Nomyayi
- Hogsback festival participants, Composer not specified, Dargie, Dave
- Authors: Hogsback festival participants , Composer not specified , Dargie, Dave
- Date: 1997
- Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
- Language: IsiXhosa
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/345936 , vital:63333 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC349a-04
- Description: Xhosa music at Hogsback festival
- Full Text: false
- Date Issued: 1997
- Authors: Hogsback festival participants , Composer not specified , Dargie, Dave
- Date: 1997
- Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
- Language: IsiXhosa
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/345936 , vital:63333 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC349a-04
- Description: Xhosa music at Hogsback festival
- Full Text: false
- Date Issued: 1997
Novas, eclipses and the English stage, 1598-1608
- Authors: Butler, Guy F
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457738 , vital:75675 , https://hdl.handle.net/10520/AJA1011582X_6
- Description: In the sixteenth and early-seventeenth centuries very few kings, queens or councillors or, indeed, ordinary folk, made any important decisions without consulting their horoscopes. There is no reason to believe that Shakespeare was more sceptical about astrological prediction than his tough-minded Queen; but, even if he were sceptical, he could and did exploit his audience's susceptibility for dramatic ends. A reference to the stars could lift his action from the earthly to the cosmic. Astrological phenomena signalled the involvement of the Heavens with human affairs. In a sense, he and his fellow-dramatists had no option but to exploit the Heavens, because the canopy over half of the Elizabethan stage was referred to as 'the heavens.' It was adorned with paintings of the planets and the signs of the Zodiac. The heavens were built into his theatre, Let us start with eclipses of the sun and moon.
- Full Text:
- Date Issued: 1997
- Authors: Butler, Guy F
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457738 , vital:75675 , https://hdl.handle.net/10520/AJA1011582X_6
- Description: In the sixteenth and early-seventeenth centuries very few kings, queens or councillors or, indeed, ordinary folk, made any important decisions without consulting their horoscopes. There is no reason to believe that Shakespeare was more sceptical about astrological prediction than his tough-minded Queen; but, even if he were sceptical, he could and did exploit his audience's susceptibility for dramatic ends. A reference to the stars could lift his action from the earthly to the cosmic. Astrological phenomena signalled the involvement of the Heavens with human affairs. In a sense, he and his fellow-dramatists had no option but to exploit the Heavens, because the canopy over half of the Elizabethan stage was referred to as 'the heavens.' It was adorned with paintings of the planets and the signs of the Zodiac. The heavens were built into his theatre, Let us start with eclipses of the sun and moon.
- Full Text:
- Date Issued: 1997
Nxaka Nxaka
- Performer not specified, Composer not specified, Dargie, Dave
- Authors: Performer not specified , Composer not specified , Dargie, Dave
- Date: 1997
- Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
- Language: IsiXhosa
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/343086 , vital:62967 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC343a-08
- Description: Traditional xhosa music accompanied by clapping, rattle and drum
- Full Text: false
- Date Issued: 1997
- Authors: Performer not specified , Composer not specified , Dargie, Dave
- Date: 1997
- Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
- Language: IsiXhosa
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/343086 , vital:62967 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC343a-08
- Description: Traditional xhosa music accompanied by clapping, rattle and drum
- Full Text: false
- Date Issued: 1997
On the life history of the lesser gurnard (Scorpaeniformes: Triglidae) inhabiting the Agulhas Bank, South Africa
- Authors: Booth, Anthony J
- Date: 1997
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125434 , vital:35782 , https://doi.10.1111/j.1095-8649.1997.tb01133.x
- Description: Fishes of the genus Labeo are widely distributed throughout Africa and consist of at least 80 species which comprise 16.4% of the African cyprinid ichthyofauna (Reid 1985). Most labeo species are also commercially important throughout the African continent, having contributed significantly to various fisheries. Their roe (sensu caviar) is often harvested as an additional bycatch (Skelton et al. 1991). Despite their obvious importance, the few studies that have investigated aspects of their life history have been conducted on the larger commercial species (Lowe 1952, Mulder 1973, Balon et al. 1974, Potgieter 1974, Baird 1976, Tomasson et al. 1984, van Zyl et al. 1995).
- Full Text:
- Date Issued: 1997
- Authors: Booth, Anthony J
- Date: 1997
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125434 , vital:35782 , https://doi.10.1111/j.1095-8649.1997.tb01133.x
- Description: Fishes of the genus Labeo are widely distributed throughout Africa and consist of at least 80 species which comprise 16.4% of the African cyprinid ichthyofauna (Reid 1985). Most labeo species are also commercially important throughout the African continent, having contributed significantly to various fisheries. Their roe (sensu caviar) is often harvested as an additional bycatch (Skelton et al. 1991). Despite their obvious importance, the few studies that have investigated aspects of their life history have been conducted on the larger commercial species (Lowe 1952, Mulder 1973, Balon et al. 1974, Potgieter 1974, Baird 1976, Tomasson et al. 1984, van Zyl et al. 1995).
- Full Text:
- Date Issued: 1997
Paedophagia among cichlid fishes of Lake Victoria and Lake Malawi/Nyasa
- Ribbink, Anthony J, Ribbink, Anthea C
- Authors: Ribbink, Anthony J , Ribbink, Anthea C
- Date: 1997
- Language: English
- Type: text , Article
- Identifier: vital:7134 , http://hdl.handle.net/10962/d1011777
- Description: Paedophages, as defined here, are cichlids which exploit the protective tactics of other cichlids to steal the offspring from them. The different tactics are reviewed here and a new form of paedophagy is described, in which retrieval of free-swimming young is stimulated by the paedophage so that the offspring gather at the parent's mouth, where they are readily caught by the paedophage.
- Full Text: false
- Date Issued: 1997
- Authors: Ribbink, Anthony J , Ribbink, Anthea C
- Date: 1997
- Language: English
- Type: text , Article
- Identifier: vital:7134 , http://hdl.handle.net/10962/d1011777
- Description: Paedophages, as defined here, are cichlids which exploit the protective tactics of other cichlids to steal the offspring from them. The different tactics are reviewed here and a new form of paedophagy is described, in which retrieval of free-swimming young is stimulated by the paedophage so that the offspring gather at the parent's mouth, where they are readily caught by the paedophage.
- Full Text: false
- Date Issued: 1997
Painting of three African women
- Authors: Ndaba, Godfrey
- Date: 1997 , 2022-10-11
- Subjects: Bam, Brigalia
- Language: English
- Type: painting , realia
- Identifier: http://hdl.handle.net/10948/57145 , vital:57341
- Description: Dr. Brigalia Bam was gifted a painting from the Electoral Commission of Uganda. A Catholic Nun decided to give Dr. Brigalia Bam the painting of three African women because of her love and care for women. , Dr Bam told the Catholic Nun about the sad death of an Anglican Bishop who had been murdered by Idi Amin, the former President of Uganda. Dr. Brigalia Bam also focused on the stories of women widows of Uganda. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 1997
- Authors: Ndaba, Godfrey
- Date: 1997 , 2022-10-11
- Subjects: Bam, Brigalia
- Language: English
- Type: painting , realia
- Identifier: http://hdl.handle.net/10948/57145 , vital:57341
- Description: Dr. Brigalia Bam was gifted a painting from the Electoral Commission of Uganda. A Catholic Nun decided to give Dr. Brigalia Bam the painting of three African women because of her love and care for women. , Dr Bam told the Catholic Nun about the sad death of an Anglican Bishop who had been murdered by Idi Amin, the former President of Uganda. Dr. Brigalia Bam also focused on the stories of women widows of Uganda. , Donated/gifted to Nelson Mandela University Archives , Forms part of: Brigalia Bam collection
- Full Text: false
- Date Issued: 1997
Parasitism and invasive species : an ecological study of mussel populations
- Calvo Ugarteburu, Miren Gurutze
- Authors: Calvo Ugarteburu, Miren Gurutze
- Date: 1997
- Subjects: Perna -- Parasites Mytilidae -- Parasites Perna -- Ecology Mytilidae -- Ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5736 , http://hdl.handle.net/10962/d1005422
- Description: The Mediterranean mussel Mytilus galloprovincialis, was introduced accidentally to South Africa and has since become invasive. One possible explanation for the success of this species is that it has been released from the effects of parasites which affect the indigenous species of mussels. The aim of this work was to examine the parasitic load of different mussel populations along the southern African coast and to assess the effects of parasites on their hosts. A survey was done to quantify the levels of parasitism in indigenous populations of Perna perna from Southern Africa and of Mytilus galloprovincialis from South Africa (where it is exotic) and Spain (where it is indigenous). This survey was carried out at three different geographic scales: small scale (metres), studying the incidence of parasites within a mussel bed; medium scale (kilometres to tens of kilometres), comparing prevalences of infection among different localities; and large scale (hundreds to thousands of kilometres), examining infection rates along the Southern African coast, as well as the coast of the Basque Country (North Spain). During this survey metazoan parasites other than trematodes were rare. Four species of trematodes were commonly found infecting the indigenous mussel Perna perna. These were metacercariae of the genus Proctoeces, bucephalid sporocysts, encysted metacercariae on the labial palps and gelatinous cysts with metacercariae inside. A detailed description of Proctoeces is given; the other parasites are described elsewhere. No parasites were found in M. galloprovincialis either in South Africa or in Spain. This thesis concentrates on the study of prevalences of Proctoeces and bucephalid sporocysts and their effects on Perna perna. Infection rates with Proctoeces are highly dependent on the sex of the host, with more females than males being infected, and are also size dependent, though only for females. Identification of the sex of mussels infected with bucephalid sporocysts is often not possible since the sporocysts spread over the gonad and replace it. Prevalence of infection with this parasite also increases with the size of the host. To study the influence of Proctoeces and bucephalid sporocysts on the ecological fitness of Perna perna, their effects on survival and competitive ability were tested. The results showed significant negative effects. Both parasites significantly depressed condition but only after spawning, when the mussels were already stressed. In order to check for effects on host survival, the effects of both parasites on mortality rates, gaping behaviour and water loss of mussels exposed to air were also examined. Neither parasite affected mortality rate or gaping behaviour of Perna perna. Proctoeces did not affect the amount of water lost by mussels, but the bucephalid sporocysts did. Mussels infected with sporocysts lost significantly more water than non-infected individuals. This increase in water loss was not related to the gaping behaviour, but a test of the strength of the adductor muscles showed that less force was needed to open mussels with bucephalid sporocysts than non-infected mussels. This was not the case for mussels infected by Proctoeces. Weaker mussels will fail to seal the valves properly, resulting in an increase of water loss on exposure to air by evaporation. Another factor that will have an obvious effect on a population is the reproductive output of the animals. Histological sections of the gonad of infected and non-infected females were cut to study the effects of both parasites on reproduction. Statistical tests comparing the numbers and sizes of oocytes in females infected with Proctoeces and non-infected females showed no significant differences. However, bucephalid sporocysts have a dramatic effect on reproduction by castrating the host, leaving no trace of sex products. One of the major factors shaping the composition of a mussel bed is competition for space and food, with smaller mussels being at a competitive disadvantage. Thus, in order to examine effects of both parasites on the competitive ability of Perna perna, summer and winter growth rates were compared for infected and non-infected mussels. Proctoeces reduced growth both in summer and in winter whilst bucephalid sporocysts had no significant effect. Both growth and reproduction are important components of the energy budget of an animal, and each is affected by either Proctoeces or the bucephalid sporocysts. In an attempt to test if Perna perna compensates energetically for these negative effects, filtration rates and oxygen consumption of mussels with and without parasites were measured. Neither parasite had a significant effect on filtration rates or oxygen consumption of the host. All these results indicate that both Proctoeces and the bucephalid sporocysts have a detrimental effect on their host, and that the mussels do not compensate for these negative effects. There is neither an increase in filtration, nor a decrease in respiration to balance the energy lost to the parasite. The two parasites studied affect the host in different but complementary ways. The effects of both parasites are concentrated on those size classes of mussel which channel most energy into the portion of the energy budget affected by the parasite. Proctoeces affects growth only in the smaller individuals, which under normal conditions would put most energy into growth; and the bucephalid sporocysts castrate the bigger mussels, which would expend most energy on reproduction. By reducing growth rates of small mussels or castrating large mussels, these parasites effectively remove them from the breeding population and reduce their competitive abilities. These negative effects, together with the high prevalence of both parasites in Perna perna along the South African coast and their absence in Mytilus galloprovincialis, suggest that parasites may be an important reason for the success of Mytilus.
- Full Text:
- Date Issued: 1997
- Authors: Calvo Ugarteburu, Miren Gurutze
- Date: 1997
- Subjects: Perna -- Parasites Mytilidae -- Parasites Perna -- Ecology Mytilidae -- Ecology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5736 , http://hdl.handle.net/10962/d1005422
- Description: The Mediterranean mussel Mytilus galloprovincialis, was introduced accidentally to South Africa and has since become invasive. One possible explanation for the success of this species is that it has been released from the effects of parasites which affect the indigenous species of mussels. The aim of this work was to examine the parasitic load of different mussel populations along the southern African coast and to assess the effects of parasites on their hosts. A survey was done to quantify the levels of parasitism in indigenous populations of Perna perna from Southern Africa and of Mytilus galloprovincialis from South Africa (where it is exotic) and Spain (where it is indigenous). This survey was carried out at three different geographic scales: small scale (metres), studying the incidence of parasites within a mussel bed; medium scale (kilometres to tens of kilometres), comparing prevalences of infection among different localities; and large scale (hundreds to thousands of kilometres), examining infection rates along the Southern African coast, as well as the coast of the Basque Country (North Spain). During this survey metazoan parasites other than trematodes were rare. Four species of trematodes were commonly found infecting the indigenous mussel Perna perna. These were metacercariae of the genus Proctoeces, bucephalid sporocysts, encysted metacercariae on the labial palps and gelatinous cysts with metacercariae inside. A detailed description of Proctoeces is given; the other parasites are described elsewhere. No parasites were found in M. galloprovincialis either in South Africa or in Spain. This thesis concentrates on the study of prevalences of Proctoeces and bucephalid sporocysts and their effects on Perna perna. Infection rates with Proctoeces are highly dependent on the sex of the host, with more females than males being infected, and are also size dependent, though only for females. Identification of the sex of mussels infected with bucephalid sporocysts is often not possible since the sporocysts spread over the gonad and replace it. Prevalence of infection with this parasite also increases with the size of the host. To study the influence of Proctoeces and bucephalid sporocysts on the ecological fitness of Perna perna, their effects on survival and competitive ability were tested. The results showed significant negative effects. Both parasites significantly depressed condition but only after spawning, when the mussels were already stressed. In order to check for effects on host survival, the effects of both parasites on mortality rates, gaping behaviour and water loss of mussels exposed to air were also examined. Neither parasite affected mortality rate or gaping behaviour of Perna perna. Proctoeces did not affect the amount of water lost by mussels, but the bucephalid sporocysts did. Mussels infected with sporocysts lost significantly more water than non-infected individuals. This increase in water loss was not related to the gaping behaviour, but a test of the strength of the adductor muscles showed that less force was needed to open mussels with bucephalid sporocysts than non-infected mussels. This was not the case for mussels infected by Proctoeces. Weaker mussels will fail to seal the valves properly, resulting in an increase of water loss on exposure to air by evaporation. Another factor that will have an obvious effect on a population is the reproductive output of the animals. Histological sections of the gonad of infected and non-infected females were cut to study the effects of both parasites on reproduction. Statistical tests comparing the numbers and sizes of oocytes in females infected with Proctoeces and non-infected females showed no significant differences. However, bucephalid sporocysts have a dramatic effect on reproduction by castrating the host, leaving no trace of sex products. One of the major factors shaping the composition of a mussel bed is competition for space and food, with smaller mussels being at a competitive disadvantage. Thus, in order to examine effects of both parasites on the competitive ability of Perna perna, summer and winter growth rates were compared for infected and non-infected mussels. Proctoeces reduced growth both in summer and in winter whilst bucephalid sporocysts had no significant effect. Both growth and reproduction are important components of the energy budget of an animal, and each is affected by either Proctoeces or the bucephalid sporocysts. In an attempt to test if Perna perna compensates energetically for these negative effects, filtration rates and oxygen consumption of mussels with and without parasites were measured. Neither parasite had a significant effect on filtration rates or oxygen consumption of the host. All these results indicate that both Proctoeces and the bucephalid sporocysts have a detrimental effect on their host, and that the mussels do not compensate for these negative effects. There is neither an increase in filtration, nor a decrease in respiration to balance the energy lost to the parasite. The two parasites studied affect the host in different but complementary ways. The effects of both parasites are concentrated on those size classes of mussel which channel most energy into the portion of the energy budget affected by the parasite. Proctoeces affects growth only in the smaller individuals, which under normal conditions would put most energy into growth; and the bucephalid sporocysts castrate the bigger mussels, which would expend most energy on reproduction. By reducing growth rates of small mussels or castrating large mussels, these parasites effectively remove them from the breeding population and reduce their competitive abilities. These negative effects, together with the high prevalence of both parasites in Perna perna along the South African coast and their absence in Mytilus galloprovincialis, suggest that parasites may be an important reason for the success of Mytilus.
- Full Text:
- Date Issued: 1997
Participatory programme development at an environmental education centre through action research involving secondary school teachers
- Authors: Klein, Charmain Phillida
- Date: 1997
- Subjects: Environmental education -- Study and teaching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1690 , http://hdl.handle.net/10962/d1003573
- Description: This mini-thesis documents and analyses an action research project which I conducted with secohdary school teachers. The teachers wished to learn more about environmental education so that they could run their own programmes. I, on the other hand, wanted to improve environmental education programmes offered at the centre where I worked. I hoped that through encouraging teacher participation and involvement, I could begin a process through which the teachers themselves could contribute to, and be in greater control of, their own learning in environmental education. As an introduction to this mini-thesis, I provide some background information on the centre, and state the reasons for having embarked on this project. In addition, I outline the literature and various research findings pertinent to this study. For the purpose of this study, I have selected emancipatory action research as a mode of research, since I believe that emancipatory action research, which embodies processes of reflection and informed action, constitutes the possibility for authentic, emancipatory change in the practice of teachers. The bulk of this thesis, therefore, documents the first two cycles of the action research process and the experiences of those involved in the process. I also briefly comment on some of the claims of action research as a method for research. An important feature of this thesis is that it addresses the possibilities of and constraints to implementing education for the environment in the teachers' practices. The existence of the latter is acknowledged and discussed from my perspective and those of the participating teachers. The study, furthermore, documents teachers' understandings of environmental education, and how this determines the kind of environmental education activities in which they engage. In the final analysis, I argue that the education system we inherited from the apartheid regime has had the effect of producing passive, disempowered and highly demotivated teachers with extremely low levels of self confidence and assertiveness. Despite this fact, I have not only had the opportunity to wltness some positive attitudinal changes occurring in teachers as the study progressed; the project has also enhanced my own understanding of environmental education and the effect the apartheid education system had in shaping my own thoughts and life.
- Full Text:
- Date Issued: 1997
- Authors: Klein, Charmain Phillida
- Date: 1997
- Subjects: Environmental education -- Study and teaching (Secondary) -- South Africa
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1690 , http://hdl.handle.net/10962/d1003573
- Description: This mini-thesis documents and analyses an action research project which I conducted with secohdary school teachers. The teachers wished to learn more about environmental education so that they could run their own programmes. I, on the other hand, wanted to improve environmental education programmes offered at the centre where I worked. I hoped that through encouraging teacher participation and involvement, I could begin a process through which the teachers themselves could contribute to, and be in greater control of, their own learning in environmental education. As an introduction to this mini-thesis, I provide some background information on the centre, and state the reasons for having embarked on this project. In addition, I outline the literature and various research findings pertinent to this study. For the purpose of this study, I have selected emancipatory action research as a mode of research, since I believe that emancipatory action research, which embodies processes of reflection and informed action, constitutes the possibility for authentic, emancipatory change in the practice of teachers. The bulk of this thesis, therefore, documents the first two cycles of the action research process and the experiences of those involved in the process. I also briefly comment on some of the claims of action research as a method for research. An important feature of this thesis is that it addresses the possibilities of and constraints to implementing education for the environment in the teachers' practices. The existence of the latter is acknowledged and discussed from my perspective and those of the participating teachers. The study, furthermore, documents teachers' understandings of environmental education, and how this determines the kind of environmental education activities in which they engage. In the final analysis, I argue that the education system we inherited from the apartheid regime has had the effect of producing passive, disempowered and highly demotivated teachers with extremely low levels of self confidence and assertiveness. Despite this fact, I have not only had the opportunity to wltness some positive attitudinal changes occurring in teachers as the study progressed; the project has also enhanced my own understanding of environmental education and the effect the apartheid education system had in shaping my own thoughts and life.
- Full Text:
- Date Issued: 1997
Patterns of sexual size dimorphism in African cichlid fishes
- Erlandsson, A, Ribbink, Anthony J
- Authors: Erlandsson, A , Ribbink, Anthony J
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:7135 , http://hdl.handle.net/10962/d1011778
- Description: Although the Cichlidae is a well-studied family of African fishes, the evolution of sexual size dimorphism (SSD) and its relation to life-history, behaviour, feeding and habitat have not been comparatively examined. The investigation of SSD reported here was based on a study of the scientific literature. Prerequisites to such studies are records of maximum size of adult males and females. Disappointingly few authors published such measurements, so the data are fewer than anticipated given that the cichlids are such a species-rich group. Now that this omission has been noted, it is hoped that investigations of the future will include information on maximum size of adults of both sexes. Data from 215 species showed great variation in the degree and direction of SSD, without any really strong trends being evident. In the majority of species, males were larger than females or there was no size difference between the sexes. In 10% (21 species), females were larger than males. All of these are lacustrine, tend to live in deep water, often over muddy substrata and to feed to a greater extent than expected on non-defendable food sources. The degree of SSD increases with increasing body size in species where males are the larger sex and decreases in species where females are the larger In territorial species, in which competition between territorial males is intensive, males are the larger sex. The expectation that polygynous cichlids would show a more marked degree of SSD than monogamous species was not met. Larger size in females (with one exception) occurs in mouthbrooding species only. Males are the larger sex in substratum brooders. It seems that the degree and direction of sexual size dimorphism in cichlids is a consequence of a balance of natural and sexual selection, but there is a need to increase the sample size to understand the interplay of these selection pressures and to establish the validity of the emerging trends.
- Full Text: false
- Date Issued: 1997
- Authors: Erlandsson, A , Ribbink, Anthony J
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:7135 , http://hdl.handle.net/10962/d1011778
- Description: Although the Cichlidae is a well-studied family of African fishes, the evolution of sexual size dimorphism (SSD) and its relation to life-history, behaviour, feeding and habitat have not been comparatively examined. The investigation of SSD reported here was based on a study of the scientific literature. Prerequisites to such studies are records of maximum size of adult males and females. Disappointingly few authors published such measurements, so the data are fewer than anticipated given that the cichlids are such a species-rich group. Now that this omission has been noted, it is hoped that investigations of the future will include information on maximum size of adults of both sexes. Data from 215 species showed great variation in the degree and direction of SSD, without any really strong trends being evident. In the majority of species, males were larger than females or there was no size difference between the sexes. In 10% (21 species), females were larger than males. All of these are lacustrine, tend to live in deep water, often over muddy substrata and to feed to a greater extent than expected on non-defendable food sources. The degree of SSD increases with increasing body size in species where males are the larger sex and decreases in species where females are the larger In territorial species, in which competition between territorial males is intensive, males are the larger sex. The expectation that polygynous cichlids would show a more marked degree of SSD than monogamous species was not met. Larger size in females (with one exception) occurs in mouthbrooding species only. Males are the larger sex in substratum brooders. It seems that the degree and direction of sexual size dimorphism in cichlids is a consequence of a balance of natural and sexual selection, but there is a need to increase the sample size to understand the interplay of these selection pressures and to establish the validity of the emerging trends.
- Full Text: false
- Date Issued: 1997
Periglacial features in the vicinity of Tiffindell Ski Resort, North East Cape Drakensberg, South Africa, and their implications for the development of the resort
- Authors: Kück, Karen Melody
- Date: 1997
- Subjects: Tiffindell Ski Resort (South Africa) , Slopes (Physical geography) -- South Africa -- Eastern Cape , Landforms -- South Africa -- Eastern Cape , Climatic geomorphology -- South Africa -- Eastern Cape , Drakensberg Mountains
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4844 , http://hdl.handle.net/10962/d1005520 , Tiffindell Ski Resort (South Africa) , Slopes (Physical geography) -- South Africa -- Eastern Cape , Landforms -- South Africa -- Eastern Cape , Climatic geomorphology -- South Africa -- Eastern Cape , Drakensberg Mountains
- Description: This thesis provides a description of the periglacial environment and features in the vicinity of Tiffindell Ski resort, on the slopes of Ben MacDhui (3001.2m.), the highest point of the East Cape Drakensberg, South Africa. Active and inactive periglacial features were located, mapped and described. Of particular interest were periglaciar slope deposits including gelifluction turf-banked lobes and stone lobes, and cryoturbation features including polygons and thufur. Local environmental factors, such as aspect, moisture, topography, soil texture and depth of freezing, appear to act as important controls on the spatial distribution of the periglacial features. Identification and quantification of periglacial processes in the regolith was investigated using temperature and soil moisture sensors coupled to dataloggers. Research was undertaken over a 16 month period from June 1995 to September 1996 so that comparisons between the winter conditions of 1995 and 1996 could be drawn. The Tiffindell area was observed to be characterised in the winter months by 'diurnal freezethaw days', as well as by 'ice days', 1996 experiencing colder temperatures than 1995. With more than 78% of the days from May to September 1996 being 'ice days', and simultaneously experiencing high soil moisture contents, freezing penetration to a depth of greater than 0.2m was observed to occur in the Tiffindell area, causing frost heave and gelifluction. The summer thaw of ice lenses that developed in the cold winter months caused surface movement downslope of gelifluction lobes of up to 39mm over an 18 month period, although movement declined rapidly with depth and was essentially restricted to the uppermost 130mm of the regolith. Other features such as sorted and non-sorted polygons and thufur were identified and found to be active under the present climatic conditions and depth of frost penetration at Tiffindell. Stone lobes were identified on the south and southeast-facing slopes at Tiffindell, but are apparently inactive under present climatic conditions. Their existence suggests the presence of severe seasonal frost in the past. The implications of the air and ground surface temperatures, and of seasonal frost penetration for the development of Tiffindell Ski resort were considered, and suggestions regarding their economic significance are presented.
- Full Text:
- Date Issued: 1997
- Authors: Kück, Karen Melody
- Date: 1997
- Subjects: Tiffindell Ski Resort (South Africa) , Slopes (Physical geography) -- South Africa -- Eastern Cape , Landforms -- South Africa -- Eastern Cape , Climatic geomorphology -- South Africa -- Eastern Cape , Drakensberg Mountains
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4844 , http://hdl.handle.net/10962/d1005520 , Tiffindell Ski Resort (South Africa) , Slopes (Physical geography) -- South Africa -- Eastern Cape , Landforms -- South Africa -- Eastern Cape , Climatic geomorphology -- South Africa -- Eastern Cape , Drakensberg Mountains
- Description: This thesis provides a description of the periglacial environment and features in the vicinity of Tiffindell Ski resort, on the slopes of Ben MacDhui (3001.2m.), the highest point of the East Cape Drakensberg, South Africa. Active and inactive periglacial features were located, mapped and described. Of particular interest were periglaciar slope deposits including gelifluction turf-banked lobes and stone lobes, and cryoturbation features including polygons and thufur. Local environmental factors, such as aspect, moisture, topography, soil texture and depth of freezing, appear to act as important controls on the spatial distribution of the periglacial features. Identification and quantification of periglacial processes in the regolith was investigated using temperature and soil moisture sensors coupled to dataloggers. Research was undertaken over a 16 month period from June 1995 to September 1996 so that comparisons between the winter conditions of 1995 and 1996 could be drawn. The Tiffindell area was observed to be characterised in the winter months by 'diurnal freezethaw days', as well as by 'ice days', 1996 experiencing colder temperatures than 1995. With more than 78% of the days from May to September 1996 being 'ice days', and simultaneously experiencing high soil moisture contents, freezing penetration to a depth of greater than 0.2m was observed to occur in the Tiffindell area, causing frost heave and gelifluction. The summer thaw of ice lenses that developed in the cold winter months caused surface movement downslope of gelifluction lobes of up to 39mm over an 18 month period, although movement declined rapidly with depth and was essentially restricted to the uppermost 130mm of the regolith. Other features such as sorted and non-sorted polygons and thufur were identified and found to be active under the present climatic conditions and depth of frost penetration at Tiffindell. Stone lobes were identified on the south and southeast-facing slopes at Tiffindell, but are apparently inactive under present climatic conditions. Their existence suggests the presence of severe seasonal frost in the past. The implications of the air and ground surface temperatures, and of seasonal frost penetration for the development of Tiffindell Ski resort were considered, and suggestions regarding their economic significance are presented.
- Full Text:
- Date Issued: 1997
Petrology and geochemistry of peridotite xenoliths from the Letlhakane kimberlites, Botswana
- Stiefenhofer, Johann, Viljoen, K S, Marsh, Julian S
- Authors: Stiefenhofer, Johann , Viljoen, K S , Marsh, Julian S
- Date: 1997
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149705 , vital:38876 , https://doi.org/10.1007/s004100050272
- Description: The diamondiferous Letlhakane kimberlites are intruded into the Proterozoic Magondi Belt of Botswana. Given the general correlation of diamondiferous kimberlites with Archaean cratons, the apparent tectonic setting of these kimberlites is somewhat anomalous. Xenoliths in kimberlite diatremes provide a window into the underlying crust and upper mantle and, with the aid of detailed petrological and geochemical study, can help unravel problems of tectonic setting.
- Full Text: false
- Date Issued: 1997
- Authors: Stiefenhofer, Johann , Viljoen, K S , Marsh, Julian S
- Date: 1997
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149705 , vital:38876 , https://doi.org/10.1007/s004100050272
- Description: The diamondiferous Letlhakane kimberlites are intruded into the Proterozoic Magondi Belt of Botswana. Given the general correlation of diamondiferous kimberlites with Archaean cratons, the apparent tectonic setting of these kimberlites is somewhat anomalous. Xenoliths in kimberlite diatremes provide a window into the underlying crust and upper mantle and, with the aid of detailed petrological and geochemical study, can help unravel problems of tectonic setting.
- Full Text: false
- Date Issued: 1997
Photosensitization reactions of neodymium, dysprosium and lutetium diphthalocyanine
- Nensala, Ngudiankama, Nyokong, Tebello
- Authors: Nensala, Ngudiankama , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:57084 , xlink:href="https://doi.org/10.1016/S0277-5387(97)00045-4"
- Description: Photolysis, using a visible radiation, of diphthalocyanine complexes of NdIII, DyIII and LuIII ([Pc(−2)NdIIIPc(−2)]−, [Pc(−2)DyIIIPc(−2)]− and [Pc(−2)LuIIIPc(−2)]−, respectively) in the presence of pentachlorophenol (PCP) or SO2 results in the one-electron oxidation of the diphthalocyanine species to Pc(−1)NdIIIPc(−2), Pc(−1)DyIIIPc(−2) and Pc(−2)LuIIIPc(−2), respectively. The PCP is reductively dechlorinated to tetra- and trichlorophenols. The quantum yields for the photosensitization reactions are of the order 10−4.
- Full Text:
- Date Issued: 1997
- Authors: Nensala, Ngudiankama , Nyokong, Tebello
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/${Handle} , vital:57084 , xlink:href="https://doi.org/10.1016/S0277-5387(97)00045-4"
- Description: Photolysis, using a visible radiation, of diphthalocyanine complexes of NdIII, DyIII and LuIII ([Pc(−2)NdIIIPc(−2)]−, [Pc(−2)DyIIIPc(−2)]− and [Pc(−2)LuIIIPc(−2)]−, respectively) in the presence of pentachlorophenol (PCP) or SO2 results in the one-electron oxidation of the diphthalocyanine species to Pc(−1)NdIIIPc(−2), Pc(−1)DyIIIPc(−2) and Pc(−2)LuIIIPc(−2), respectively. The PCP is reductively dechlorinated to tetra- and trichlorophenols. The quantum yields for the photosensitization reactions are of the order 10−4.
- Full Text:
- Date Issued: 1997
Plasmodesmatal frequency in relation to short-distance transport and phloem loading in leaves of barley (Hordeum vulgare). Phloem is not loaded directly from the symplast
- Botha, Christiaan E J, Cross, Robin H M
- Authors: Botha, Christiaan E J , Cross, Robin H M
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:6504 , http://hdl.handle.net/10962/d1005928
- Description: We investigated the phloem loading pathway in barley, by determining plasmodesmatal frequencies at the electron microscope level for both intermediate and small blade bundles of mature barley leaves. Lucifer yellow was injected intercellularly into bundle sheath, vascular parenchyma, and thin-walled sieve tubes. Passage of this symplastically transported dye was monitored with an epifluorescence microscope under blue light. Low plasmodesmatal frequencies endarch to the bundle sheath cells are relatively low for most interfaces terminating at the thin- and thick-walled sieve tubes within this C3 species. Lack of connections between vascular parenchyma and sieve tubes, and low frequencies (0.5% plasmodesmata per μm cell wall interface) of connections between vascular parenchyma and companion cells, as well as the very low frequency of pore-plasmodesmatal connections between companion cells and sieve tubes in small bundles (0.2% plasmodesmata per μm cell wall interface), suggest that the companion cell-sieve tube complex is symplastically isolated from other vascular parenchyma cells in small bundles. The degree of cellular connectivity and the potential isolation of the companion cell-sieve tube complex was determined electrophysiologically, using an electrometer coupled to microcapillary electrodes. The less negative cell potential {average -52 mV) from mesophyll to the vascular parenchyma cells contrasted sharply with the more negative potential (-122.5 mV) recorded for the companion cell-thin-walled sieve tube complex. Although intercellular injection of lucifer yellow clearly demonstrated rapid (0.75 μm s-1) longitudinal and radial transport in the bundle sheath-vascular parenchyma complex, as well as from the bundle sheath through transverse veins to adjacent longitudinal veins, we were neither able to detect nor present unequivocal evidence in support of the symplastic connectivity of the sieve tubes to the vascular parenchyma. Injection of the companion cell-sieve tube complex, did not demonstrate backward connectivity to the bundle sheath. We conclude that the low plasmodesmatal frequencies, coupled with a two-domain electropotential zonation configuration, and the negative transport experiments using lucifer yellow, precludes symplastic phloem loading in barley leaves.
- Full Text:
- Date Issued: 1997
- Authors: Botha, Christiaan E J , Cross, Robin H M
- Date: 1997
- Language: English
- Type: Article
- Identifier: vital:6504 , http://hdl.handle.net/10962/d1005928
- Description: We investigated the phloem loading pathway in barley, by determining plasmodesmatal frequencies at the electron microscope level for both intermediate and small blade bundles of mature barley leaves. Lucifer yellow was injected intercellularly into bundle sheath, vascular parenchyma, and thin-walled sieve tubes. Passage of this symplastically transported dye was monitored with an epifluorescence microscope under blue light. Low plasmodesmatal frequencies endarch to the bundle sheath cells are relatively low for most interfaces terminating at the thin- and thick-walled sieve tubes within this C3 species. Lack of connections between vascular parenchyma and sieve tubes, and low frequencies (0.5% plasmodesmata per μm cell wall interface) of connections between vascular parenchyma and companion cells, as well as the very low frequency of pore-plasmodesmatal connections between companion cells and sieve tubes in small bundles (0.2% plasmodesmata per μm cell wall interface), suggest that the companion cell-sieve tube complex is symplastically isolated from other vascular parenchyma cells in small bundles. The degree of cellular connectivity and the potential isolation of the companion cell-sieve tube complex was determined electrophysiologically, using an electrometer coupled to microcapillary electrodes. The less negative cell potential {average -52 mV) from mesophyll to the vascular parenchyma cells contrasted sharply with the more negative potential (-122.5 mV) recorded for the companion cell-thin-walled sieve tube complex. Although intercellular injection of lucifer yellow clearly demonstrated rapid (0.75 μm s-1) longitudinal and radial transport in the bundle sheath-vascular parenchyma complex, as well as from the bundle sheath through transverse veins to adjacent longitudinal veins, we were neither able to detect nor present unequivocal evidence in support of the symplastic connectivity of the sieve tubes to the vascular parenchyma. Injection of the companion cell-sieve tube complex, did not demonstrate backward connectivity to the bundle sheath. We conclude that the low plasmodesmatal frequencies, coupled with a two-domain electropotential zonation configuration, and the negative transport experiments using lucifer yellow, precludes symplastic phloem loading in barley leaves.
- Full Text:
- Date Issued: 1997
Policy Memo - Engineering hours of work
- NALEDI
- Authors: NALEDI
- Date: 1997
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/151200 , vital:39038
- Description: The National Union of Metal Workers of South Africa (Numsa). following Cosatu, has since its foundation argued for a 40 hour week and a ban on overtime to increase employment. The goal of a shorter working week should not. however, limit itself to employment. Metal workers work long, hard hours, an average 49 hour week in 1995. (ILO.1996:334) Shift workers often work longer, with serious health and safety risks, including shorter lives. A poor and inefficient transport system cuts at least another 5 to 10 hours a week from the time urban africans spend away from home, community and leisure. (CSS. 1995)1 Workers too must have the right to a healthy work environment and proper access to leisure time and family. The organisation of working time is also important, impacting on the ability of workers to effectively access education and training.
- Full Text:
- Date Issued: 1997
- Authors: NALEDI
- Date: 1997
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/151200 , vital:39038
- Description: The National Union of Metal Workers of South Africa (Numsa). following Cosatu, has since its foundation argued for a 40 hour week and a ban on overtime to increase employment. The goal of a shorter working week should not. however, limit itself to employment. Metal workers work long, hard hours, an average 49 hour week in 1995. (ILO.1996:334) Shift workers often work longer, with serious health and safety risks, including shorter lives. A poor and inefficient transport system cuts at least another 5 to 10 hours a week from the time urban africans spend away from home, community and leisure. (CSS. 1995)1 Workers too must have the right to a healthy work environment and proper access to leisure time and family. The organisation of working time is also important, impacting on the ability of workers to effectively access education and training.
- Full Text:
- Date Issued: 1997
Punishment in schools: perspectives of parents, teachers and pupils
- Authors: Sedumedi, Susan Dimakatso
- Date: 1997
- Subjects: Punishment -- South Africa , Discipline of children -- Psychological aspects , Discipline of children -- South Africa , High school teachers -- South Africa -- Attitudes , High school students -- South Africa -- Attitudes , Parents -- South Africa -- Attitudes , Corporal punishment , Corporal punishment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3051 , http://hdl.handle.net/10962/d1002560 , Punishment -- South Africa , Discipline of children -- Psychological aspects , Discipline of children -- South Africa , High school teachers -- South Africa -- Attitudes , High school students -- South Africa -- Attitudes , Parents -- South Africa -- Attitudes , Corporal punishment , Corporal punishment -- South Africa
- Description: While some research has been done on the use of corporal punishment in South African schools, there is a dearth of research on other forms of punishment and little has been done to research the meaning of punishment. This study explores the meaning of punishment in a high school context and focuses on the different attitudes of parents, teachers and pupils, with a view to identifying, in particular, how they justify the use of punishment. A sample of 50 pupils, 30 teachers and 30 parents were selected for the study. Focus groups and a questionnaire with closed and open-ended questions were used to collect the data. The questionnaire was constructed to explore themes which emerged in the focus group discussions . Results were grouped into themes and arranged by tables , and the Chi-square test of statistical significance was used to analyze some of the data. The results show that the meaning and the approach to punishment is differently construed by participants. Parents construe punishment as an educative instrument and a disciplinary measure used for the good of pupils and the society. Teachers see it as a discip1inary measure, a strategy used for effective learning, and a negative stimulus used to inflict pain towards the goal of an orderly school environment. To pupils the punishment scene provides an opportunity for what they perceive as sadistic enjoyment and as something negative which is used by teachers to vent their own frustrations. Participants agree that clear, consensually agreed upon rules should be set to regulate school behaviour and that there should be clear and consensually agreed upon ways of ensuring that these rules are adhered to; and constructive ways of dealing with violation of these rules. The central concern seems to be to move away from a retributive, punitive mode of thinking about punishment, towards a purposeful one. The implications of the research findings are discussed in the context of existing literature in the area and in relation to policy development.
- Full Text:
- Date Issued: 1997
- Authors: Sedumedi, Susan Dimakatso
- Date: 1997
- Subjects: Punishment -- South Africa , Discipline of children -- Psychological aspects , Discipline of children -- South Africa , High school teachers -- South Africa -- Attitudes , High school students -- South Africa -- Attitudes , Parents -- South Africa -- Attitudes , Corporal punishment , Corporal punishment -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3051 , http://hdl.handle.net/10962/d1002560 , Punishment -- South Africa , Discipline of children -- Psychological aspects , Discipline of children -- South Africa , High school teachers -- South Africa -- Attitudes , High school students -- South Africa -- Attitudes , Parents -- South Africa -- Attitudes , Corporal punishment , Corporal punishment -- South Africa
- Description: While some research has been done on the use of corporal punishment in South African schools, there is a dearth of research on other forms of punishment and little has been done to research the meaning of punishment. This study explores the meaning of punishment in a high school context and focuses on the different attitudes of parents, teachers and pupils, with a view to identifying, in particular, how they justify the use of punishment. A sample of 50 pupils, 30 teachers and 30 parents were selected for the study. Focus groups and a questionnaire with closed and open-ended questions were used to collect the data. The questionnaire was constructed to explore themes which emerged in the focus group discussions . Results were grouped into themes and arranged by tables , and the Chi-square test of statistical significance was used to analyze some of the data. The results show that the meaning and the approach to punishment is differently construed by participants. Parents construe punishment as an educative instrument and a disciplinary measure used for the good of pupils and the society. Teachers see it as a discip1inary measure, a strategy used for effective learning, and a negative stimulus used to inflict pain towards the goal of an orderly school environment. To pupils the punishment scene provides an opportunity for what they perceive as sadistic enjoyment and as something negative which is used by teachers to vent their own frustrations. Participants agree that clear, consensually agreed upon rules should be set to regulate school behaviour and that there should be clear and consensually agreed upon ways of ensuring that these rules are adhered to; and constructive ways of dealing with violation of these rules. The central concern seems to be to move away from a retributive, punitive mode of thinking about punishment, towards a purposeful one. The implications of the research findings are discussed in the context of existing literature in the area and in relation to policy development.
- Full Text:
- Date Issued: 1997
Qonqonqo
- Group performance, Group composition, Dargie, Dave
- Authors: Group performance , Group composition , Dargie, Dave
- Date: 1997
- Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
- Language: IsiXhosa
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/343550 , vital:63022 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC346b-01
- Description: Church music
- Full Text: false
- Date Issued: 1997
- Authors: Group performance , Group composition , Dargie, Dave
- Date: 1997
- Subjects: Folk music , Sacred music , Field recordings , Africa, Sub-Saharan , Africa South Africa Hogsback sa
- Language: IsiXhosa
- Type: sound recordings , field recordings , sound recording-musical
- Identifier: http://hdl.handle.net/10962/343550 , vital:63022 , International Library of African Music, Rhodes University, Makhanda, South Africa , Dave Dargie Field Tapes, Rhodes University, Makhanda, South Africa , DDC346b-01
- Description: Church music
- Full Text: false
- Date Issued: 1997
Radio observation of the Gum Nebula Region
- Authors: Woermann, Beate
- Date: 1997
- Subjects: Radio sources (Astronomy) Nebulae -- Observations Radio astronomy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5485 , http://hdl.handle.net/10962/d1005271
- Description: This thesis describes the results of an investigation of the physical properties of the Gum Nebula. For this investigation a radio continuum map of the region was made at 2326 MHz and resolution ⅓° with the HartRAO antenna. This map was used to generate spectral index images and an infrared to radio flux density ratio (IRR) image. The latter image shows that the IRR of the nebula is in the range 20 to 250, identifying it as an old SNR. Several spectral index images of this region were generated using two different methods, one based on the isolation of the nebula from its background radiation, the other based on TT-plots (Turtle et al., 1962). The two methods yield similar results, which show that the nebula has a thermal shell with a non-thermal region in its interior. Below the galactic plane the thermal region dominates and above the plane the nonthermal region. These results suggest a model of an old SNR with an H II region shell. Spectral line observations of hydrogen recombination lines and hydroxyl (OH) were made with the HartRAO and the Mopra telescopes. The detection of hydrogen recombination lines at four positions in the thermal regions of the nebula give electron temperatures and emission measures in the ranges 4000 to 6000 K and 220 to 460 pc.cm⁻⁶ respectively. The turbulent velocities are of the order of 20 km/s. A search for shocked OH lines at 1667 MHz and 1720 MHz in the Gum Nebula gave results that were negative, but numerous unshocked 1667 MHz OH lines were detected. The latter were used in a test for an expansion of the nebula. The most plausible fit to the data gives an expansion centre at l = 260.5°, b = -2.5° and at a distance of 0.7 kpc from us. The front face angular radius and expansion velocity are 10.5° and 16 km/s respectively. The back face angular radius and expansion velocity are 8.50 and 7 km/s respectively.
- Full Text:
- Date Issued: 1997
- Authors: Woermann, Beate
- Date: 1997
- Subjects: Radio sources (Astronomy) Nebulae -- Observations Radio astronomy
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5485 , http://hdl.handle.net/10962/d1005271
- Description: This thesis describes the results of an investigation of the physical properties of the Gum Nebula. For this investigation a radio continuum map of the region was made at 2326 MHz and resolution ⅓° with the HartRAO antenna. This map was used to generate spectral index images and an infrared to radio flux density ratio (IRR) image. The latter image shows that the IRR of the nebula is in the range 20 to 250, identifying it as an old SNR. Several spectral index images of this region were generated using two different methods, one based on the isolation of the nebula from its background radiation, the other based on TT-plots (Turtle et al., 1962). The two methods yield similar results, which show that the nebula has a thermal shell with a non-thermal region in its interior. Below the galactic plane the thermal region dominates and above the plane the nonthermal region. These results suggest a model of an old SNR with an H II region shell. Spectral line observations of hydrogen recombination lines and hydroxyl (OH) were made with the HartRAO and the Mopra telescopes. The detection of hydrogen recombination lines at four positions in the thermal regions of the nebula give electron temperatures and emission measures in the ranges 4000 to 6000 K and 220 to 460 pc.cm⁻⁶ respectively. The turbulent velocities are of the order of 20 km/s. A search for shocked OH lines at 1667 MHz and 1720 MHz in the Gum Nebula gave results that were negative, but numerous unshocked 1667 MHz OH lines were detected. The latter were used in a test for an expansion of the nebula. The most plausible fit to the data gives an expansion centre at l = 260.5°, b = -2.5° and at a distance of 0.7 kpc from us. The front face angular radius and expansion velocity are 10.5° and 16 km/s respectively. The back face angular radius and expansion velocity are 8.50 and 7 km/s respectively.
- Full Text:
- Date Issued: 1997
Redescription of three species of the genus Platypleura Amyot and Serville 1843 (Hemiptera Cicadidae)
- Authors: Villet, Martin H
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453827 , vital:75290 , https://doi.org/10.1080/03946975.1997.10539345
- Description: The type material of three platypleurine cicadas described by GERMAR (1834), Platypleura divisa, P. hirtipennis and P. plumosa, have been rediscovered and are redescribed to clarify their identity. Notes on their biology and biogeography are included.
- Full Text:
- Date Issued: 1997
- Authors: Villet, Martin H
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/453827 , vital:75290 , https://doi.org/10.1080/03946975.1997.10539345
- Description: The type material of three platypleurine cicadas described by GERMAR (1834), Platypleura divisa, P. hirtipennis and P. plumosa, have been rediscovered and are redescribed to clarify their identity. Notes on their biology and biogeography are included.
- Full Text:
- Date Issued: 1997
Reflecting on socially transformative environmental literacy for Lesotho
- Mokuku, Tsepo, Lotz-Sisitka, Heila
- Authors: Mokuku, Tsepo , Lotz-Sisitka, Heila
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438769 , vital:73498 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137444"
- Description: This paper is an attempt to clarify the concept of environmental literacy from a socially transformative orientation. It resulted from our ongoing reflection on a conceptual framework in and for a three-year research project on education for environmental literacy within the integrated science curriculum in Lesotho.
- Full Text:
- Date Issued: 1997
- Authors: Mokuku, Tsepo , Lotz-Sisitka, Heila
- Date: 1997
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438769 , vital:73498 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137444"
- Description: This paper is an attempt to clarify the concept of environmental literacy from a socially transformative orientation. It resulted from our ongoing reflection on a conceptual framework in and for a three-year research project on education for environmental literacy within the integrated science curriculum in Lesotho.
- Full Text:
- Date Issued: 1997
Regional and local economic development strategies in the Eastern Cape and guidelines for future development
- Nel, E L
- Authors: Nel, E L
- Date: 1997
- Subjects: Community development -- South Africa -- Eastern Cape Case studies Community development Community development -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4848 , http://hdl.handle.net/10962/d1005524
- Description: Local Economic Development (LED) is an applied economic development strategy which seeks to address site-specific needs through locally appropriate solutions. In this thesis, the faith being accorded to the potential of LED in South Africa is critically examined. The study is based on a detailed examination of the experience of regional development and several emerging cases of LED in the Eastern Cape Province of South Africa. High levels of poverty and unemployment necessitate and justify innovative approaches to address such problems. The thesis examines the potential of LED strategies and identifies applied policy guidelines which can help address the Province's development needs. The theoretical framework of this research is based on a critical examination of international and South African literature dealing with development issues, LED and localities theory. A detailed documentary examination of early LED endeavours and the experience of regional development in the present century was undertaken. Results suggest that LED is not a new concept and that regional development, through its political bias, achieved only limited success. Contemporary examples of LED were identified and examined through detailed site-specific investigations. This was carried out through the use of semistructured interviews supplemented by participatory rural appraisal and questionnaire surveys which served as a means to triangulate the results. The research findings indicate that regional development, as applied in the study area, did not lead to the establishment of a permanent industrial base. In terms of the concept of LED, it is apparent that it has allowed for socio-political empowerment but has only improved economic conditions in the more well-endowed case-studies. In these areas, positive antecedent conditions and the key role played by community supportive nongovernmental organizations is apparent. Despite the limited degree of success which many initiatives attain, the thesis regards LED as a development alternative for areas which are unlikely to draw in external investment. Some of the key contributions of the thesis include the advancement of a refined typology of LED, the development of a research schedule to investigate and assess LED initiatives and the postulation of appropriate development guidelines and theoretical constructs.
- Full Text:
- Date Issued: 1997
- Authors: Nel, E L
- Date: 1997
- Subjects: Community development -- South Africa -- Eastern Cape Case studies Community development Community development -- South Africa -- Eastern Cape Eastern Cape (South Africa) -- Economic conditions
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4848 , http://hdl.handle.net/10962/d1005524
- Description: Local Economic Development (LED) is an applied economic development strategy which seeks to address site-specific needs through locally appropriate solutions. In this thesis, the faith being accorded to the potential of LED in South Africa is critically examined. The study is based on a detailed examination of the experience of regional development and several emerging cases of LED in the Eastern Cape Province of South Africa. High levels of poverty and unemployment necessitate and justify innovative approaches to address such problems. The thesis examines the potential of LED strategies and identifies applied policy guidelines which can help address the Province's development needs. The theoretical framework of this research is based on a critical examination of international and South African literature dealing with development issues, LED and localities theory. A detailed documentary examination of early LED endeavours and the experience of regional development in the present century was undertaken. Results suggest that LED is not a new concept and that regional development, through its political bias, achieved only limited success. Contemporary examples of LED were identified and examined through detailed site-specific investigations. This was carried out through the use of semistructured interviews supplemented by participatory rural appraisal and questionnaire surveys which served as a means to triangulate the results. The research findings indicate that regional development, as applied in the study area, did not lead to the establishment of a permanent industrial base. In terms of the concept of LED, it is apparent that it has allowed for socio-political empowerment but has only improved economic conditions in the more well-endowed case-studies. In these areas, positive antecedent conditions and the key role played by community supportive nongovernmental organizations is apparent. Despite the limited degree of success which many initiatives attain, the thesis regards LED as a development alternative for areas which are unlikely to draw in external investment. Some of the key contributions of the thesis include the advancement of a refined typology of LED, the development of a research schedule to investigate and assess LED initiatives and the postulation of appropriate development guidelines and theoretical constructs.
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- Date Issued: 1997