Challenging geography: a South African perspective
- Irwin, Patrick R, van Harmelen, Ursula
- Authors: Irwin, Patrick R , van Harmelen, Ursula
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450132 , vital:74885 , https://search.informit.org/doi/abs/10.3316/ielapa.960403836
- Description: Few teachers and learners have any 'sense of ownership' of 'the place' in which school geography is located. Notwithstand-ing the apparent neutrality of a subject that is concerned with information about climate, settlement, or the economy, these 'geographies' have until now been located, in a political and physical landscape of a South Africa that did not 'belong' to the people at large. This has effectively meant that geography has been taught from a perspective that is perceived to be alien and even hostile, and is therefore often considered to be irrel-evant. Teaching resources and strategies have served to strengthen this sense of alienation. Textbooks are, in style and content, almost exclusively situated in a white South Africa of which many pupils have little or no experience. Furthermore, because geography has been taught 'from a book' with field-work the exception rather than the rule, few children have any concept of geography as' that which is all around us' (Mapha-phuli 1992; King 1994). It is part of the missed opportunities of South African geography that indigenous cultural concepts re-lating to the notion of place have not been widely recognised. The combination of a lack of a sense of political ownership and perceived 'eurocentricity' has had a further impact on the atti-tudes of pupils and learners.
- Full Text:
- Date Issued: 1995
- Authors: Irwin, Patrick R , van Harmelen, Ursula
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/450132 , vital:74885 , https://search.informit.org/doi/abs/10.3316/ielapa.960403836
- Description: Few teachers and learners have any 'sense of ownership' of 'the place' in which school geography is located. Notwithstand-ing the apparent neutrality of a subject that is concerned with information about climate, settlement, or the economy, these 'geographies' have until now been located, in a political and physical landscape of a South Africa that did not 'belong' to the people at large. This has effectively meant that geography has been taught from a perspective that is perceived to be alien and even hostile, and is therefore often considered to be irrel-evant. Teaching resources and strategies have served to strengthen this sense of alienation. Textbooks are, in style and content, almost exclusively situated in a white South Africa of which many pupils have little or no experience. Furthermore, because geography has been taught 'from a book' with field-work the exception rather than the rule, few children have any concept of geography as' that which is all around us' (Mapha-phuli 1992; King 1994). It is part of the missed opportunities of South African geography that indigenous cultural concepts re-lating to the notion of place have not been widely recognised. The combination of a lack of a sense of political ownership and perceived 'eurocentricity' has had a further impact on the atti-tudes of pupils and learners.
- Full Text:
- Date Issued: 1995
Characterisation of the genome of Nudaurelia Omega Virus
- Authors: Cox, Dermot
- Date: 1995
- Subjects: Imbrasia cytherea , RNA , Insects -- Viruses
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4023 , http://hdl.handle.net/10962/d1004083 , Imbrasia cytherea , RNA , Insects -- Viruses
- Description: Nudaurelia co virus (Nco V) is a small RNA virus belonging to the Family Tetraviridae. Nco V was successfully isolated from field collected larvae of the pine emperor moth, Nudaurelia cytherea capensis. By polyacrylamide gel electrophoresis-it was possible Jo determine the size of the capsid proteins. Anti-NcoV antiserum was raised by inoculating a rabbit with purified virus. RNA was extracted from the purified virus using a phenol\chloroform extraction procedure. It was possible to separate the viral RNA into its constituent species using sucrose density gradient centrifugation. The sizes of both species of RNA was accurately determined by agarose gel electrophoresis. These sizes corresponded to the replicative form of the RNA which was extracted from infected host tissue. The absence of a poly(A) tract on the RNA was shown through poly(U) sepharose chromatography. Cell-free translation of the viral RNA elucidated the sizes of proteins encoded in vitro in a rabbit reticulocyte lysate system. Optimal conditions for in vitro translation of Nco V were determined for a range of conditions. Immunoprecipitaion of viral encoded proteins with anti-Nco V antiserum suggested that the putative coat protein of the virus was encoded by RNA 2, as a precursor polypeptide which underwent posttranslational cleavage. Reverse transcription - polymerase chain reaction (RT -PCR) was used to successfully produce a radiolabelled probe which could detect dot-blotted viral RNA. The efficacy of this probe in detecting the presence of Nco V RNA in infected tissue was also tested.
- Full Text:
- Date Issued: 1995
- Authors: Cox, Dermot
- Date: 1995
- Subjects: Imbrasia cytherea , RNA , Insects -- Viruses
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4023 , http://hdl.handle.net/10962/d1004083 , Imbrasia cytherea , RNA , Insects -- Viruses
- Description: Nudaurelia co virus (Nco V) is a small RNA virus belonging to the Family Tetraviridae. Nco V was successfully isolated from field collected larvae of the pine emperor moth, Nudaurelia cytherea capensis. By polyacrylamide gel electrophoresis-it was possible Jo determine the size of the capsid proteins. Anti-NcoV antiserum was raised by inoculating a rabbit with purified virus. RNA was extracted from the purified virus using a phenol\chloroform extraction procedure. It was possible to separate the viral RNA into its constituent species using sucrose density gradient centrifugation. The sizes of both species of RNA was accurately determined by agarose gel electrophoresis. These sizes corresponded to the replicative form of the RNA which was extracted from infected host tissue. The absence of a poly(A) tract on the RNA was shown through poly(U) sepharose chromatography. Cell-free translation of the viral RNA elucidated the sizes of proteins encoded in vitro in a rabbit reticulocyte lysate system. Optimal conditions for in vitro translation of Nco V were determined for a range of conditions. Immunoprecipitaion of viral encoded proteins with anti-Nco V antiserum suggested that the putative coat protein of the virus was encoded by RNA 2, as a precursor polypeptide which underwent posttranslational cleavage. Reverse transcription - polymerase chain reaction (RT -PCR) was used to successfully produce a radiolabelled probe which could detect dot-blotted viral RNA. The efficacy of this probe in detecting the presence of Nco V RNA in infected tissue was also tested.
- Full Text:
- Date Issued: 1995
Community policing : tentative steps towards true reconciliation : inaugural lecture delivered at Rhodes University
- Authors: Midgley, J R
- Date: 1995
- Subjects: National Peace Accord, 1991 , Volunteer workers in law enforcement -- South Africa , Police -- South Africa
- Language: English
- Type: Text
- Identifier: vital:654 , http://hdl.handle.net/10962/d1020723 , ISBN 0868102962
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1995
- Authors: Midgley, J R
- Date: 1995
- Subjects: National Peace Accord, 1991 , Volunteer workers in law enforcement -- South Africa , Police -- South Africa
- Language: English
- Type: Text
- Identifier: vital:654 , http://hdl.handle.net/10962/d1020723 , ISBN 0868102962
- Description: Inaugural lecture delivered at Rhodes University , Rhodes University Libraries (Digitisation)
- Full Text:
- Date Issued: 1995
Complex interactions involving the Cape fig, Ficus sur Forsskål, and its associated insects
- Authors: Zachariades, Costas
- Date: 1995
- Subjects: Insect-plant relationships Mutualism (Biology) Fig -- South Africa Fig wasp -- South Africa Ants Homoptera
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5655 , http://hdl.handle.net/10962/d1005338
- Description: The inadequacy of arbitrarily classifying interactions between species as antagonistic, neutral or mutualistic has become clear in recent years. Both direct and indirect interactions between species can vary between mutualism and antagonism, depending on the intrinsic and extrinsic contexts of the interaction. This study investigated the characteristics of an ant-plant-homopteran interaction in southern Africa. The polyphagous homopteran Hilda patruelis (Tettigometridae) feeds primarily on the trunk-borne fruiting branches and figs of the Cape fig tree, Ficus sur, and produces honeydew which attracts tending ants. Ten of the sixteen ant species/species groups present on F. sur tended H. patruelis, with Pheidole megacephala the most frequent attendant. Ants attracted to F. sur by H. patruelis honeydew or other liquid food sources also preyed on insects on the tree, including adults of the small agaonid fig wasps whose larvae feed on the ovules in the developing figs. One fig wasp species (Ceratosolen capensis) is also the tree's only pollinator. No benefits to H. patruelis from being tended by ants were detected, either in terms of reduced parasitism, or predation by a lycaenid caterpillar. A P. megacephala colony foraging on a F. sur tree was found to receive a high proportion of its likely energy requirements from the tree, mainly in the form of H. patruelis honeydew, during periods when it was bearing fruit. It is probable that the H. patruelis-P. megacephala interaction constitutes a direct mutualism at times, but that benefits to the homopteran are intermittent or weak. Both H. patruelis and ants benefitted from F. sur, directly or indirectly, through the provision of food (and for some ants, nesting sites). The removal of phloem sap by H. patruelis did not detectably reduce the trees' reproductive output, either in terms of pollinator or viable seed production. The indirect effects of ant and H. patruelis presence on the F. sur trees were on average positive, as ants preyed disproportionately heavily on fig wasp species parasitic on or competing with the pollinator, thus increasing pollinator production. Effects of ant presence on seed production were not investigated, but have been demonstrated as beneficial elsewhere. However, there is great varatlon both in the composition of the wasp fauna arriving to oviposit at different crops, and in ant densities per fig, on several temporal and spatial scales. This results in high variability in the effects of ants on the pollinator and, through it, the tree, from positive to zero and potentially even negative. Despite this conditionality of beneficial outcomes for the tree, the mean effect of ants on the F. sur population studied was to increase pollinator production by up to nearly 20%. This study is among the few to have demonstrated an overall benefit to a plant of having homopteran-tending ants present on it.
- Full Text:
- Date Issued: 1995
- Authors: Zachariades, Costas
- Date: 1995
- Subjects: Insect-plant relationships Mutualism (Biology) Fig -- South Africa Fig wasp -- South Africa Ants Homoptera
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5655 , http://hdl.handle.net/10962/d1005338
- Description: The inadequacy of arbitrarily classifying interactions between species as antagonistic, neutral or mutualistic has become clear in recent years. Both direct and indirect interactions between species can vary between mutualism and antagonism, depending on the intrinsic and extrinsic contexts of the interaction. This study investigated the characteristics of an ant-plant-homopteran interaction in southern Africa. The polyphagous homopteran Hilda patruelis (Tettigometridae) feeds primarily on the trunk-borne fruiting branches and figs of the Cape fig tree, Ficus sur, and produces honeydew which attracts tending ants. Ten of the sixteen ant species/species groups present on F. sur tended H. patruelis, with Pheidole megacephala the most frequent attendant. Ants attracted to F. sur by H. patruelis honeydew or other liquid food sources also preyed on insects on the tree, including adults of the small agaonid fig wasps whose larvae feed on the ovules in the developing figs. One fig wasp species (Ceratosolen capensis) is also the tree's only pollinator. No benefits to H. patruelis from being tended by ants were detected, either in terms of reduced parasitism, or predation by a lycaenid caterpillar. A P. megacephala colony foraging on a F. sur tree was found to receive a high proportion of its likely energy requirements from the tree, mainly in the form of H. patruelis honeydew, during periods when it was bearing fruit. It is probable that the H. patruelis-P. megacephala interaction constitutes a direct mutualism at times, but that benefits to the homopteran are intermittent or weak. Both H. patruelis and ants benefitted from F. sur, directly or indirectly, through the provision of food (and for some ants, nesting sites). The removal of phloem sap by H. patruelis did not detectably reduce the trees' reproductive output, either in terms of pollinator or viable seed production. The indirect effects of ant and H. patruelis presence on the F. sur trees were on average positive, as ants preyed disproportionately heavily on fig wasp species parasitic on or competing with the pollinator, thus increasing pollinator production. Effects of ant presence on seed production were not investigated, but have been demonstrated as beneficial elsewhere. However, there is great varatlon both in the composition of the wasp fauna arriving to oviposit at different crops, and in ant densities per fig, on several temporal and spatial scales. This results in high variability in the effects of ants on the pollinator and, through it, the tree, from positive to zero and potentially even negative. Despite this conditionality of beneficial outcomes for the tree, the mean effect of ants on the F. sur population studied was to increase pollinator production by up to nearly 20%. This study is among the few to have demonstrated an overall benefit to a plant of having homopteran-tending ants present on it.
- Full Text:
- Date Issued: 1995
Comprehending strike action: the South African experience c.1950-1990 and the theoretical implications thereof
- Authors: Wood, Geoffrey Thomas
- Date: 1995
- Subjects: Strikes and lockouts -- South Africa -- History Industrial relations -- South Africa -- History Labor unions -- South Africa -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3319 , http://hdl.handle.net/10962/d1003107
- Description: Regular strike action has become a central characteristic of the South African industrial relations system. Whilst in the 1950s strikes were mostly isolated outbursts of relatively short duration, strikes in the 1980s were challenges of unprecedented duration and intensity. It is argued that despite this dramatic change, reflecting a series of discontinuities in both the political and economic arenas, strike action in South Africa does follow distinct patterns, and can be ascribed to a combination of identifiable causes. Principal causal factors include wage aspirations, past experiences and the subjective interpretation thereof, and the role of the union movement. Contingent factors include the prevailing political climate, industrial relations legislation, the amount of information opposing sides possess of their adversaries' intentions as well as spatial issues, such as the internal dynamics of individual communities. Partially as a result of South Africa's political transformation, the late 1980s and early 1990s saw further changes in the industrial relations environment. Reflecting these developments, it is argued that a new type of trade unionism has developed, "coterminous unionism" . This will have far-reaching implications for the nature of industrial conflict. However, it falls fully within the theoretical parameters outlined in this thesis. Despite significant developments in social theory in the 1980s and 1990s, there have been few attempts accordingly to update theories of strike action. One of the objectives of this thesis has been to attempt such an update. It is hoped that the constructs developed will shed light on a widely prevalent form of social conflict, assist in the analysis of future outbreaks, and enable the identification of those situations where a high propensity to engage in strike action may exist.
- Full Text:
- Date Issued: 1995
- Authors: Wood, Geoffrey Thomas
- Date: 1995
- Subjects: Strikes and lockouts -- South Africa -- History Industrial relations -- South Africa -- History Labor unions -- South Africa -- History
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3319 , http://hdl.handle.net/10962/d1003107
- Description: Regular strike action has become a central characteristic of the South African industrial relations system. Whilst in the 1950s strikes were mostly isolated outbursts of relatively short duration, strikes in the 1980s were challenges of unprecedented duration and intensity. It is argued that despite this dramatic change, reflecting a series of discontinuities in both the political and economic arenas, strike action in South Africa does follow distinct patterns, and can be ascribed to a combination of identifiable causes. Principal causal factors include wage aspirations, past experiences and the subjective interpretation thereof, and the role of the union movement. Contingent factors include the prevailing political climate, industrial relations legislation, the amount of information opposing sides possess of their adversaries' intentions as well as spatial issues, such as the internal dynamics of individual communities. Partially as a result of South Africa's political transformation, the late 1980s and early 1990s saw further changes in the industrial relations environment. Reflecting these developments, it is argued that a new type of trade unionism has developed, "coterminous unionism" . This will have far-reaching implications for the nature of industrial conflict. However, it falls fully within the theoretical parameters outlined in this thesis. Despite significant developments in social theory in the 1980s and 1990s, there have been few attempts accordingly to update theories of strike action. One of the objectives of this thesis has been to attempt such an update. It is hoped that the constructs developed will shed light on a widely prevalent form of social conflict, assist in the analysis of future outbreaks, and enable the identification of those situations where a high propensity to engage in strike action may exist.
- Full Text:
- Date Issued: 1995
Confrontation, cooptation and collaboration : the response and reaction of the Labour Party of South Africa to Government Policy, 1965-1984
- Authors: Du Pré, Roy Howard
- Date: 1995
- Subjects: South African Labour Party -- History Colored people (South Africa) -- Politics and government South Africa -- Politics and government -- 1948-1994
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2539 , http://hdl.handle.net/10962/d1002391
- Description: The Labour Party was a prominent political party amongst coloured people for more than twenty-five years. Formed in 1965 to contest elections for the Coloured Persons' Representative Council (CRC), the Labour Party at the outset adopted an anti-apartheid, anti-separate representation and anti-eRe stance. During the first five years of its existence, the party tried to muster coloured support for its policies. Its promise to cripple the CRC by refusing to occupy seats in the council became the rallying call. The Labour Party won a majority of the elected seats in the first CRC election in 1969 but the government nominated progovernment candidates to all the nominated seats, depriving the Labour Party of an overall majority. Thwarted in their bid to "wreck" the CRC, Labour Party members instead took their seats in the council, vowing to destroy it from within. For the next five years the Labour Party pursued a policy of "confrontation. " By using a "boycott" strategy, it not only hamstrung the effective working of the CRC but thwarted the government in other areas of its "coloured" policy. In the 1975 election the Labour Party won an outright victory, giving it the power to cripple the CRC. However, it did not seize this opportunity. Its decision to "govern" in the CRC constituted a decisive step in the change from confrontation to cooptation. The Labour Party's continued support of the CRC drew widespread criticism from supporters and opponents alike. Its leaders tried to hold together a disaffected party and eventually agreed to the dissolution of the CRC in 1980 in an effort to paper over the cracks in party unity, and to forestall growing coloured opposition to the CRC at the next election. In 1983, the Labour Party displayed a decisive shift in its anti-separate representation stance by lending support to the tricameral system. By doing so, it laid itself open to the same charge of collaboration it had levelled at the other CRC parties. This thesis will examine the history of the Labour Party from its formation in 1965 as an anti-government party, to one of cooperation with its erstwhile opponent by 1984.
- Full Text:
- Date Issued: 1995
- Authors: Du Pré, Roy Howard
- Date: 1995
- Subjects: South African Labour Party -- History Colored people (South Africa) -- Politics and government South Africa -- Politics and government -- 1948-1994
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2539 , http://hdl.handle.net/10962/d1002391
- Description: The Labour Party was a prominent political party amongst coloured people for more than twenty-five years. Formed in 1965 to contest elections for the Coloured Persons' Representative Council (CRC), the Labour Party at the outset adopted an anti-apartheid, anti-separate representation and anti-eRe stance. During the first five years of its existence, the party tried to muster coloured support for its policies. Its promise to cripple the CRC by refusing to occupy seats in the council became the rallying call. The Labour Party won a majority of the elected seats in the first CRC election in 1969 but the government nominated progovernment candidates to all the nominated seats, depriving the Labour Party of an overall majority. Thwarted in their bid to "wreck" the CRC, Labour Party members instead took their seats in the council, vowing to destroy it from within. For the next five years the Labour Party pursued a policy of "confrontation. " By using a "boycott" strategy, it not only hamstrung the effective working of the CRC but thwarted the government in other areas of its "coloured" policy. In the 1975 election the Labour Party won an outright victory, giving it the power to cripple the CRC. However, it did not seize this opportunity. Its decision to "govern" in the CRC constituted a decisive step in the change from confrontation to cooptation. The Labour Party's continued support of the CRC drew widespread criticism from supporters and opponents alike. Its leaders tried to hold together a disaffected party and eventually agreed to the dissolution of the CRC in 1980 in an effort to paper over the cracks in party unity, and to forestall growing coloured opposition to the CRC at the next election. In 1983, the Labour Party displayed a decisive shift in its anti-separate representation stance by lending support to the tricameral system. By doing so, it laid itself open to the same charge of collaboration it had levelled at the other CRC parties. This thesis will examine the history of the Labour Party from its formation in 1965 as an anti-government party, to one of cooperation with its erstwhile opponent by 1984.
- Full Text:
- Date Issued: 1995
Constituent processes contributing to stress induced β-carotene accumulation in Dunaliella salina
- Authors: Phillips, Lesley Gail
- Date: 1995
- Subjects: Dunaliella Carotenes Plants -- Effect of stress on
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5658 , http://hdl.handle.net/10962/d1005341
- Description: The alga Dunaliella salina possesses the unique ability to accumulate up to 14 % of it's dry weight as β-carotene in response to stress conditions. This hyper-accumulation of β-carotene has led to the commercial exploitation of this alga for the biotechnological production of this important carotenoid. In order to maximise β-carotene production, a dual-stage process which separates the distinctive growth phase from the β-carotene accumulating stress phase has recently been patented. Preliminary laboratory studies showed that although stress factors such as high salinity and nutrient limitation enhance β-carotene accumulation in D. salina (± 10 pg.cell⁻¹), high light intensity was the single most important factor contributing to the induction of β-carotene accumulation in this alga (± 20 pg.cell⁻¹). Moreover, it was demonstrated that β-carotene accumulation can be further stimulated by exposing the alga to a combination of high light intensity, salt and nutrient stresses (± 30-60 pg.cell⁻¹). The response of D. salina to stress was shown to occur in two phases. The first phase occurred within 24 hours and was characterized most importantly by higher rates of β-carotene accumulation for all the stresses investigated. In cells exposed to multiple stress factors in mass culture, the β-carotene accumulation rate was as much as 9.5 pg.cell⁻¹.day⁻¹ in the first phase compared to only 3 pg.cell·day⁻¹ in the second phase. Since the rate of β-carotene accumulation was higher within the first 24 hours after exposure to stress, the first phase was considered crucial for stress-induced β-carotene accumulation. Characterization of this phase revealed that the stress response was multifaceted. Transition of cells from the growth stage to stress conditions was characterized by the following: 1) Change in cell volume. Hypersalinity caused cell shrinkage while cells exposed to nutrient limitation and/or high light intensity caused cells to swell. Restoration of cell volume was shown to occur within 8 hours for all stresses investigated. 2) Altered photosynthesis. Inhibition of both carbon fixation and oxygen evolution was demonstrated in cells immediately after exposure to multiple stress factors. 3) Production of abscisic acid. Intracellular ABA levels increased within 6-8 hours after exposure to all stresses investigated. The rise in intracellular ABA levels coincided with an increase or return to starting cell volume. High intracellular ABA levels were however transient and within 24 hours ABA began to partition into the culture medium. 4) Change in pigment composition. Changes in xanthophyll cycle pigment content was demonstrated soon after exposure to stress conditions. In hypersalinity shocked cells, initial epoxidation of zeaxanthin to violaxanthin and subsequent de-epoxidation to zeaxanthin occurred, whereas exposure to high stress resulted in an immediate and continued decrease in the epoxidation state indicating accumulation of zeaxanthin. A rapid rate of chlorophyll depletion was also demonstrated. In addition to the above responses a rapid decrease in growth rate during this phase was also noted. An interrelationship between cell volume change, ABA production, maintenance of xanthophyll cycle operation and β-carotene accumulation therefore appeared to exist. ABA production was shown to be stoichiometrically related to changes in xanthophyll content with r² = 0.84 and slope of the curve = 0.91 being achieved for high light stressed cells. This study therefore presents strong circumstantial evidence in support of a carotenoid origin for ABA in Dunaliella. In addition, enhanced β-carotene content was achieved by the application of exogenous ABA and related compounds suggesting a role for ABA as a regulator of the overall stress response. Furthermore, zeaxanthin accumulation was shown to be positively correlated ( r²≥ 0.81) to β-carotene accumulation for all the stresses investigated. The second phase was characterized by a return to homoeostasis of the physiological processes mentioned above, indicating acclimation of the cell to prevailing conditions. This stage was characterised by continued β-carotene accumulation and a decreased epoxidation state of the xanthophyll cycle which together appeared to sustain photosynthesis, allowing this organism to tolerate stress conditions.
- Full Text:
- Date Issued: 1995
- Authors: Phillips, Lesley Gail
- Date: 1995
- Subjects: Dunaliella Carotenes Plants -- Effect of stress on
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5658 , http://hdl.handle.net/10962/d1005341
- Description: The alga Dunaliella salina possesses the unique ability to accumulate up to 14 % of it's dry weight as β-carotene in response to stress conditions. This hyper-accumulation of β-carotene has led to the commercial exploitation of this alga for the biotechnological production of this important carotenoid. In order to maximise β-carotene production, a dual-stage process which separates the distinctive growth phase from the β-carotene accumulating stress phase has recently been patented. Preliminary laboratory studies showed that although stress factors such as high salinity and nutrient limitation enhance β-carotene accumulation in D. salina (± 10 pg.cell⁻¹), high light intensity was the single most important factor contributing to the induction of β-carotene accumulation in this alga (± 20 pg.cell⁻¹). Moreover, it was demonstrated that β-carotene accumulation can be further stimulated by exposing the alga to a combination of high light intensity, salt and nutrient stresses (± 30-60 pg.cell⁻¹). The response of D. salina to stress was shown to occur in two phases. The first phase occurred within 24 hours and was characterized most importantly by higher rates of β-carotene accumulation for all the stresses investigated. In cells exposed to multiple stress factors in mass culture, the β-carotene accumulation rate was as much as 9.5 pg.cell⁻¹.day⁻¹ in the first phase compared to only 3 pg.cell·day⁻¹ in the second phase. Since the rate of β-carotene accumulation was higher within the first 24 hours after exposure to stress, the first phase was considered crucial for stress-induced β-carotene accumulation. Characterization of this phase revealed that the stress response was multifaceted. Transition of cells from the growth stage to stress conditions was characterized by the following: 1) Change in cell volume. Hypersalinity caused cell shrinkage while cells exposed to nutrient limitation and/or high light intensity caused cells to swell. Restoration of cell volume was shown to occur within 8 hours for all stresses investigated. 2) Altered photosynthesis. Inhibition of both carbon fixation and oxygen evolution was demonstrated in cells immediately after exposure to multiple stress factors. 3) Production of abscisic acid. Intracellular ABA levels increased within 6-8 hours after exposure to all stresses investigated. The rise in intracellular ABA levels coincided with an increase or return to starting cell volume. High intracellular ABA levels were however transient and within 24 hours ABA began to partition into the culture medium. 4) Change in pigment composition. Changes in xanthophyll cycle pigment content was demonstrated soon after exposure to stress conditions. In hypersalinity shocked cells, initial epoxidation of zeaxanthin to violaxanthin and subsequent de-epoxidation to zeaxanthin occurred, whereas exposure to high stress resulted in an immediate and continued decrease in the epoxidation state indicating accumulation of zeaxanthin. A rapid rate of chlorophyll depletion was also demonstrated. In addition to the above responses a rapid decrease in growth rate during this phase was also noted. An interrelationship between cell volume change, ABA production, maintenance of xanthophyll cycle operation and β-carotene accumulation therefore appeared to exist. ABA production was shown to be stoichiometrically related to changes in xanthophyll content with r² = 0.84 and slope of the curve = 0.91 being achieved for high light stressed cells. This study therefore presents strong circumstantial evidence in support of a carotenoid origin for ABA in Dunaliella. In addition, enhanced β-carotene content was achieved by the application of exogenous ABA and related compounds suggesting a role for ABA as a regulator of the overall stress response. Furthermore, zeaxanthin accumulation was shown to be positively correlated ( r²≥ 0.81) to β-carotene accumulation for all the stresses investigated. The second phase was characterized by a return to homoeostasis of the physiological processes mentioned above, indicating acclimation of the cell to prevailing conditions. This stage was characterised by continued β-carotene accumulation and a decreased epoxidation state of the xanthophyll cycle which together appeared to sustain photosynthesis, allowing this organism to tolerate stress conditions.
- Full Text:
- Date Issued: 1995
Constitution of the Building Workers Union
- Building Workers Union (BWU)
- Authors: Building Workers Union (BWU)
- Date: 1995
- Subjects: BWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/178651 , vital:42971
- Description: This Trade Union shall be a body corporate with perpetual succession capable of entering into contractual and other relations and of suing and being sued in its own name and shall be an organisation not for gain.
- Full Text:
- Date Issued: 1995
- Authors: Building Workers Union (BWU)
- Date: 1995
- Subjects: BWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/178651 , vital:42971
- Description: This Trade Union shall be a body corporate with perpetual succession capable of entering into contractual and other relations and of suing and being sued in its own name and shall be an organisation not for gain.
- Full Text:
- Date Issued: 1995
Coping in two cultures: an ecological study of mentally ill people and their families in rural South Africa
- Authors: Cumes, Heide Ulrike
- Date: 1995
- Subjects: Mental illness -- South Africa Xhosa (African people) -- Psychology Xhosa (African people) -- Religion Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2958 , http://hdl.handle.net/10962/d1002467
- Description: This study explores severe mental illness in a South African ru~al district, moving, as with a zoom lens, from the macroperspectives of (i) Xhosa culture, and (ii) biomedicine, to the lived experience of the individual. Its methodology, predominantly qualitative, employed anthropological and psychological procedures. The fieldwork (1988-1989)encompassed a three month stay in the village of Msobomvu. Patients continued to be tracked informally until June, 1995. The empirical research has three parts. In part one, the person with a mental illness was contextualized within Xhosa cosmology and social attitudes. The cognitive and social ecologies were tapped through the narratives of high school and university students at different stages of a Western-biased education. Social attitudes regarding mental illness, and confidence in treatment by traditional healers and the hospital, were also evaluated. Traditional attitudes and supernatural beliefs of illness causation persisted in spite of Eurocentric education, with a concurrent increase in the acceptance of Western-type causal explanations commensurate with continued education. Part two considered the the patients in relation to (i) the biomedical framework (the mental and local hospitals), and (ii) their readjustment to the community after hospitalization. Data came from patient charts, interviews with medical staff, and follow-up visits in the villages. Socio-political and economic issues were salient. Part three case-studied people identified by the village residents as having a mental illness. Resources for treatment - traditional healers, mobile clinic, and village health workers - were the focus. The traditional healing system, and biomedicine, were compared for effectiveness, through the course of illness events. While biomedicine was more effective in containing acute psychotic episodes than treatment by the traditional healer, lack of appropriate resources within the biomedical setting had disastrous results for patient compliance and long-term management of the illness, particularly in people with obvious symptoms of bipolar disorder. The mental hospital emerged as an agent of control. While Xhosa culture provided a more tolerant setting for people with a mental illness, the course of severe mental illness was by no means benign, despite research suggesting a more positive outcome for such conditions in the developing world.
- Full Text:
- Date Issued: 1995
- Authors: Cumes, Heide Ulrike
- Date: 1995
- Subjects: Mental illness -- South Africa Xhosa (African people) -- Psychology Xhosa (African people) -- Religion Xhosa (African people) -- Social life and customs
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2958 , http://hdl.handle.net/10962/d1002467
- Description: This study explores severe mental illness in a South African ru~al district, moving, as with a zoom lens, from the macroperspectives of (i) Xhosa culture, and (ii) biomedicine, to the lived experience of the individual. Its methodology, predominantly qualitative, employed anthropological and psychological procedures. The fieldwork (1988-1989)encompassed a three month stay in the village of Msobomvu. Patients continued to be tracked informally until June, 1995. The empirical research has three parts. In part one, the person with a mental illness was contextualized within Xhosa cosmology and social attitudes. The cognitive and social ecologies were tapped through the narratives of high school and university students at different stages of a Western-biased education. Social attitudes regarding mental illness, and confidence in treatment by traditional healers and the hospital, were also evaluated. Traditional attitudes and supernatural beliefs of illness causation persisted in spite of Eurocentric education, with a concurrent increase in the acceptance of Western-type causal explanations commensurate with continued education. Part two considered the the patients in relation to (i) the biomedical framework (the mental and local hospitals), and (ii) their readjustment to the community after hospitalization. Data came from patient charts, interviews with medical staff, and follow-up visits in the villages. Socio-political and economic issues were salient. Part three case-studied people identified by the village residents as having a mental illness. Resources for treatment - traditional healers, mobile clinic, and village health workers - were the focus. The traditional healing system, and biomedicine, were compared for effectiveness, through the course of illness events. While biomedicine was more effective in containing acute psychotic episodes than treatment by the traditional healer, lack of appropriate resources within the biomedical setting had disastrous results for patient compliance and long-term management of the illness, particularly in people with obvious symptoms of bipolar disorder. The mental hospital emerged as an agent of control. While Xhosa culture provided a more tolerant setting for people with a mental illness, the course of severe mental illness was by no means benign, despite research suggesting a more positive outcome for such conditions in the developing world.
- Full Text:
- Date Issued: 1995
COSATU Press Release
- COSATU
- Authors: COSATU
- Date: 1995
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175651 , vital:42603
- Description: COSATU noting the unfolding education crisis within the Western Cape has called for a stayaway of all of its members and supporters in the Western Cape in support of its demand for measures that will guarantee quality public education, should the Provincial Government fail to meet the demands detailed.
- Full Text:
- Date Issued: 1995
- Authors: COSATU
- Date: 1995
- Subjects: COSATU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/175651 , vital:42603
- Description: COSATU noting the unfolding education crisis within the Western Cape has called for a stayaway of all of its members and supporters in the Western Cape in support of its demand for measures that will guarantee quality public education, should the Provincial Government fail to meet the demands detailed.
- Full Text:
- Date Issued: 1995
Description and identification of white grubs (Coleoptera: Scarabaeidae) attacking pineapple crops in South Africa
- Smith, Tamara J, Petty, G, Villet, Martin H
- Authors: Smith, Tamara J , Petty, G , Villet, Martin H
- Date: 1995
- Language: English
- Type: text , Article
- Identifier: vital:6853 , http://hdl.handle.net/10962/d1011134
- Description: Larvae of five species of scarabaeid beetles, Asthenopholis subfasciata Blanchard, Trochalus politus Moser, Macrophylla ciliata Herbst, Congela valida Peringuey and Adoretus ictericus Burmeister, and adults of a sixth species, Heteronychus arator (Fabricius), cause considerable economic damage to the root systems of pineapple plants. The biologies of the species differ, making reliable identification essential. Since no convenient method is available to identify them, both field and laboratory keys are provided for the identification of third instar larvae of the six species, and detailed, illustrated descriptions for confirming their identifications
- Full Text:
- Date Issued: 1995
- Authors: Smith, Tamara J , Petty, G , Villet, Martin H
- Date: 1995
- Language: English
- Type: text , Article
- Identifier: vital:6853 , http://hdl.handle.net/10962/d1011134
- Description: Larvae of five species of scarabaeid beetles, Asthenopholis subfasciata Blanchard, Trochalus politus Moser, Macrophylla ciliata Herbst, Congela valida Peringuey and Adoretus ictericus Burmeister, and adults of a sixth species, Heteronychus arator (Fabricius), cause considerable economic damage to the root systems of pineapple plants. The biologies of the species differ, making reliable identification essential. Since no convenient method is available to identify them, both field and laboratory keys are provided for the identification of third instar larvae of the six species, and detailed, illustrated descriptions for confirming their identifications
- Full Text:
- Date Issued: 1995
Determination of distinctness among citrus cultivars using biochemical and molecular markers
- Authors: Carstens, Karin
- Date: 1995
- Subjects: Citrus fruits -- South Africa , Citrus fruits -- Research -- South Africa , Citrus fruits -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4022 , http://hdl.handle.net/10962/d1004082 , Citrus fruits -- South Africa , Citrus fruits -- Research -- South Africa , Citrus fruits -- Analysis
- Description: Citrus is among the most important fruit crops worlstwide, and therefore the preservation and improvement of citrus germplasm is of the essence. Citrus breeders are often faced with the difficulty of distinguishing between new and existing cultivars because of the ambiguous nature of morphological traits due to environmental influences and error in human judgement. The protection of new varieties is very important to the breeder. New varieties cannot be patented in South Africa, but it can be protected by Plant Breeders' Rights, only if it is genetically distinguishable and significantly different economically from existing varieties. Cultivars in four genera (c. sinensis, C. paradisi, C. grandis and C. reticulata) included in the Citrus Improvement Programme (CIP) or cultivars awaiting recognition of Plant Breeders' Rights by the International Union for the Protection of New Plant Varieties (UPOV) were analyzed with Isoenzymes, Restriction Fragment Length Polymorphism (RFLP) and Random Amplified Polymorphic DNA (RAPD). Five enzyme systems (PGM, PGI, MDH, GOT and IDH) were analyzed and founded to be suitable for grouping together cultivars belonging to the same genera. It was not suited for routine discrimination of cultivars in a particular genus. RFLP studies were conducted on five grapefruit cultivars, using cDNA clones from a genomic library of Rough Lemon. RFLP studies were valuable for the discrimination of closely related cultivars which probably originated from a common ancestor by bud mutations. This technique was, however, abandoned due to its biohazardous nature and replaced by the PeR-based Random Amplified Polymorphic DNA. RAPDs are easy to perform and gave promisin& results which were exploited to reveal polymorphisms between cultivars within the various groups. Although the interpretation of data produced by this method is often suspicious, it is the best method currently available for cultivar identification. It can playa complementary role in the protection of new varieties when classical morphological interpretation of differences is not capable of determining sufficient distinctness for the awarding of Plant Breeders' Rights.
- Full Text:
- Date Issued: 1995
- Authors: Carstens, Karin
- Date: 1995
- Subjects: Citrus fruits -- South Africa , Citrus fruits -- Research -- South Africa , Citrus fruits -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4022 , http://hdl.handle.net/10962/d1004082 , Citrus fruits -- South Africa , Citrus fruits -- Research -- South Africa , Citrus fruits -- Analysis
- Description: Citrus is among the most important fruit crops worlstwide, and therefore the preservation and improvement of citrus germplasm is of the essence. Citrus breeders are often faced with the difficulty of distinguishing between new and existing cultivars because of the ambiguous nature of morphological traits due to environmental influences and error in human judgement. The protection of new varieties is very important to the breeder. New varieties cannot be patented in South Africa, but it can be protected by Plant Breeders' Rights, only if it is genetically distinguishable and significantly different economically from existing varieties. Cultivars in four genera (c. sinensis, C. paradisi, C. grandis and C. reticulata) included in the Citrus Improvement Programme (CIP) or cultivars awaiting recognition of Plant Breeders' Rights by the International Union for the Protection of New Plant Varieties (UPOV) were analyzed with Isoenzymes, Restriction Fragment Length Polymorphism (RFLP) and Random Amplified Polymorphic DNA (RAPD). Five enzyme systems (PGM, PGI, MDH, GOT and IDH) were analyzed and founded to be suitable for grouping together cultivars belonging to the same genera. It was not suited for routine discrimination of cultivars in a particular genus. RFLP studies were conducted on five grapefruit cultivars, using cDNA clones from a genomic library of Rough Lemon. RFLP studies were valuable for the discrimination of closely related cultivars which probably originated from a common ancestor by bud mutations. This technique was, however, abandoned due to its biohazardous nature and replaced by the PeR-based Random Amplified Polymorphic DNA. RAPDs are easy to perform and gave promisin& results which were exploited to reveal polymorphisms between cultivars within the various groups. Although the interpretation of data produced by this method is often suspicious, it is the best method currently available for cultivar identification. It can playa complementary role in the protection of new varieties when classical morphological interpretation of differences is not capable of determining sufficient distinctness for the awarding of Plant Breeders' Rights.
- Full Text:
- Date Issued: 1995
Determining the relationship between the body image of adolescent girls and their academic achievement, social involvement and sport participation : a pilot study
- Authors: Mostert, Petronella Louisa
- Date: 1995
- Subjects: Body image in adolescence Personality and academic achievement Social interaction in adolescence Self-perception in adolescence Teenage girls -- Psychology Academic achievement
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1492 , http://hdl.handle.net/10962/d1003373
- Description: Ever since the earliest times much emphasis has been placed on the physical appearance of women. Particularly in western cultures idealized images of perfection are constantly promoted and the message that comes across in various media outlets is that a woman ought to have a 'perfect' appearance in order to be competent and desirable. This puts a great deal of stress on women and particularly on adolescent girls who are going through a phase of increased sensitivity about their appearance. The literature suggests that people, and women in particular, are fundamentally affected by the way they view their bodies. The body image furthermore has a strong relationship with the self concept, which affects other areas of a person's life such as her academic achievement and her social 'life. Against this background an attempt was made in this study to determine the relationship between the body image of adolescent girls and their academic achievement, their sport participation and their social involvement. The subjects were 180 girls drawn from two rural secondary schools. The survey involved the completion of two questionnaires, namely an adapted form of the Physical Self Subscale of the Tenessee Self Concept Scale (used to determine a score for body image) and a questionnaire on social involvement and sport participation, which was drawn up by the researcher. Biographic data as well as academic scores were gathered from school records. Data was analysed statistically by means of the BMDP Software Version 1990: programme (Sun Unix). Pearson's chi square tests of independence, as well as a one-way analysis of variance with co-variate were carried out. The results reveal that the body image and academic achievement of this group of girls are not significantly correlated. There are, however, significant correlations between the body image and social involvement of these girls, between their body image and sport participation, as well as between their social involvement and sport participation. iv These findings have important implications for"'e"ducation and consideration is given to addressing these issues in schools.
- Full Text:
- Date Issued: 1995
- Authors: Mostert, Petronella Louisa
- Date: 1995
- Subjects: Body image in adolescence Personality and academic achievement Social interaction in adolescence Self-perception in adolescence Teenage girls -- Psychology Academic achievement
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1492 , http://hdl.handle.net/10962/d1003373
- Description: Ever since the earliest times much emphasis has been placed on the physical appearance of women. Particularly in western cultures idealized images of perfection are constantly promoted and the message that comes across in various media outlets is that a woman ought to have a 'perfect' appearance in order to be competent and desirable. This puts a great deal of stress on women and particularly on adolescent girls who are going through a phase of increased sensitivity about their appearance. The literature suggests that people, and women in particular, are fundamentally affected by the way they view their bodies. The body image furthermore has a strong relationship with the self concept, which affects other areas of a person's life such as her academic achievement and her social 'life. Against this background an attempt was made in this study to determine the relationship between the body image of adolescent girls and their academic achievement, their sport participation and their social involvement. The subjects were 180 girls drawn from two rural secondary schools. The survey involved the completion of two questionnaires, namely an adapted form of the Physical Self Subscale of the Tenessee Self Concept Scale (used to determine a score for body image) and a questionnaire on social involvement and sport participation, which was drawn up by the researcher. Biographic data as well as academic scores were gathered from school records. Data was analysed statistically by means of the BMDP Software Version 1990: programme (Sun Unix). Pearson's chi square tests of independence, as well as a one-way analysis of variance with co-variate were carried out. The results reveal that the body image and academic achievement of this group of girls are not significantly correlated. There are, however, significant correlations between the body image and social involvement of these girls, between their body image and sport participation, as well as between their social involvement and sport participation. iv These findings have important implications for"'e"ducation and consideration is given to addressing these issues in schools.
- Full Text:
- Date Issued: 1995
Dispersal, settlement and recruitment : their influence on the population dynamics of intertidal mussels
- Authors: Phillips, Tracey Elizabeth
- Date: 1995
- Subjects: Perna -- South Africa -- Eastern Cape -- Algoa bay Mytilus galloprovincialis -- South Africa -- Eastern Cape -- Algoa bay Mytilidae -- South Africa -- Eastern Cape -- Algoa bay
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5663 , http://hdl.handle.net/10962/d1005347
- Description: Recruitment of planktonic larvae into sedentary benthic populations regulates the population dynamics of marine invertebrates. The processes controlling recruitment, however, are poorly understood, and recruitment remains largely unpredictable, which complicates management of exploited shellfish resources. The mussels Perna perna, Choromytilus meridionalis and Mytilus galloprovincialis, found on the south coast of southern Africa, have planktonic larvae and sedentary adult stages. This thesis examines dispersal, settlement and early post-settlement growth and mortality, and their effect on recruitment and demography of intertidal mussel populations in the region of Algoa Bay on the south coast of southern Africa. Temporal and spatial variation in the body mass, density and size structure of mussels, the distribution of bivalve larvae on plankton grids in the nearshore zone and the distribution of a recently introduced invasive mussel, Mytilus galloprovincialis, were examined between 1989 and 1992. Furthermore, data on hourly or daily changes in wind strength and direction, air and sea surface temperatures and low and high tide levels in the study region, were obtained. There were 3-4 peaks in spawning (characterised by an abrupt decline in weight) and settlement activity annually. These peaks varied in exact timing, intensity and duration between sites and over time. However, at a site, spawning was followed by settlement 4-8 weeks later, and there was a significant (P < 0.05) direct correlation between spawning intensity prior to the appearance of a new cohort and the cohort density (settlement intensity). The stochastic spatial and temporal variation in breeding activity was superimposed on a more general pattern of a higher intensity of spawning and settlement in Algoa Bay than on the open coast, and a higher settlement intensity on coastal sandstone shores than on dune rock shores. Spawning was more frequent in winter and spring, and the probability of spawning and settlement peaked around the spring and autumn equinox, if temperature and wind conditions were suitable. Larval behaviour had little effect on their dispersal in the well-mixed nearshore region. Larvae were passively dispersed by currents, and their dispersal range and direction depended on prevailing winds and local topography. The sharp decline in density of recruit and adult M. galloprovincialis with increasing distance from the point of introduction, showed that some larvae were carried by wind generated currents over moderately long distances (-100 km). However, since most (76 %) M. galloprovincialis recruited within 4 km of the parent population, it is possible that larvae become trapped in small gullies and crevices around rocky shores, and have a limited dispersal range. This could explain the link between local patterns of spawning and settlement. The distribution and abundance of settlers on the shore was influenced by larval behaviour and the availability of settlement, substrata. Larvae preferred to settle primarily on foliose coralline algae and migrate to the adult mussel bed when they were larger (0.60-7 mm), but larvae also settled directly on adult mussels, possibly because the amount of coralline algae was limited. Both direct and secondary settlement were considered to be important in maintaining mussel populations since the rate of settlement was low(generally < 60 000.m-2). Cohort analyses showed that prior to maturity post-settlement growth (- 30 mm in 10 months) and mortality rates (60-100%) were high, but varied. When settlement intensity was low this variability uncoupled the relationship between spawning and recruitment intensity. Multiple regression analysis showed that together reproductive effort (gamete output), settlement intensity, growth and mortality prior to maturity, accounted for 76 % of the variance in recruitment into mature adult populations. The low settlement rate coupled with the short life span of mussels « 3 years), meant that populations underwent marked spatial and temporal variations in structure and abundance as settlement intensity varied, but there were consistent general differences between mussel populations on dune rock and sandstone shores in Algoa Bay and on the open coast. It was concluded from these results that, spawning intensity and post-settlement growth and mortality, rather than dispersal, regulated recruitment and the structure and abundance of intertidal P. perna and C. meridionalis populations along the south coast of southern Africa. On the basis of these results it is recommended that species with limited dispersal, variable recruitment and high natural mortality, such as P. perna, should be conserved by protecting a small part of the population in reserves, and controlling utilisation outside reserves to minimize disturbance to local brood stocks. Furthermore, since the potential for reseeding adjacent exploited areas is limited, several small reserves placed at regular intervals along the coast would be more effective than a single large reserve.
- Full Text:
- Date Issued: 1995
- Authors: Phillips, Tracey Elizabeth
- Date: 1995
- Subjects: Perna -- South Africa -- Eastern Cape -- Algoa bay Mytilus galloprovincialis -- South Africa -- Eastern Cape -- Algoa bay Mytilidae -- South Africa -- Eastern Cape -- Algoa bay
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5663 , http://hdl.handle.net/10962/d1005347
- Description: Recruitment of planktonic larvae into sedentary benthic populations regulates the population dynamics of marine invertebrates. The processes controlling recruitment, however, are poorly understood, and recruitment remains largely unpredictable, which complicates management of exploited shellfish resources. The mussels Perna perna, Choromytilus meridionalis and Mytilus galloprovincialis, found on the south coast of southern Africa, have planktonic larvae and sedentary adult stages. This thesis examines dispersal, settlement and early post-settlement growth and mortality, and their effect on recruitment and demography of intertidal mussel populations in the region of Algoa Bay on the south coast of southern Africa. Temporal and spatial variation in the body mass, density and size structure of mussels, the distribution of bivalve larvae on plankton grids in the nearshore zone and the distribution of a recently introduced invasive mussel, Mytilus galloprovincialis, were examined between 1989 and 1992. Furthermore, data on hourly or daily changes in wind strength and direction, air and sea surface temperatures and low and high tide levels in the study region, were obtained. There were 3-4 peaks in spawning (characterised by an abrupt decline in weight) and settlement activity annually. These peaks varied in exact timing, intensity and duration between sites and over time. However, at a site, spawning was followed by settlement 4-8 weeks later, and there was a significant (P < 0.05) direct correlation between spawning intensity prior to the appearance of a new cohort and the cohort density (settlement intensity). The stochastic spatial and temporal variation in breeding activity was superimposed on a more general pattern of a higher intensity of spawning and settlement in Algoa Bay than on the open coast, and a higher settlement intensity on coastal sandstone shores than on dune rock shores. Spawning was more frequent in winter and spring, and the probability of spawning and settlement peaked around the spring and autumn equinox, if temperature and wind conditions were suitable. Larval behaviour had little effect on their dispersal in the well-mixed nearshore region. Larvae were passively dispersed by currents, and their dispersal range and direction depended on prevailing winds and local topography. The sharp decline in density of recruit and adult M. galloprovincialis with increasing distance from the point of introduction, showed that some larvae were carried by wind generated currents over moderately long distances (-100 km). However, since most (76 %) M. galloprovincialis recruited within 4 km of the parent population, it is possible that larvae become trapped in small gullies and crevices around rocky shores, and have a limited dispersal range. This could explain the link between local patterns of spawning and settlement. The distribution and abundance of settlers on the shore was influenced by larval behaviour and the availability of settlement, substrata. Larvae preferred to settle primarily on foliose coralline algae and migrate to the adult mussel bed when they were larger (0.60-7 mm), but larvae also settled directly on adult mussels, possibly because the amount of coralline algae was limited. Both direct and secondary settlement were considered to be important in maintaining mussel populations since the rate of settlement was low(generally < 60 000.m-2). Cohort analyses showed that prior to maturity post-settlement growth (- 30 mm in 10 months) and mortality rates (60-100%) were high, but varied. When settlement intensity was low this variability uncoupled the relationship between spawning and recruitment intensity. Multiple regression analysis showed that together reproductive effort (gamete output), settlement intensity, growth and mortality prior to maturity, accounted for 76 % of the variance in recruitment into mature adult populations. The low settlement rate coupled with the short life span of mussels « 3 years), meant that populations underwent marked spatial and temporal variations in structure and abundance as settlement intensity varied, but there were consistent general differences between mussel populations on dune rock and sandstone shores in Algoa Bay and on the open coast. It was concluded from these results that, spawning intensity and post-settlement growth and mortality, rather than dispersal, regulated recruitment and the structure and abundance of intertidal P. perna and C. meridionalis populations along the south coast of southern Africa. On the basis of these results it is recommended that species with limited dispersal, variable recruitment and high natural mortality, such as P. perna, should be conserved by protecting a small part of the population in reserves, and controlling utilisation outside reserves to minimize disturbance to local brood stocks. Furthermore, since the potential for reseeding adjacent exploited areas is limited, several small reserves placed at regular intervals along the coast would be more effective than a single large reserve.
- Full Text:
- Date Issued: 1995
Disturbing the neighbours: an investigation into the relationship between psychopathology and social formations
- Authors: Collins, Anthony
- Date: 1995
- Subjects: Freud, Sigmund, 1856-1939 , Winnicott, D. W. (Donald Woods), 1896-1971 , Social psychiatry , Social psychology , Psychology, Pathological , Frankfurt school of sociology , Political psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2953 , http://hdl.handle.net/10962/d1002462 , Freud, Sigmund, 1856-1939 , Winnicott, D. W. (Donald Woods), 1896-1971 , Social psychiatry , Social psychology , Psychology, Pathological , Frankfurt school of sociology , Political psychology
- Description: This work attempts to confront certain political problems created by the individualistic bias in psychoanalytic thinking, and the resulting failure to adequately theorise the importance of social processes. The thesis traces the origins of intrapsychic thinking to Freud's initial move from the seduction theory to the Oedipal theory. This development is offered as a prototype for the debates between conceptualisations of childhood traumatisation as a social problem of actual abuse occurring within dermed power relations, and theories which locate pathology purely within internal conflicts occurring inside the individual. Several criticisms of this shift are offered, and it s impact on later theory is considered. Here a contrast is offered between the theoretical approaches of Melanie Klein and Donald Winnicott, arguing for the usefulness of Winnicott's emphasis on environmental factors within psychodynamic theory. The impact of these theoretical approaches is illustrated through a critical evaluation of Freud's case study of Judge Schreber. Additional historical material is brought in to show the importance of environmental considerations ignored by Freud, and contrasting psychodynamic readings of the case are offered. As an alternative to purely intrapsychic approaches, a reinterpretation of certain strands of Critical Theory is then presented. Adorno's theory of the Authoritarian Personality and Marcuse' s concept of One-Dimensional Man are extended using Winnicott's formulations concerning psychological development. This leads to an examination of the question of the relationship between social structure and individual consciousness. Post-structuralist accounts of language and the construction of identity are explored. These are then developed drawing on theories of ideology, language and consciousness, integrating these with Winnicott's developmental theory to offer an alternative psychodynamic understanding of the relationship between social process and psychopathology. An attempt is made to reformulate - the notions of consciousness and the unconscious in terms of the possibilities and difficulties of representation within available social symbolic codes. In conclusion the it is argued that psychology needs to integrate critical social theory and contemporary understandings of the social construction of consciousness in order to become a meaning force in positive social transformation.
- Full Text:
- Date Issued: 1995
- Authors: Collins, Anthony
- Date: 1995
- Subjects: Freud, Sigmund, 1856-1939 , Winnicott, D. W. (Donald Woods), 1896-1971 , Social psychiatry , Social psychology , Psychology, Pathological , Frankfurt school of sociology , Political psychology
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2953 , http://hdl.handle.net/10962/d1002462 , Freud, Sigmund, 1856-1939 , Winnicott, D. W. (Donald Woods), 1896-1971 , Social psychiatry , Social psychology , Psychology, Pathological , Frankfurt school of sociology , Political psychology
- Description: This work attempts to confront certain political problems created by the individualistic bias in psychoanalytic thinking, and the resulting failure to adequately theorise the importance of social processes. The thesis traces the origins of intrapsychic thinking to Freud's initial move from the seduction theory to the Oedipal theory. This development is offered as a prototype for the debates between conceptualisations of childhood traumatisation as a social problem of actual abuse occurring within dermed power relations, and theories which locate pathology purely within internal conflicts occurring inside the individual. Several criticisms of this shift are offered, and it s impact on later theory is considered. Here a contrast is offered between the theoretical approaches of Melanie Klein and Donald Winnicott, arguing for the usefulness of Winnicott's emphasis on environmental factors within psychodynamic theory. The impact of these theoretical approaches is illustrated through a critical evaluation of Freud's case study of Judge Schreber. Additional historical material is brought in to show the importance of environmental considerations ignored by Freud, and contrasting psychodynamic readings of the case are offered. As an alternative to purely intrapsychic approaches, a reinterpretation of certain strands of Critical Theory is then presented. Adorno's theory of the Authoritarian Personality and Marcuse' s concept of One-Dimensional Man are extended using Winnicott's formulations concerning psychological development. This leads to an examination of the question of the relationship between social structure and individual consciousness. Post-structuralist accounts of language and the construction of identity are explored. These are then developed drawing on theories of ideology, language and consciousness, integrating these with Winnicott's developmental theory to offer an alternative psychodynamic understanding of the relationship between social process and psychopathology. An attempt is made to reformulate - the notions of consciousness and the unconscious in terms of the possibilities and difficulties of representation within available social symbolic codes. In conclusion the it is argued that psychology needs to integrate critical social theory and contemporary understandings of the social construction of consciousness in order to become a meaning force in positive social transformation.
- Full Text:
- Date Issued: 1995
Editorial
- Authors: Janse van Rensburg, Eureta
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438706 , vital:73493 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137460"
- Description: This edition of the SAJEE focuses on EEASA' s conference-and-workshops held in July 1995, at Kearsney College in Kwazulu Natal, South Africa. ln the 1994 issue we invited readers to explore Progress and Paradox, as a conference theme reflecting a new perspective on education and environment. We received a very positive response and the conference featured an excellent range of papers. From amongst the many worthy contributions the reviewers selected those papers that addressed the theme most directly, for publication in this, arguably EEASA' s best journal yet.
- Full Text:
- Date Issued: 1995
- Authors: Janse van Rensburg, Eureta
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438706 , vital:73493 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137460"
- Description: This edition of the SAJEE focuses on EEASA' s conference-and-workshops held in July 1995, at Kearsney College in Kwazulu Natal, South Africa. ln the 1994 issue we invited readers to explore Progress and Paradox, as a conference theme reflecting a new perspective on education and environment. We received a very positive response and the conference featured an excellent range of papers. From amongst the many worthy contributions the reviewers selected those papers that addressed the theme most directly, for publication in this, arguably EEASA' s best journal yet.
- Full Text:
- Date Issued: 1995
Environmental education and research in southern Africa: a landscape of shifting priorities
- Authors: Van Rensburg, Eureta Janse
- Date: 1995
- Subjects: Environmental education -- Research -- South Africa Environmental sciences -- Study and teaching (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1513 , http://hdl.handle.net/10962/d1003395
- Description: What has come to be labelled as 'the environment crisis' has roots in the structures and orientations of modern societies. True to our modernist ways we call on, or offer, education and research, experts and science, to address our socio-ecological concerns. This study set out to identify research priorities in environmental education from within the institutional setting of a university and within the context of environmental and political change in southern Africa and epistemological shifts in educational research traditions. The emergent research design allowed for a progressive clarification of theoretical vantage point: from an instrumental listing of priorities, through the participatory development of a critical and consensual framework for research, to a reflexive description of a landscape of shifting priorities. I collected data over a 3-year period, in inter alia 38 semi-structured interviews, workshops with some 150 participants, focus group discussions, documents and conferences. Participants' professional contexts included environmental education, natural resource management, social and biophysical sciences, development, formal and non-formal education, funding agencies, academic and non-academic settings. My engagement with the emerging discourses revealed patterns and inconsistencies in participants' views on research, environmental education, change and research priorities. I identified three orientations - Research for Management to Restore Order to Nature and Society, Research to Resolve Practitioners' and Communities' Problems, and Research for Radical Reconstruction - in the emerging landscape. These orientations were accompanied by change models and themes (discourses of difference and 'othering', instrumental views of education and research and accumulative knowledge, a conceptual theory-practice gap) which limited their potential for transformation towards sustainable living. They presented solutions cut from the same modernist cloth as the environment crisis. An emerging Reflexive perspective in and on environmental education research showed potential as a transitionary orientation outside modernist assumptions. I outline research priorities from this perspective. Reflexivity reveals the myths of expert-driven, instrumental and institutionalised research separated from environmental education and based upon rationalistic interpretations of science. It opens up possibilities for transformative knowledge emerging from 're-search' based versions of education as a process of, rather than a means to, social change.
- Full Text:
- Date Issued: 1995
- Authors: Van Rensburg, Eureta Janse
- Date: 1995
- Subjects: Environmental education -- Research -- South Africa Environmental sciences -- Study and teaching (Higher) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1513 , http://hdl.handle.net/10962/d1003395
- Description: What has come to be labelled as 'the environment crisis' has roots in the structures and orientations of modern societies. True to our modernist ways we call on, or offer, education and research, experts and science, to address our socio-ecological concerns. This study set out to identify research priorities in environmental education from within the institutional setting of a university and within the context of environmental and political change in southern Africa and epistemological shifts in educational research traditions. The emergent research design allowed for a progressive clarification of theoretical vantage point: from an instrumental listing of priorities, through the participatory development of a critical and consensual framework for research, to a reflexive description of a landscape of shifting priorities. I collected data over a 3-year period, in inter alia 38 semi-structured interviews, workshops with some 150 participants, focus group discussions, documents and conferences. Participants' professional contexts included environmental education, natural resource management, social and biophysical sciences, development, formal and non-formal education, funding agencies, academic and non-academic settings. My engagement with the emerging discourses revealed patterns and inconsistencies in participants' views on research, environmental education, change and research priorities. I identified three orientations - Research for Management to Restore Order to Nature and Society, Research to Resolve Practitioners' and Communities' Problems, and Research for Radical Reconstruction - in the emerging landscape. These orientations were accompanied by change models and themes (discourses of difference and 'othering', instrumental views of education and research and accumulative knowledge, a conceptual theory-practice gap) which limited their potential for transformation towards sustainable living. They presented solutions cut from the same modernist cloth as the environment crisis. An emerging Reflexive perspective in and on environmental education research showed potential as a transitionary orientation outside modernist assumptions. I outline research priorities from this perspective. Reflexivity reveals the myths of expert-driven, instrumental and institutionalised research separated from environmental education and based upon rationalistic interpretations of science. It opens up possibilities for transformative knowledge emerging from 're-search' based versions of education as a process of, rather than a means to, social change.
- Full Text:
- Date Issued: 1995
Equal opportunities for women
- Federation of Unions of South Africa
- Authors: Federation of Unions of South Africa
- Date: 1995
- Subjects: FEDUSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110109 , vital:33224
- Description: Over the last thirty years, there has been considerable evolution in the thinking about gender equality issues and the actions needed to achieve real changes in the position of women vis-a-vis men. Prior to the 1970s, women were defined mainly in terms of their conventional reproductive roles, and efforts to improve women's welfare focussed on such programmes as literacy courses, home economics, child care and family planning. Though no doubt valuable, such welfare and family-oriented programmes had the effect of reinforcing women's traditional role in the family. Since the 1970s, there has been a shift to the division of labour based on sex, and the impact of development and modernization strategies on women. It is important to understand that improvements in women's status require analysis of the relations between men and women, as well as the concurrence and cooperation of men. As illustrated in the Beijing document: "Achieving gender equality and empowerment of women requires redressing inequalities between women and men and girls and boys and ensuring their equal rights, responsibilities, opportunities and possibilities. Gender equality implies that women's as well as men's needs, interests, concerns, experiences and priorities are an integral dimension of the design, implementation, national monitoring and follow-up and evaluation, including at the international level, of all actions in all areas."
- Full Text:
- Date Issued: 1995
- Authors: Federation of Unions of South Africa
- Date: 1995
- Subjects: FEDUSA
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/110109 , vital:33224
- Description: Over the last thirty years, there has been considerable evolution in the thinking about gender equality issues and the actions needed to achieve real changes in the position of women vis-a-vis men. Prior to the 1970s, women were defined mainly in terms of their conventional reproductive roles, and efforts to improve women's welfare focussed on such programmes as literacy courses, home economics, child care and family planning. Though no doubt valuable, such welfare and family-oriented programmes had the effect of reinforcing women's traditional role in the family. Since the 1970s, there has been a shift to the division of labour based on sex, and the impact of development and modernization strategies on women. It is important to understand that improvements in women's status require analysis of the relations between men and women, as well as the concurrence and cooperation of men. As illustrated in the Beijing document: "Achieving gender equality and empowerment of women requires redressing inequalities between women and men and girls and boys and ensuring their equal rights, responsibilities, opportunities and possibilities. Gender equality implies that women's as well as men's needs, interests, concerns, experiences and priorities are an integral dimension of the design, implementation, national monitoring and follow-up and evaluation, including at the international level, of all actions in all areas."
- Full Text:
- Date Issued: 1995
Equilibrium and kinetic studies of the reaction between pyridine and cobalt (II) phthalocyanine in DMSO
- Authors: Nyokong, Tebello
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293380 , vital:57080 , xlink:href="https://doi.org/10.1016/0277-5387(95)00090-F"
- Description: Kinetics and equilibria for the reaction between pyridine and cobalt(II) phthalocyanine [CoPc] (H2Pc = phthalocyanine) in dimethyl sulphoxide (DMSO) were studied at 25°C. The complex, CoPc(py)2, is formed in two consecutive steps. The formation of the mono-substituted CoPc(py)(DMSO) occurs first with a pseudo-first-order rate constant of k1f = 7.7 ± 0.3 × 10−3 dm3 mol−1 s−1. The final disubstituted CoPc(py)2 complex is formed with k2f= 1.1 ± 0.1 × 10−4dm3mol−1−1. The equilibrium constants were found to be K1 = 160 ± 20dm3 mol−1 and K2 = 15 ± 3 dm3mol−1 for the formation of CoPc(py)(DMSO) and CoPc(py)2, respectively.
- Full Text:
- Date Issued: 1995
- Authors: Nyokong, Tebello
- Date: 1995
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/293380 , vital:57080 , xlink:href="https://doi.org/10.1016/0277-5387(95)00090-F"
- Description: Kinetics and equilibria for the reaction between pyridine and cobalt(II) phthalocyanine [CoPc] (H2Pc = phthalocyanine) in dimethyl sulphoxide (DMSO) were studied at 25°C. The complex, CoPc(py)2, is formed in two consecutive steps. The formation of the mono-substituted CoPc(py)(DMSO) occurs first with a pseudo-first-order rate constant of k1f = 7.7 ± 0.3 × 10−3 dm3 mol−1 s−1. The final disubstituted CoPc(py)2 complex is formed with k2f= 1.1 ± 0.1 × 10−4dm3mol−1−1. The equilibrium constants were found to be K1 = 160 ± 20dm3 mol−1 and K2 = 15 ± 3 dm3mol−1 for the formation of CoPc(py)(DMSO) and CoPc(py)2, respectively.
- Full Text:
- Date Issued: 1995