sharing schemes exist and are accepted by the unions, this is because of special circumstances. This talk is in three parts: First, I will explain where my union, the National Union of Mineworkers, has accepted profit sharing schemes and why it has done so. Secondly, I will outline the different levels of agreements that we have negotiated on profit sharing and the principles we have agreed should govern such schemes Thirdly, I will speak of the implementation of the schemes, and their potential for providing a basis for greater worker participation in the enterprises which have negotiated profit sharing agreements.
- Full Text:
- Date Issued: 1993
- Authors: NUM
- Date: 1993
- Subjects: NUM
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/174134 , vital:42445
- Description: At present, profit sharing does not fit into the philosophy of any trade unions in South Africa. It is not a part of the policy of any union I know about. Where profit sharing schemes exist and are accepted by the unions, this is because of special circumstances. This talk is in three parts: First, I will explain where my union, the National Union of Mineworkers, has accepted profit sharing schemes and why it has done so. Secondly, I will outline the different levels of agreements that we have negotiated on profit sharing and the principles we have agreed should govern such schemes Thirdly, I will speak of the implementation of the schemes, and their potential for providing a basis for greater worker participation in the enterprises which have negotiated profit sharing agreements.
- Full Text:
- Date Issued: 1993
Imbongi in Profile
- Authors: Kaschula, Russell H
- Date: 1993
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124689 , vital:35649 , https://www.jstor.org/stable/40238706
- Description: Today, many elements of the tradition have been discarded or adapted; nevertheless, the concept of singing praises still retains an identifiable character which is based on past tradition. In this tradition, the imbongi' s relationship with his audience and the function of his izibongo (poetry) within his society are of utmost importance. Any analysis of this communitarian art form will therefore have to take into account the context of the performance, the nature of the audience, and the role of the imbongi in a society which continues to be subject to socio-cultural and political pressures of unused intensity. My intention in this article is to provide a case study of Bongani Sitole, a contemporary imbongi, in order to instance some of the ways in which the tradition has adapted. During the course of the discussion mention will also be made of other iimbongi.
- Full Text:
- Date Issued: 1993
- Authors: Kaschula, Russell H
- Date: 1993
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124689 , vital:35649 , https://www.jstor.org/stable/40238706
- Description: Today, many elements of the tradition have been discarded or adapted; nevertheless, the concept of singing praises still retains an identifiable character which is based on past tradition. In this tradition, the imbongi' s relationship with his audience and the function of his izibongo (poetry) within his society are of utmost importance. Any analysis of this communitarian art form will therefore have to take into account the context of the performance, the nature of the audience, and the role of the imbongi in a society which continues to be subject to socio-cultural and political pressures of unused intensity. My intention in this article is to provide a case study of Bongani Sitole, a contemporary imbongi, in order to instance some of the ways in which the tradition has adapted. During the course of the discussion mention will also be made of other iimbongi.
- Full Text:
- Date Issued: 1993
Information systems and creative responses : inaugural lecture delivered at Rhodes University
- Authors: Sainsbury, Malcolm
- Date: 1993
- Subjects: Computer architecture , Information storage and retrieval systems , Computer engineering
- Language: English
- Type: Text
- Identifier: vital:663 , http://hdl.handle.net/10962/d1020732 , ISBN 0868102695
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1993
- Authors: Sainsbury, Malcolm
- Date: 1993
- Subjects: Computer architecture , Information storage and retrieval systems , Computer engineering
- Language: English
- Type: Text
- Identifier: vital:663 , http://hdl.handle.net/10962/d1020732 , ISBN 0868102695
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1993
Innovations in gold extraction
- Authors: Davidson, Raymond John
- Date: 1993
- Subjects: Gold -- Analysis -- Research Gold -- Metallurgy -- Research Gold mines and mining -- Research
- Language: English
- Type: Thesis , Doctoral , DSc
- Identifier: vital:4317 , http://hdl.handle.net/10962/d1004975
- Description: The thesis takes the form of a collection of publications and patents concerning gold extraction which were presented over a period of 18 years while employed at the Anglo American Research Laboratories.
- Full Text:
- Date Issued: 1993
- Authors: Davidson, Raymond John
- Date: 1993
- Subjects: Gold -- Analysis -- Research Gold -- Metallurgy -- Research Gold mines and mining -- Research
- Language: English
- Type: Thesis , Doctoral , DSc
- Identifier: vital:4317 , http://hdl.handle.net/10962/d1004975
- Description: The thesis takes the form of a collection of publications and patents concerning gold extraction which were presented over a period of 18 years while employed at the Anglo American Research Laboratories.
- Full Text:
- Date Issued: 1993
Interaction of cyanide with iron (II) phthalocyanine
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295497 , vital:57347 , xlink:href="https://doi.org/10.1039/DT9930003601"
- Description: The kinetics and equilibria for the reaction between cyanide and iron (II) phthalocyanine [Fe(pc)](H2pc = phthalocyanine) in dimethyl sulfoxide (dmso) were studied at 25 °C. The complex [Fe(pc)(CN)2]2– is formed in two consecutive pseudo-first-order processes with k2f= 17.5 ± 0.8 dm3 mol–1 s–1 and k3f= 0.20 ± 0.05 dm3 mol–1 s–1, where k2f and k3f are the rate constants for the binding of the first and second cyanide ligands, respectively. The equilbrium constants were fund to be K2= 3.0 × 103 dm3 mol–1 and K3= 5.7 × 102 dm3 mol–1, for the formation of [Fe(pc)(CN)(dmso)]– and [Fe(pc)(CN)2]2–, respectively.
- Full Text:
- Date Issued: 1993
- Authors: Nyokong, Tebello
- Date: 1993
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/295497 , vital:57347 , xlink:href="https://doi.org/10.1039/DT9930003601"
- Description: The kinetics and equilibria for the reaction between cyanide and iron (II) phthalocyanine [Fe(pc)](H2pc = phthalocyanine) in dimethyl sulfoxide (dmso) were studied at 25 °C. The complex [Fe(pc)(CN)2]2– is formed in two consecutive pseudo-first-order processes with k2f= 17.5 ± 0.8 dm3 mol–1 s–1 and k3f= 0.20 ± 0.05 dm3 mol–1 s–1, where k2f and k3f are the rate constants for the binding of the first and second cyanide ligands, respectively. The equilbrium constants were fund to be K2= 3.0 × 103 dm3 mol–1 and K3= 5.7 × 102 dm3 mol–1, for the formation of [Fe(pc)(CN)(dmso)]– and [Fe(pc)(CN)2]2–, respectively.
- Full Text:
- Date Issued: 1993
Interactions between figs (Ficus spp., Moraceae) and fig wasps (Chalcidoidea, Agaonidae)
- Authors: Ware, Anthony Brian
- Date: 1993
- Subjects: Fig -- South Africa Fig wasp -- South Africa Pollination Agaonidae Chalcid wasps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5719 , http://hdl.handle.net/10962/d1005405
- Description: Fig trees (Ficus spp., Moraceae) and fig wasps (Chalcidoidea, Agaonidae) are uniquely associated. In one fig wasp group, the pollinators (Agaoninae), each species is generally host species-specific. The relationship is one of obligate mutualism where the wasps provide pollination services and in return utilises some of the ovules for larval development. Non-pollinating fig wasps (generally belonging to subfamilies other than the Agaoninae) may be gallers or parasitoids, and can also be host species-specific. In the accompanying studies we examined the factors governing the interactions between fig wasps and their host trees. Surveys of fig trees and their associated pollinating fig wasps conducted in southern Africa, Madagascar and The Comores generally confirmed their specific relationships. An examination of F. sycomorlls in Madagascar resulted in the reclassification of F. sakalavarum as a distinct species with its own specific pollinator species. Biological and chemical evidence is presented demonstrating that the pollinators were able to distinguish their hosts through volatiles which emanated from the figs when they were ready to be pollinated. Environmental factors were found to influence wasp behaviour. Ambient temperature governed the timing of wasp emergence from their natal figs. When dispersing from their natal figs, the fig wasps flew upwards and then were blown downwind. Once nearing trees bearing figs ready to be pollinated, the wasps lost height and flew upwind towards the trees. E. baijnathi females apparently avoided figs which already contained a conspecific foundress. Scanning electron microscope studies of pollinating female fig wasp antennae showed that while all the species possessed multiporous plate sensilla, in only a few species were these sensilla elongated. Multiporous plate sensilla elongation is rare or absent among other female chalcids and may have evolved within the Agaoninae in order to facilitate their location on receptive host figs. Pollinator choice specificity appears to break down in a number of cases. In the first case examined, two pollinator species were recorded from the figs of African F. sycomorus. One. C. arabicus, pollinates the figs while the other, C. galili, acts as a 'cuckoo' by utilising some of ovules for oviposition without providing pollen. In the second case three pollinating fig wasp species were recorded from the rigs of F. lutea. Two were found to be incidental visitors and were not specifically attracted to the tree. The hybrid seeds from these crosses were successfully germinated but the seedlings did not grow passed the cotyledon stage of their development. In the concluding study the consequences of Ficus phenology and the structure of the fig's unusual inflorescence on the nonpollinating fig wasp community were examined. Various factors affecting the population levels and species richness were also examined. Future possible research directions were discussed.
- Full Text:
- Date Issued: 1993
- Authors: Ware, Anthony Brian
- Date: 1993
- Subjects: Fig -- South Africa Fig wasp -- South Africa Pollination Agaonidae Chalcid wasps
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5719 , http://hdl.handle.net/10962/d1005405
- Description: Fig trees (Ficus spp., Moraceae) and fig wasps (Chalcidoidea, Agaonidae) are uniquely associated. In one fig wasp group, the pollinators (Agaoninae), each species is generally host species-specific. The relationship is one of obligate mutualism where the wasps provide pollination services and in return utilises some of the ovules for larval development. Non-pollinating fig wasps (generally belonging to subfamilies other than the Agaoninae) may be gallers or parasitoids, and can also be host species-specific. In the accompanying studies we examined the factors governing the interactions between fig wasps and their host trees. Surveys of fig trees and their associated pollinating fig wasps conducted in southern Africa, Madagascar and The Comores generally confirmed their specific relationships. An examination of F. sycomorlls in Madagascar resulted in the reclassification of F. sakalavarum as a distinct species with its own specific pollinator species. Biological and chemical evidence is presented demonstrating that the pollinators were able to distinguish their hosts through volatiles which emanated from the figs when they were ready to be pollinated. Environmental factors were found to influence wasp behaviour. Ambient temperature governed the timing of wasp emergence from their natal figs. When dispersing from their natal figs, the fig wasps flew upwards and then were blown downwind. Once nearing trees bearing figs ready to be pollinated, the wasps lost height and flew upwind towards the trees. E. baijnathi females apparently avoided figs which already contained a conspecific foundress. Scanning electron microscope studies of pollinating female fig wasp antennae showed that while all the species possessed multiporous plate sensilla, in only a few species were these sensilla elongated. Multiporous plate sensilla elongation is rare or absent among other female chalcids and may have evolved within the Agaoninae in order to facilitate their location on receptive host figs. Pollinator choice specificity appears to break down in a number of cases. In the first case examined, two pollinator species were recorded from the figs of African F. sycomorus. One. C. arabicus, pollinates the figs while the other, C. galili, acts as a 'cuckoo' by utilising some of ovules for oviposition without providing pollen. In the second case three pollinating fig wasp species were recorded from the rigs of F. lutea. Two were found to be incidental visitors and were not specifically attracted to the tree. The hybrid seeds from these crosses were successfully germinated but the seedlings did not grow passed the cotyledon stage of their development. In the concluding study the consequences of Ficus phenology and the structure of the fig's unusual inflorescence on the nonpollinating fig wasp community were examined. Various factors affecting the population levels and species richness were also examined. Future possible research directions were discussed.
- Full Text:
- Date Issued: 1993