An application of the natural area concept to East London apartment areas
- Authors: Brehmer, D A E
- Date: 1975
- Subjects: Natural areas -- South Africa -- East London , Apartment houses -- South Africa -- East London , Urban ecology (Sociology) -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4872 , http://hdl.handle.net/10962/d1009694 , Natural areas -- South Africa -- East London , Apartment houses -- South Africa -- East London , Urban ecology (Sociology) -- South Africa -- East London
- Description: The world is faced with a population explosion, and cities are becoming ever larger. The world population will grow from its present 3500 million to more than 7 000 million by the year 2 000. The majority of cities are thus faced with the problem of housing vast numbers of people living in single family dwellings forming low density urban sprawl. Conditions are no different in South Africa where the present white population of about four million is expected to grow to between six and seven million by the year 2000. The present housing requirement (1970-75) for Whites, based on low and high population projections, is 32 732 and 40 150 houses respectively. From 1995-2000 the figures will have risen to 42 742 and 65 580 respectively. At that rate sprawl here will reach alarming proportions unless it can be curtailed by higher density housing. As the population trend does not seem likely to be reversed the problem lies in how to provide housing for an escalating population but at the same time to reduce urban sprawl and provide satisfactory living conditions.
- Full Text:
- Date Issued: 1975
- Authors: Brehmer, D A E
- Date: 1975
- Subjects: Natural areas -- South Africa -- East London , Apartment houses -- South Africa -- East London , Urban ecology (Sociology) -- South Africa -- East London
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4872 , http://hdl.handle.net/10962/d1009694 , Natural areas -- South Africa -- East London , Apartment houses -- South Africa -- East London , Urban ecology (Sociology) -- South Africa -- East London
- Description: The world is faced with a population explosion, and cities are becoming ever larger. The world population will grow from its present 3500 million to more than 7 000 million by the year 2 000. The majority of cities are thus faced with the problem of housing vast numbers of people living in single family dwellings forming low density urban sprawl. Conditions are no different in South Africa where the present white population of about four million is expected to grow to between six and seven million by the year 2000. The present housing requirement (1970-75) for Whites, based on low and high population projections, is 32 732 and 40 150 houses respectively. From 1995-2000 the figures will have risen to 42 742 and 65 580 respectively. At that rate sprawl here will reach alarming proportions unless it can be curtailed by higher density housing. As the population trend does not seem likely to be reversed the problem lies in how to provide housing for an escalating population but at the same time to reduce urban sprawl and provide satisfactory living conditions.
- Full Text:
- Date Issued: 1975
Remarks on formalized arithmetic and subsystems thereof
- Brink, C
- Authors: Brink, C
- Date: 1975
- Subjects: Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5424 , http://hdl.handle.net/10962/d1009752 , Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Description: In a famous paper of 1931, Gödel proved that any formalization of elementary Arithmetic is incomplete, in the sense that it contains statements which are neither provable nor disprovable. Some two years before this, Presburger proved that a mutilated system of Arithmetic, employing only addition but not multiplication, is complete. This essay is partly an exposition of a system such as Presburger's, and partly an attempt to gain insight into the source of the incompleteness of Arithmetic, by linking Presburger's result with Gödel's.
- Full Text:
- Date Issued: 1975
- Authors: Brink, C
- Date: 1975
- Subjects: Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5424 , http://hdl.handle.net/10962/d1009752 , Gödel, Kurt , Logic, Symbolic and mathematical , Semantics (Philosophy) , Arithmetic -- Foundations , Number theory
- Description: In a famous paper of 1931, Gödel proved that any formalization of elementary Arithmetic is incomplete, in the sense that it contains statements which are neither provable nor disprovable. Some two years before this, Presburger proved that a mutilated system of Arithmetic, employing only addition but not multiplication, is complete. This essay is partly an exposition of a system such as Presburger's, and partly an attempt to gain insight into the source of the incompleteness of Arithmetic, by linking Presburger's result with Gödel's.
- Full Text:
- Date Issued: 1975
A new Barbus species (Pisces, Cyprinidae) from the Olifants River System, Western Cape Province, South Africa
- Skelton, Paul H (Paul Harvey), Rhodes University. J.L.B. Smith Institute of Ichthyology
- Authors: Skelton, Paul H (Paul Harvey) , Rhodes University. J.L.B. Smith Institute of Ichthyology
- Date: 1974-08
- Subjects: Barbus erubescens , Freshwater fishes -- South Africa -- Olifants River (Clanwilliam District, Cape of Good Hope)
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69715 , vital:29570 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 13 , A new species of small Barbus is described from the Olifants River System, western Cape Province, South Africa. The new species is restricted to a single tributary complex of the river system and appears closely related to B. calidus. Diagnostic features include pharyngeal teeth formulae, colour pattern, and dorsal and anal fin ray characteristics.
- Full Text:
- Date Issued: 1974-08
- Authors: Skelton, Paul H (Paul Harvey) , Rhodes University. J.L.B. Smith Institute of Ichthyology
- Date: 1974-08
- Subjects: Barbus erubescens , Freshwater fishes -- South Africa -- Olifants River (Clanwilliam District, Cape of Good Hope)
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69715 , vital:29570 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 13 , A new species of small Barbus is described from the Olifants River System, western Cape Province, South Africa. The new species is restricted to a single tributary complex of the river system and appears closely related to B. calidus. Diagnostic features include pharyngeal teeth formulae, colour pattern, and dorsal and anal fin ray characteristics.
- Full Text:
- Date Issued: 1974-08
Rediscovery of certain type specimens of fishes from the collections of the Government Marine Survey made by J.D.F. Gilchrist & the S.S. Pickle
- Winterbottom, Richard, 1944-, Gilchrist, J D F (John Dow Fisher), 1866-1926, Rhodes University. J.L.B. Smith Institute of Ichthyology
- Authors: Winterbottom, Richard, 1944- , Gilchrist, J D F (John Dow Fisher), 1866-1926 , Rhodes University. J.L.B. Smith Institute of Ichthyology
- Date: 1974-05
- Subjects: Fishes -- Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69684 , vital:29565 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 12 , The discovery in the J.L.B. Smith Institute of Ichthyology of type material of 14 species of fishes from the collections made by the S.S. ‘Pickle’ (1920-1924) off the South African coast is reported. Brief redescriptions of, and new catalogue numbers for, the specimens are given.
- Full Text:
- Date Issued: 1974-05
- Authors: Winterbottom, Richard, 1944- , Gilchrist, J D F (John Dow Fisher), 1866-1926 , Rhodes University. J.L.B. Smith Institute of Ichthyology
- Date: 1974-05
- Subjects: Fishes -- Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/69684 , vital:29565 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 12 , The discovery in the J.L.B. Smith Institute of Ichthyology of type material of 14 species of fishes from the collections made by the S.S. ‘Pickle’ (1920-1924) off the South African coast is reported. Brief redescriptions of, and new catalogue numbers for, the specimens are given.
- Full Text:
- Date Issued: 1974-05
"Complexes of carbohydrates with magnesium-ions" : "the isolation of an oligosaccharide containing L-galactose from the polysaccharide of Aeodes orbitosa" : "horizontal cellulose colum chromatography of sugars"
- Authors: Van der Linde, Michael John
- Date: 1974
- Subjects: Magenesium , Ions , Carbohydrates , Oligosaccharides , Polysaccharides , Chromatographic analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4504 , http://hdl.handle.net/10962/d1013282
- Description: Sugar complexes with anions and cations are reviewed. Evidence is presented for the formation of a complex of stoichiometry 1:1 in aqueous solution between methyl-α-Dglucopyranoside and magnesium perchlorate. The complex may be detected by the method of continuous variations. Measurements of changes in the proton chemical shifts of the glucoside in dauterium oxide, indicate that the complex is probably formed between the vicinal hydroxyl groups at C-2 and C-3 of the pyranoside ring and the hydrated cation. At elevation temperatures there is evidence for the presence of a complex of stoichiometry 2:1. Experiments conducted on cellulose indicate the possible formation of cellulose - magnesium-ion complexes . These complexes provide an explanation for the "protective action" of mEgnesium compounds on the cellulose portion of pulp during alkali-oxygen bleaching.
- Full Text:
- Date Issued: 1974
- Authors: Van der Linde, Michael John
- Date: 1974
- Subjects: Magenesium , Ions , Carbohydrates , Oligosaccharides , Polysaccharides , Chromatographic analysis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4504 , http://hdl.handle.net/10962/d1013282
- Description: Sugar complexes with anions and cations are reviewed. Evidence is presented for the formation of a complex of stoichiometry 1:1 in aqueous solution between methyl-α-Dglucopyranoside and magnesium perchlorate. The complex may be detected by the method of continuous variations. Measurements of changes in the proton chemical shifts of the glucoside in dauterium oxide, indicate that the complex is probably formed between the vicinal hydroxyl groups at C-2 and C-3 of the pyranoside ring and the hydrated cation. At elevation temperatures there is evidence for the presence of a complex of stoichiometry 2:1. Experiments conducted on cellulose indicate the possible formation of cellulose - magnesium-ion complexes . These complexes provide an explanation for the "protective action" of mEgnesium compounds on the cellulose portion of pulp during alkali-oxygen bleaching.
- Full Text:
- Date Issued: 1974
"Holy baptism" : a reconsideration of the doctrine of holy baptism in the light of recent research
- Authors: Moore, Robert Humphrey
- Date: 1974
- Subjects: Baptism in the Holy Spirit , Holy Spirit -- Biblical teaching
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1239 , http://hdl.handle.net/10962/d1007686 , Baptism in the Holy Spirit , Holy Spirit -- Biblical teaching
- Description: Conclusion: This study has helped us to perceive the significance of Christian Baptism as it arose from its antecedents, and yet differed decisively from them in meaning and significance. We have seen how Baptism grew from the New Testament situation into the life of the Early Church. We have considered the sacramental nature of Baptism, that here, while the Community is visibly active, in this holy sacrament, God is the doer of what is done. It is by Him, whose Grace is seen in Jesus Christ, that we are brought to new life within the Community of His Covenant and what He can do for adults, He can do for infants as well. However, it is good for us to remember that His presence is also for our judgement, and that there therefore remains upon us as individuals and as Community the requirement of faith and faithfulness. We have seen how it is that the Holy Spirit is given in Baptism, and we believe it is through His indwelling presence and power that we are able to come into the Family of God and enjoy that fellowship with Him, which is salvation. We have also seen that, despite many centuries of thought and study, no final doctrinal definition of Baptism is yet achieved, and that the Churches are still giving this serious attention.
- Full Text:
- Date Issued: 1974
- Authors: Moore, Robert Humphrey
- Date: 1974
- Subjects: Baptism in the Holy Spirit , Holy Spirit -- Biblical teaching
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1239 , http://hdl.handle.net/10962/d1007686 , Baptism in the Holy Spirit , Holy Spirit -- Biblical teaching
- Description: Conclusion: This study has helped us to perceive the significance of Christian Baptism as it arose from its antecedents, and yet differed decisively from them in meaning and significance. We have seen how Baptism grew from the New Testament situation into the life of the Early Church. We have considered the sacramental nature of Baptism, that here, while the Community is visibly active, in this holy sacrament, God is the doer of what is done. It is by Him, whose Grace is seen in Jesus Christ, that we are brought to new life within the Community of His Covenant and what He can do for adults, He can do for infants as well. However, it is good for us to remember that His presence is also for our judgement, and that there therefore remains upon us as individuals and as Community the requirement of faith and faithfulness. We have seen how it is that the Holy Spirit is given in Baptism, and we believe it is through His indwelling presence and power that we are able to come into the Family of God and enjoy that fellowship with Him, which is salvation. We have also seen that, despite many centuries of thought and study, no final doctrinal definition of Baptism is yet achieved, and that the Churches are still giving this serious attention.
- Full Text:
- Date Issued: 1974
'n Ondersoek na Afrikaanse beskouings oor die kortverhaal met besondere verwysing na enkele nuwer Afrikaanse verhale
- Authors: Du Toit, P A
- Date: 1974
- Subjects: Short stories, South African (Afrikaans) -- History and criticism
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3628 , http://hdl.handle.net/10962/d1011504 , Short stories, South African (Afrikaans) -- History and criticism
- Description: Dit is reeds deur andere gese: dat die "vernuwing van Sestig" in die Afrikaanse prosa die Afrikaanse prosakritiek tot bestekname gedwing het soos die vernuwing in die poësie van Dertig die kritiek van daardie tyd. En waar die vernuwing in die prosa ook op die gebied van die kort prosakuns so duidelik op die voorgrond was, kan daar wel gevra word: hoe geldig is die teorieDit is reeds deur andere gess: dat die "vernuwing van Sestig" in die Afrikaanse prosa die Afrikaanse prosakritiek tot bestekname gedwing het soos die vernuwing in die poesie van Dertig die kritiek van daardie tyd. 2 En waar die vernuwing in die prosa ook op die gebied van die kort prosakuns so duidelik op die voorgrond was, kan daar wel gevra word: hoe geldig is die teorieë wat in Afrikaans so eksplisit oor die "kortverhaal" opgestel is vir die nuwer Afrikaanse verhaalkuns? en daarby: hoe geldig is die nuwer, meer teksgerigte beskouings in Afrikaans? Die vraag is die kern van die huidige studie.
- Full Text:
- Date Issued: 1974
- Authors: Du Toit, P A
- Date: 1974
- Subjects: Short stories, South African (Afrikaans) -- History and criticism
- Language: Afrikaans
- Type: Thesis , Masters , MA
- Identifier: vital:3628 , http://hdl.handle.net/10962/d1011504 , Short stories, South African (Afrikaans) -- History and criticism
- Description: Dit is reeds deur andere gese: dat die "vernuwing van Sestig" in die Afrikaanse prosa die Afrikaanse prosakritiek tot bestekname gedwing het soos die vernuwing in die poësie van Dertig die kritiek van daardie tyd. En waar die vernuwing in die prosa ook op die gebied van die kort prosakuns so duidelik op die voorgrond was, kan daar wel gevra word: hoe geldig is die teorieDit is reeds deur andere gess: dat die "vernuwing van Sestig" in die Afrikaanse prosa die Afrikaanse prosakritiek tot bestekname gedwing het soos die vernuwing in die poesie van Dertig die kritiek van daardie tyd. 2 En waar die vernuwing in die prosa ook op die gebied van die kort prosakuns so duidelik op die voorgrond was, kan daar wel gevra word: hoe geldig is die teorieë wat in Afrikaans so eksplisit oor die "kortverhaal" opgestel is vir die nuwer Afrikaanse verhaalkuns? en daarby: hoe geldig is die nuwer, meer teksgerigte beskouings in Afrikaans? Die vraag is die kern van die huidige studie.
- Full Text:
- Date Issued: 1974
A contribution to the biology of Pseudodiaptomus hessei (Mrázek) (Copepoda : Calanoida) in Lake Sibaya, South Africa
- Authors: Hart, Robert Clynton
- Date: 1974
- Subjects: Copepoda -- South Africa Freshwater biology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5854 , http://hdl.handle.net/10962/d1012210
- Description: Aspects of the biology of the calanoid copepod Pseudodiaptomus hessei are described, with particular reference to its vertical migratory behaviour. The present investigations were carried out largely by means of Nansen-type plankton nets, but several new pieces of apparatus were developed and. are described herein. The daytime vertical distribution of P. hessei varies according to developmental stage and depth of water. In shallow areas of the lake the entire population is benthic or in very close association with the lake bed. In the deepest part of the lake (40m) the naupliar and early (i.e. C I - C III) copepodite stages are essentially pelagic, but the adult and late (i.e. C IV - C V) copepodite stages are predominantly benthic and may be quiescent or infaunal. During the hours of darkness, the calanoids are distributed through the water column. The nauplii are consistently abundant in the surface waters but the distribution of the other stages is not regular. The distribution can be related to lunar intensity in many cases, with the post-naupliar stages frequently occurring deeper in the water column on bright moonlight nights and in the surface waters on overcast moolnless nights. The dusk ascent and dawn descent of the calenoids is clearly related to changes in light penetration in most individuals. The movements of a fraction of the adults occur in the apparent absence of adequate light cues. This behaviour is shown more extensively by the adult females. An endogenous activity rhythm has been shown in the species under laboratory conditions and it is suggested that this may play a part in the migratory movements. A basic examination of the feeding methods, feeding appendages and food sources of adult and late copepodite stages has been made. Changes in feeding intensity through twenty-four have been examined in the field and under laboratory conditions. Using as an index of feeding intensity, the proportion of animals with food in their guts, it has been shown that a pronounced diel difference occurs in adult calanoids in the lake. Feeding is almost entirely restricted to the nocturnal presence of the calanoids in the water coloumn. This difference exists in the pre-adult copepodite stages, but is not nearly as striking. The absence of feeding during daylight is not readily accounted for in terms of food availability and it is attributed to the quiescent or possible infaunal existence of the adults. A periodicity in egg hatching has been shown Naupliar release from the parental egg sac is predominantly a nocturnal phenomenon in the hot and cool seasons. It is suggested that this may be important in attaining a favourable vertical distritution for the nauplii, and may be important in the distribution of the species. A preliminary acccunt of the seasonal cycle and population dynamics of P. hessei is given, based on data collected over two years at a single station. Seasonal changes in calanoid abundance are intermediate between those recorded in truly tropical areas and in temperate latitudes. Potential food sources show relatively little change. The vertical migration of P. hessei is considered in relation to its apparent ecological significance and comparisons are drawn with observations made on the same species or other pseudodiaptomids in estuaries and lagoons elsewhere.
- Full Text:
- Date Issued: 1974
- Authors: Hart, Robert Clynton
- Date: 1974
- Subjects: Copepoda -- South Africa Freshwater biology -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5854 , http://hdl.handle.net/10962/d1012210
- Description: Aspects of the biology of the calanoid copepod Pseudodiaptomus hessei are described, with particular reference to its vertical migratory behaviour. The present investigations were carried out largely by means of Nansen-type plankton nets, but several new pieces of apparatus were developed and. are described herein. The daytime vertical distribution of P. hessei varies according to developmental stage and depth of water. In shallow areas of the lake the entire population is benthic or in very close association with the lake bed. In the deepest part of the lake (40m) the naupliar and early (i.e. C I - C III) copepodite stages are essentially pelagic, but the adult and late (i.e. C IV - C V) copepodite stages are predominantly benthic and may be quiescent or infaunal. During the hours of darkness, the calanoids are distributed through the water column. The nauplii are consistently abundant in the surface waters but the distribution of the other stages is not regular. The distribution can be related to lunar intensity in many cases, with the post-naupliar stages frequently occurring deeper in the water column on bright moonlight nights and in the surface waters on overcast moolnless nights. The dusk ascent and dawn descent of the calenoids is clearly related to changes in light penetration in most individuals. The movements of a fraction of the adults occur in the apparent absence of adequate light cues. This behaviour is shown more extensively by the adult females. An endogenous activity rhythm has been shown in the species under laboratory conditions and it is suggested that this may play a part in the migratory movements. A basic examination of the feeding methods, feeding appendages and food sources of adult and late copepodite stages has been made. Changes in feeding intensity through twenty-four have been examined in the field and under laboratory conditions. Using as an index of feeding intensity, the proportion of animals with food in their guts, it has been shown that a pronounced diel difference occurs in adult calanoids in the lake. Feeding is almost entirely restricted to the nocturnal presence of the calanoids in the water coloumn. This difference exists in the pre-adult copepodite stages, but is not nearly as striking. The absence of feeding during daylight is not readily accounted for in terms of food availability and it is attributed to the quiescent or possible infaunal existence of the adults. A periodicity in egg hatching has been shown Naupliar release from the parental egg sac is predominantly a nocturnal phenomenon in the hot and cool seasons. It is suggested that this may be important in attaining a favourable vertical distritution for the nauplii, and may be important in the distribution of the species. A preliminary acccunt of the seasonal cycle and population dynamics of P. hessei is given, based on data collected over two years at a single station. Seasonal changes in calanoid abundance are intermediate between those recorded in truly tropical areas and in temperate latitudes. Potential food sources show relatively little change. The vertical migration of P. hessei is considered in relation to its apparent ecological significance and comparisons are drawn with observations made on the same species or other pseudodiaptomids in estuaries and lagoons elsewhere.
- Full Text:
- Date Issued: 1974
A contribution to the limnology of Swartvlei: the effect of physico-chemical factors upon primary and secondary production in the pelagic zone
- Authors: Robarts, R D (Richard D)
- Date: 1974
- Subjects: Limnology -- South Africa -- Swartvlei
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5822 , http://hdl.handle.net/10962/d1007474
- Description: From Resumé: The effect of physico-chemical factors on the biology of the upper reaches of Swartvlei has been investigated during 1971-1972. Physico-chemical data have shown that Swartvlei was characterized by an extremely labile ectogenic meromixis. This instability was due to three factors : (1) the inflow of freshwater, (2) the inflow of sea water, and (3) wind stress. The magnitude of the effects of these factors upon the physics, chemistry and biology of the upper reaches was dependent upon whether or not the estuary mouth was open or closed. The phytoplankton of the pelagic zone of Swartvlei was dominated by nannoplankton. Three major categories were recorded: dinoflagellates, flagellates and diatoms. The major factor regulating their productivity in the upper reaches was light. As a result of humate staining and suspended detrital matter light conditions in Swartvlei were comparable to those in extremely eutrophic northern hemisphere lakes. A maximum integral primary productivity of 39.66 mg C m⁻² h⁻¹ was recorded in November 1972. The aerobic heterotrophic bacterial population in Swartvlei was usually less than 300 col. ml⁻¹ (plate counts). The activity of the total microbial population was measured with ¹⁴C techniques. Uptake of acetate was dominated by flagellates and one species of dinoflagellate when they were present. Glucose uptake was due to bacteria as was acetate uptake in the absence of heterotrophic phytoplankton. Glucose uptake was usually greatest in the anaerobic zone. This, and the presence of H₂S, suggested that a large active photosynthetic and chemosynthetic bacterial population may have been present in the monimolimnion. The possible importance of these bacterial processes in the total productivity of the pelagic zone of Swartvlei was discussed. Daytime zooplankton population size was statistically correlated with the size of the flagellate population. The zooplankton was dominated by Acartia and Halicyclops. These two animals were found in the anaerobic bottom of Swartvlei after October 1971. This corresponded to the disappearance of the flagellate population from the water column. The dominance of these animals in the zooplankton population may have been related to their ability to live in anaerobic water where the bacterial population appeared to be considerably more abundant than in the aerobic zone. Further implications of the results are discussed in reference to phytoplankton cell size and heterotrophy indicating a possible adaptive significance of these factors in Swartvlei.
- Full Text:
- Date Issued: 1974
- Authors: Robarts, R D (Richard D)
- Date: 1974
- Subjects: Limnology -- South Africa -- Swartvlei
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5822 , http://hdl.handle.net/10962/d1007474
- Description: From Resumé: The effect of physico-chemical factors on the biology of the upper reaches of Swartvlei has been investigated during 1971-1972. Physico-chemical data have shown that Swartvlei was characterized by an extremely labile ectogenic meromixis. This instability was due to three factors : (1) the inflow of freshwater, (2) the inflow of sea water, and (3) wind stress. The magnitude of the effects of these factors upon the physics, chemistry and biology of the upper reaches was dependent upon whether or not the estuary mouth was open or closed. The phytoplankton of the pelagic zone of Swartvlei was dominated by nannoplankton. Three major categories were recorded: dinoflagellates, flagellates and diatoms. The major factor regulating their productivity in the upper reaches was light. As a result of humate staining and suspended detrital matter light conditions in Swartvlei were comparable to those in extremely eutrophic northern hemisphere lakes. A maximum integral primary productivity of 39.66 mg C m⁻² h⁻¹ was recorded in November 1972. The aerobic heterotrophic bacterial population in Swartvlei was usually less than 300 col. ml⁻¹ (plate counts). The activity of the total microbial population was measured with ¹⁴C techniques. Uptake of acetate was dominated by flagellates and one species of dinoflagellate when they were present. Glucose uptake was due to bacteria as was acetate uptake in the absence of heterotrophic phytoplankton. Glucose uptake was usually greatest in the anaerobic zone. This, and the presence of H₂S, suggested that a large active photosynthetic and chemosynthetic bacterial population may have been present in the monimolimnion. The possible importance of these bacterial processes in the total productivity of the pelagic zone of Swartvlei was discussed. Daytime zooplankton population size was statistically correlated with the size of the flagellate population. The zooplankton was dominated by Acartia and Halicyclops. These two animals were found in the anaerobic bottom of Swartvlei after October 1971. This corresponded to the disappearance of the flagellate population from the water column. The dominance of these animals in the zooplankton population may have been related to their ability to live in anaerobic water where the bacterial population appeared to be considerably more abundant than in the aerobic zone. Further implications of the results are discussed in reference to phytoplankton cell size and heterotrophy indicating a possible adaptive significance of these factors in Swartvlei.
- Full Text:
- Date Issued: 1974
A cross cultural study of eidetic imagery and short term memory
- Authors: Lewis, William Michael
- Date: 1974
- Subjects: Cross-cultural studies , Eidetic imagery , Short-term memory
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3141 , http://hdl.handle.net/10962/d1007182 , Cross-cultural studies , Eidetic imagery , Short-term memory
- Description: The complexity of behaviour necessitates a clear and concise approach in order to comprehend its functioning. An example of such an approach is highlighted by the field of cybernetics. Cybernetic models have been used extensively throughout the various fields of Psychology but perhaps never more so as in the case of short term memory (STM). This particular field abounds with behavioural models and research workers are constantly developing new models or testing the universality of existing models. Universal validity is essential to the strength of the behavioural principles inherent in any model but unfortunately such validity tends to be neglected. The present study attempts to reconcile this position with reference to specific models of STM, with relation to the phenomena of eidetic imagery (EI). Certain studies concerning the incidence of EI in illiterate Africans have produced results which are contradictory to those obtained in the Western culture. Two of the most important contradictions concern the fact that the illiterate Africans experienced the absence of an age parameter on the occurrence of such imagery and the fact that the incidence of imagery was more extensive in the African culture. A reason for these contradictions was sought and it was reasoned that as eidetic images have been closely linked with memory images, it may, therefore, be assumed that these particular cultures may use EI as an aid to memory in the absence of written material. Further, it would not be unreasonable to assume that this visual imagery may tend to dominate the STM process and thereby challenge the universality of those memory models that proposed acoustic domination of this process. No work has been done in investigating the memory process of the Africans. Thus, a study which did so would not only test the universality of specific memory models but would also possibly throw more light on the memory process itself. In this particular study there were three specific aims; (a) to ascertain the relative incidence of EI on a cross-cultural level, (b) to assess the influence of EI on the memory process, and (c) to ascertain the extent to which principles of STM developed in the West applied to the African groups. The groups concerned in the study comprised two Xhosa groups and a European group. The European group (WS) was drawn from a White Student population at Rhodes University and was regarded as a control group. The equivalent literate Xhosa group (BS) was drawn from a Black Student population at the University of Fort Hare. The illiterate Xhosa group (RX) was drawn from a population of Red Xhosa people in the Transkei. Four tasks were administered to the groups with the cross-cultural variable carefully controlled as much as possible. The following comprised the four tasks; (a) eidetic imagery (b) auditory serial recall (c) visual serial recall and (d) an acoustic confusable task. Each subject commenced with the eidetic imagery task and was then confronted with a random presentation of the other three tasks. The EI task began with an after image task which was foIlowed by three selected pictures which comprised the EI task. After each picture presentation the subject was closely questioned as to the presence of imagery. Scoring was of a subjective nature. The visual and acoustic confusion tasks constituted serial presentation of ten items over six randomized trials. Each item was presented for 0,75 seconds with a negligible inter-item interval. The presentation order of the items was randomized throughout the trials. Presentation was by means of a preprogrammed 16mm colour film. Items were scored for correct serial position. The auditory task consisted of the serial presentation of ten items over six randomized trials. The items were once again randomized throughout the trials with regards to presentation order. The presentation speed was one word per second. The presentation was by means of a pre-programmed tape. Items were scored for correct serial position. The visual task was common to both language groups whilst the other two tasks correlated with the language group. Thus, the items in the auditory and acoustic confusion tasks were different for each language but an attempt was made to control this variable. The tasks were conducted in the subjects home language which was either Xhosa or English. It was assumed that the RX group would demonstrate a greater incidence of EI, irrespective of the age of the subject, and that imagery would be reflected in the recall performance of the memory tasks. It was suggested that imagery may determine or encourage the mode of storage that the subject employed, which, in this case, would be the visual modality. If so then it would be expected that visual storage would circumvent the detrimental influence of acoustic confusability. The Xhosa university group (BS ) was an unknown quantity but was included to ascertain whether there were any marked differences between the group and the other two. The results revealed that imagery was in fact more prevalent in the Xhosa groups whilst the WS group demonstrated a complete lack of EI but did report the presence of pictorial imagery (PI). However, imagery did not appear to function as an aid to memory. It seemed, however, that in certain instances it correlated with visual encoding. Generally the Xhosa subjects, especially with regards to the visual tasks, tended to encode visually whilst the WS group encoded auditorily. With reference to recall performance, it was found that in all instances the WS group demonstrated superior recall followed by the BS and RX groups in that order. There was a significant difference in the strength of recall between each of the groups. The results of the auditory and visual tasks were interpreted within the STM principles developed in the West. It was found that the WS group adhered to these principles thereby justifying its position as a central group. The BS group followed a similar pattern with exception to the recency effect which was much weaker in their case. The RX group reported the absence of any storage and rehearsal strategies and this was reflected in their poor recall performance. They too were characterized by a very weak recency effect. The interesting point arose, however, when the auditory and visual recency effects were compared. According to Crawder and Norton (1969) the influence or the precategorical acoustic store (PAS) on recall should be reflected by a comparatively stronger auditory recency effect. This trend was observed in relation to the WS group but not to the Xhosa groups who tended to demonstrate a stronger visual recency effect. It was therefore, suspected that PAS did not operate with the same effectiveness with the Xhosa subjects. In fact it was suggested that in the case of the Xhosa subjects the visual peripheral store may be stronger than PAS. Contrary to expectation all three groups exhibited acoustic confusion. This was expected of the WS group as the subjects preferred auditory storage , but not of the Xhosa subjects who preferred visual storage. It was suggested however, that in the case of the Xhosa subjects the visual storage technique would have to be abandoned immediately prior to or during recall as recall was necessarily in the auditory modality. The outcome of the experiment generally confirmed Doab's conclusions as to the incidence of imagery and its relation with memory. However, due to the Xhosa preference for visual storage and their stronger visual recency effect, Sperling's model was slightly modified. Conrad 's findings were, of course, substantiated.
- Full Text:
- Date Issued: 1974
- Authors: Lewis, William Michael
- Date: 1974
- Subjects: Cross-cultural studies , Eidetic imagery , Short-term memory
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3141 , http://hdl.handle.net/10962/d1007182 , Cross-cultural studies , Eidetic imagery , Short-term memory
- Description: The complexity of behaviour necessitates a clear and concise approach in order to comprehend its functioning. An example of such an approach is highlighted by the field of cybernetics. Cybernetic models have been used extensively throughout the various fields of Psychology but perhaps never more so as in the case of short term memory (STM). This particular field abounds with behavioural models and research workers are constantly developing new models or testing the universality of existing models. Universal validity is essential to the strength of the behavioural principles inherent in any model but unfortunately such validity tends to be neglected. The present study attempts to reconcile this position with reference to specific models of STM, with relation to the phenomena of eidetic imagery (EI). Certain studies concerning the incidence of EI in illiterate Africans have produced results which are contradictory to those obtained in the Western culture. Two of the most important contradictions concern the fact that the illiterate Africans experienced the absence of an age parameter on the occurrence of such imagery and the fact that the incidence of imagery was more extensive in the African culture. A reason for these contradictions was sought and it was reasoned that as eidetic images have been closely linked with memory images, it may, therefore, be assumed that these particular cultures may use EI as an aid to memory in the absence of written material. Further, it would not be unreasonable to assume that this visual imagery may tend to dominate the STM process and thereby challenge the universality of those memory models that proposed acoustic domination of this process. No work has been done in investigating the memory process of the Africans. Thus, a study which did so would not only test the universality of specific memory models but would also possibly throw more light on the memory process itself. In this particular study there were three specific aims; (a) to ascertain the relative incidence of EI on a cross-cultural level, (b) to assess the influence of EI on the memory process, and (c) to ascertain the extent to which principles of STM developed in the West applied to the African groups. The groups concerned in the study comprised two Xhosa groups and a European group. The European group (WS) was drawn from a White Student population at Rhodes University and was regarded as a control group. The equivalent literate Xhosa group (BS) was drawn from a Black Student population at the University of Fort Hare. The illiterate Xhosa group (RX) was drawn from a population of Red Xhosa people in the Transkei. Four tasks were administered to the groups with the cross-cultural variable carefully controlled as much as possible. The following comprised the four tasks; (a) eidetic imagery (b) auditory serial recall (c) visual serial recall and (d) an acoustic confusable task. Each subject commenced with the eidetic imagery task and was then confronted with a random presentation of the other three tasks. The EI task began with an after image task which was foIlowed by three selected pictures which comprised the EI task. After each picture presentation the subject was closely questioned as to the presence of imagery. Scoring was of a subjective nature. The visual and acoustic confusion tasks constituted serial presentation of ten items over six randomized trials. Each item was presented for 0,75 seconds with a negligible inter-item interval. The presentation order of the items was randomized throughout the trials. Presentation was by means of a preprogrammed 16mm colour film. Items were scored for correct serial position. The auditory task consisted of the serial presentation of ten items over six randomized trials. The items were once again randomized throughout the trials with regards to presentation order. The presentation speed was one word per second. The presentation was by means of a pre-programmed tape. Items were scored for correct serial position. The visual task was common to both language groups whilst the other two tasks correlated with the language group. Thus, the items in the auditory and acoustic confusion tasks were different for each language but an attempt was made to control this variable. The tasks were conducted in the subjects home language which was either Xhosa or English. It was assumed that the RX group would demonstrate a greater incidence of EI, irrespective of the age of the subject, and that imagery would be reflected in the recall performance of the memory tasks. It was suggested that imagery may determine or encourage the mode of storage that the subject employed, which, in this case, would be the visual modality. If so then it would be expected that visual storage would circumvent the detrimental influence of acoustic confusability. The Xhosa university group (BS ) was an unknown quantity but was included to ascertain whether there were any marked differences between the group and the other two. The results revealed that imagery was in fact more prevalent in the Xhosa groups whilst the WS group demonstrated a complete lack of EI but did report the presence of pictorial imagery (PI). However, imagery did not appear to function as an aid to memory. It seemed, however, that in certain instances it correlated with visual encoding. Generally the Xhosa subjects, especially with regards to the visual tasks, tended to encode visually whilst the WS group encoded auditorily. With reference to recall performance, it was found that in all instances the WS group demonstrated superior recall followed by the BS and RX groups in that order. There was a significant difference in the strength of recall between each of the groups. The results of the auditory and visual tasks were interpreted within the STM principles developed in the West. It was found that the WS group adhered to these principles thereby justifying its position as a central group. The BS group followed a similar pattern with exception to the recency effect which was much weaker in their case. The RX group reported the absence of any storage and rehearsal strategies and this was reflected in their poor recall performance. They too were characterized by a very weak recency effect. The interesting point arose, however, when the auditory and visual recency effects were compared. According to Crawder and Norton (1969) the influence or the precategorical acoustic store (PAS) on recall should be reflected by a comparatively stronger auditory recency effect. This trend was observed in relation to the WS group but not to the Xhosa groups who tended to demonstrate a stronger visual recency effect. It was therefore, suspected that PAS did not operate with the same effectiveness with the Xhosa subjects. In fact it was suggested that in the case of the Xhosa subjects the visual peripheral store may be stronger than PAS. Contrary to expectation all three groups exhibited acoustic confusion. This was expected of the WS group as the subjects preferred auditory storage , but not of the Xhosa subjects who preferred visual storage. It was suggested however, that in the case of the Xhosa subjects the visual storage technique would have to be abandoned immediately prior to or during recall as recall was necessarily in the auditory modality. The outcome of the experiment generally confirmed Doab's conclusions as to the incidence of imagery and its relation with memory. However, due to the Xhosa preference for visual storage and their stronger visual recency effect, Sperling's model was slightly modified. Conrad 's findings were, of course, substantiated.
- Full Text:
- Date Issued: 1974
A forgotten frontier zone : settlements and reactions in the Stormberg area between 1820-1860
- Authors: Wagenaar, E J C
- Date: 1974
- Subjects: Eastern Cape (South Africa) -- History , South Africa -- History -- 1836-1909 , Cape of Good Hope (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2592 , http://hdl.handle.net/10962/d1007262
- Description: From Preface: In 1778 Joachim van Plettenberg declared the Fish River as boundary between the Trekboer and the Xhosa. The area between the lower reaches of the Fish and Kei Rivers was to become the main centre of conflict in nine frontier wars. It was here, too, that successive governors carried out experiments to stabilize land and people in the area. But after 1820, while official attention was focused on this trouble spot, a new and related zone of conflict was gradually and almost unnoticed opening up. This was in the north-east where the first encounters between Trekboer and Thembu were beginning to take place. By 1825 the spearhead of the Thembu, harassed by the amaNgwane raids, had migrated across the Kei River to settle south of the Stormberg in what is now the district of Queenstown. By this time the first Trekboers in their perennial search for water and pasturage had crossed the Stormberg Spruit to settle on the waste land north of the Stormberg. The history of the Stormberg area is predominantly an account of the interaction between these two peoples.
- Full Text:
- Date Issued: 1974
- Authors: Wagenaar, E J C
- Date: 1974
- Subjects: Eastern Cape (South Africa) -- History , South Africa -- History -- 1836-1909 , Cape of Good Hope (South Africa) -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2592 , http://hdl.handle.net/10962/d1007262
- Description: From Preface: In 1778 Joachim van Plettenberg declared the Fish River as boundary between the Trekboer and the Xhosa. The area between the lower reaches of the Fish and Kei Rivers was to become the main centre of conflict in nine frontier wars. It was here, too, that successive governors carried out experiments to stabilize land and people in the area. But after 1820, while official attention was focused on this trouble spot, a new and related zone of conflict was gradually and almost unnoticed opening up. This was in the north-east where the first encounters between Trekboer and Thembu were beginning to take place. By 1825 the spearhead of the Thembu, harassed by the amaNgwane raids, had migrated across the Kei River to settle south of the Stormberg in what is now the district of Queenstown. By this time the first Trekboers in their perennial search for water and pasturage had crossed the Stormberg Spruit to settle on the waste land north of the Stormberg. The history of the Stormberg area is predominantly an account of the interaction between these two peoples.
- Full Text:
- Date Issued: 1974
A share in pain and passion: the women of Synge's plays
- Authors: Finn, Stephen Michael
- Date: 1974
- Subjects: Synge, J. M. (John Millington), 1871-1909 , English literature -- Irish authors -- History and criticism , English drama -- Irish authors -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2295 , http://hdl.handle.net/10962/d1011865 , Synge, J. M. (John Millington), 1871-1909 , English literature -- Irish authors -- History and criticism , English drama -- Irish authors -- History and criticism
- Description: Synge's plays contain some of the most arresting figures in modern drama, his characterization second only to his unique language, the most striking feature of his writing. Of the men, only Christy Mahon and Martin Doul stand out but the women form a brilliant company usually overshadowing the other characters. Chapter 1, p. 1.
- Full Text:
- Date Issued: 1974
- Authors: Finn, Stephen Michael
- Date: 1974
- Subjects: Synge, J. M. (John Millington), 1871-1909 , English literature -- Irish authors -- History and criticism , English drama -- Irish authors -- History and criticism
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2295 , http://hdl.handle.net/10962/d1011865 , Synge, J. M. (John Millington), 1871-1909 , English literature -- Irish authors -- History and criticism , English drama -- Irish authors -- History and criticism
- Description: Synge's plays contain some of the most arresting figures in modern drama, his characterization second only to his unique language, the most striking feature of his writing. Of the men, only Christy Mahon and Martin Doul stand out but the women form a brilliant company usually overshadowing the other characters. Chapter 1, p. 1.
- Full Text:
- Date Issued: 1974
A structural investigation of the short stories of Katherine Mansfield with special reference to the idea of the true and false self
- Authors: Geldenhuys, M F
- Date: 1974
- Subjects: Mansfield, Katherine, 1888-1923 -- Criticism and interpretation , Short stories , Self in literatur
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2296 , http://hdl.handle.net/10962/d1011969
- Description: A survey of the available literature on Katherine Mansfield has shown that, in the five decades which have elapsed since the author's death, critical interest has gradually, but significantly, altered its direction. Despite the workmanlike assessments of such critics as David Daiches in Britain and Andre Maurois in France, and the recognition of her mastery of the short story form by such fellow practitioners of the art as H.E. Bates and Elizabeth Bowen, the mainstream of criticism tended, in the first decades after the author's death, to centre less upon the characteristics of the work itself than upon a cult- like fascination, initiated, perhaps, by the perceptive but over-interested pen of Middleton Murry. Only more recently has this tendency been superseded by a more rigorous scrutiny of the stories themselves; thus the excellence of the author 's technique has now become a major concern. Recent recognition has been accorded, too, to the fact that the stories were in the vanguard of their time with regard to the choice of, as well as the treatment of, theme. Intro. p. 1-2.
- Full Text:
- Date Issued: 1974
- Authors: Geldenhuys, M F
- Date: 1974
- Subjects: Mansfield, Katherine, 1888-1923 -- Criticism and interpretation , Short stories , Self in literatur
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2296 , http://hdl.handle.net/10962/d1011969
- Description: A survey of the available literature on Katherine Mansfield has shown that, in the five decades which have elapsed since the author's death, critical interest has gradually, but significantly, altered its direction. Despite the workmanlike assessments of such critics as David Daiches in Britain and Andre Maurois in France, and the recognition of her mastery of the short story form by such fellow practitioners of the art as H.E. Bates and Elizabeth Bowen, the mainstream of criticism tended, in the first decades after the author's death, to centre less upon the characteristics of the work itself than upon a cult- like fascination, initiated, perhaps, by the perceptive but over-interested pen of Middleton Murry. Only more recently has this tendency been superseded by a more rigorous scrutiny of the stories themselves; thus the excellence of the author 's technique has now become a major concern. Recent recognition has been accorded, too, to the fact that the stories were in the vanguard of their time with regard to the choice of, as well as the treatment of, theme. Intro. p. 1-2.
- Full Text:
- Date Issued: 1974
A study of the burrowing sandprawn Callianassa kraussi Stebbing (Crustacea - Decapoda - Thalassinidea)
- Authors: Forbes, Anthony Tonks
- Date: 1974
- Subjects: Estuarine biology -- South Africa Shrimps -- South Africa Decapoda (Crustacea) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5850 , http://hdl.handle.net/10962/d1011866
- Description: The distribution of Callianassa kraussi in southern Africa extends from Lamberts Bay on the west coast to San Martinho in Mocambique. This represents a northerly extension of the range from the previous known limit of Inhaca Island. In this area 59 localities were visited and records obtained for an additional 16. Three areas were selected for detailed study. These were the west Kleinemonde estuary, which is normally closed off from the sea by a sand bar and the open Swartkops estuary both on the southeastern Cape coast, and the Swartvlei system, which consists of a lake connected to the sea by a channel which closes intermittently, on the southern Cape coast. The nature of the burrows constructed by C. kraussi was investigated in these areas. Burrow complexes may have up to nine entrances but more commonly two to four. Laboratory studies suggest that the number of entrances does not exceed the number of prawns present and consequently burrow opening counts will give an estimate of population density. Water movement can result in the closing off of burrows while strong water and sand movement will exclude C.kraussi from an area. C.kraussi is also excluded from areas which have very coarse substrates. A three year regular sampling program showed that C.kraussi breeds mainly in winter/spring with a smaller breeding peak in summer. Egg development time at 20°C in a salinity of 35° /₀₀ is 30-33 days. There are two larval stages which last 3-5 days. Development time of the eggs is tripled at temperatures of 13-15°C while larval development time is extended to 9-14 days. Development is possibly slightly accelerated at 25 ± 3°C but the number of eggs hatching is markedly reduced. Larval development times were similar to those at 20° and 35°/₀₀. There are no planktonic larval stages. Growth was more rapid and greater size was attained in the open Swartkops estuary than in the closed Kleinemonde estuary. Prawns hatching in winter/spring breed for the first time in the following summer at an age of about 16 months and then again in the following winter/spring at an age of about 2 years. Prawns hatching in summer breed in the following winter at an age of about 18 months and then again in the immediately following summer. Longevity in both sexes is about 2 years. Dispersal is accomplished by migration of the post-larval juvenile phases at an age of 3-5 months. Non-selfmaintaining populations exist in areas where salinities are too low to permit breeding. Population densities were found to vary markedly in different areas. Investigations of osmotic and ionic regulation showed that C.kraussi is a strong hyper-regulator and thus distinct from any other known species in the genus. Volume regulatory ability is well developed and depends on variable rates of urine production. Salt loss in dilutions occurs almost equally via the gills and the urine. The general responses of C.kraussi to dilutions of sea water are discussed. Various suggestions for conservation measures based on the distribution and iife cycle of C.kraussi were made. The factors affecting the distribution of C.kraussi are discussed. The problem of the larval development in C.kraussi was discussed in relation to reviews of larval types of benthic invertebrates. The importance of the burrow, the possible route by which C.kraussi has invaded estuaries and the differences between open and closed estuaries as shown by the effects on C.kraussi were discussed.
- Full Text:
- Date Issued: 1974
- Authors: Forbes, Anthony Tonks
- Date: 1974
- Subjects: Estuarine biology -- South Africa Shrimps -- South Africa Decapoda (Crustacea) -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5850 , http://hdl.handle.net/10962/d1011866
- Description: The distribution of Callianassa kraussi in southern Africa extends from Lamberts Bay on the west coast to San Martinho in Mocambique. This represents a northerly extension of the range from the previous known limit of Inhaca Island. In this area 59 localities were visited and records obtained for an additional 16. Three areas were selected for detailed study. These were the west Kleinemonde estuary, which is normally closed off from the sea by a sand bar and the open Swartkops estuary both on the southeastern Cape coast, and the Swartvlei system, which consists of a lake connected to the sea by a channel which closes intermittently, on the southern Cape coast. The nature of the burrows constructed by C. kraussi was investigated in these areas. Burrow complexes may have up to nine entrances but more commonly two to four. Laboratory studies suggest that the number of entrances does not exceed the number of prawns present and consequently burrow opening counts will give an estimate of population density. Water movement can result in the closing off of burrows while strong water and sand movement will exclude C.kraussi from an area. C.kraussi is also excluded from areas which have very coarse substrates. A three year regular sampling program showed that C.kraussi breeds mainly in winter/spring with a smaller breeding peak in summer. Egg development time at 20°C in a salinity of 35° /₀₀ is 30-33 days. There are two larval stages which last 3-5 days. Development time of the eggs is tripled at temperatures of 13-15°C while larval development time is extended to 9-14 days. Development is possibly slightly accelerated at 25 ± 3°C but the number of eggs hatching is markedly reduced. Larval development times were similar to those at 20° and 35°/₀₀. There are no planktonic larval stages. Growth was more rapid and greater size was attained in the open Swartkops estuary than in the closed Kleinemonde estuary. Prawns hatching in winter/spring breed for the first time in the following summer at an age of about 16 months and then again in the following winter/spring at an age of about 2 years. Prawns hatching in summer breed in the following winter at an age of about 18 months and then again in the immediately following summer. Longevity in both sexes is about 2 years. Dispersal is accomplished by migration of the post-larval juvenile phases at an age of 3-5 months. Non-selfmaintaining populations exist in areas where salinities are too low to permit breeding. Population densities were found to vary markedly in different areas. Investigations of osmotic and ionic regulation showed that C.kraussi is a strong hyper-regulator and thus distinct from any other known species in the genus. Volume regulatory ability is well developed and depends on variable rates of urine production. Salt loss in dilutions occurs almost equally via the gills and the urine. The general responses of C.kraussi to dilutions of sea water are discussed. Various suggestions for conservation measures based on the distribution and iife cycle of C.kraussi were made. The factors affecting the distribution of C.kraussi are discussed. The problem of the larval development in C.kraussi was discussed in relation to reviews of larval types of benthic invertebrates. The importance of the burrow, the possible route by which C.kraussi has invaded estuaries and the differences between open and closed estuaries as shown by the effects on C.kraussi were discussed.
- Full Text:
- Date Issued: 1974
A study of the properties and methods of analysis of high molecular weight N-nitrosamines
- Authors: Kelly, Felix Thomas
- Date: 1974 , 2013-10-29
- Subjects: Nitrosoamines , Chemistry, Physical and theoretical
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4421 , http://hdl.handle.net/10962/d1006878 , Nitrosoamines , Chemistry, Physical and theoretical
- Description: Various high molecular weight dialkylnitrosamines were prepared including, for the first time, methyl-n-octadecylnitrosamine and di-n-dodecylnitrosamine. The infrared, ultraviolet and mass spectra of a selection of these compounds were recorded and studied. Gel permeation chromatography was used for the isolation of individual nitrosamines in standard nitrosamine mixtures, while ion-exchange chromatography effected complete clean-up of amine-contaminated nitrosamine solutions. Thin-layer and gas-liquid chromatographic methods were developed for the detection, separation and analysis of nanogram quantities of these lipophilic nitrosamines. In addition the above chromatographic systems were used for the analysis of distillates of spiked wheat flour samples. High recoveries of dicyclopentylnitrosamine, di-n-heptylnitrosamine and di-n-octylnitrosamine, from the spiked wheat flour samples, were achieved using a specially developed freeze-drying/vacuum distillation technique, the distillates obtained being relatively free from major contaminants. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1974
- Authors: Kelly, Felix Thomas
- Date: 1974 , 2013-10-29
- Subjects: Nitrosoamines , Chemistry, Physical and theoretical
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4421 , http://hdl.handle.net/10962/d1006878 , Nitrosoamines , Chemistry, Physical and theoretical
- Description: Various high molecular weight dialkylnitrosamines were prepared including, for the first time, methyl-n-octadecylnitrosamine and di-n-dodecylnitrosamine. The infrared, ultraviolet and mass spectra of a selection of these compounds were recorded and studied. Gel permeation chromatography was used for the isolation of individual nitrosamines in standard nitrosamine mixtures, while ion-exchange chromatography effected complete clean-up of amine-contaminated nitrosamine solutions. Thin-layer and gas-liquid chromatographic methods were developed for the detection, separation and analysis of nanogram quantities of these lipophilic nitrosamines. In addition the above chromatographic systems were used for the analysis of distillates of spiked wheat flour samples. High recoveries of dicyclopentylnitrosamine, di-n-heptylnitrosamine and di-n-octylnitrosamine, from the spiked wheat flour samples, were achieved using a specially developed freeze-drying/vacuum distillation technique, the distillates obtained being relatively free from major contaminants. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1974
After the visit of a Greek poet to the Transvaal
- Authors: Mann, Chris
- Date: 1974
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/459559 , vital:75842 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_457
- Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
- Full Text:
- Date Issued: 1974
- Authors: Mann, Chris
- Date: 1974
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/459559 , vital:75842 , https://journals.co.za/doi/epdf/10.10520/AJA00284459_457
- Description: New Coin is one of South Africa's most established and influential poetry journals. It publishes poetry, and poetry-related reviews, commentary and interviews. New Coin places a particular emphasis on evolving forms and experimental use of the English language in poetry in the South African context. In this sense it has traced the most exciting trends and currents in contemporary poetry in South Africa for a decade of more. The journal is published twice a year in June and December by the Institute for the Study of English in Africa (ISEA), Rhodes University.
- Full Text:
- Date Issued: 1974
Albany Rugby Football Club 1st XV, 1974
- Date: 1974
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50701 , vital:26018 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/M 6702
- Description: Albany Rugby Football Club 1st XV 1974, 1st XV – 1974,Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Framed photographs against wall in background, President, Club Captain and Coach wearing suits, Captain holding rugby ball with “1974” on it, Players standing have arms by side, Players sitting have hands in lap, Standing (left to right): A Marais, R. Snow, R. Green, B. Shone, P. van Rensburg, S. Long, D. J. Mills, S. Hill, Sitting: (left to right): L. Webster, R. Carlson, J. Place (President), B. Carlson (Captain), P. Long (Club-Captain), Major Bakkes (Coach), R. Moss, Front (left to right): A. Austin, C. Reed, Absent: C. Pascoe.
- Full Text: false
- Date Issued: 1974
- Date: 1974
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50701 , vital:26018 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/M 6702
- Description: Albany Rugby Football Club 1st XV 1974, 1st XV – 1974,Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Framed photographs against wall in background, President, Club Captain and Coach wearing suits, Captain holding rugby ball with “1974” on it, Players standing have arms by side, Players sitting have hands in lap, Standing (left to right): A Marais, R. Snow, R. Green, B. Shone, P. van Rensburg, S. Long, D. J. Mills, S. Hill, Sitting: (left to right): L. Webster, R. Carlson, J. Place (President), B. Carlson (Captain), P. Long (Club-Captain), Major Bakkes (Coach), R. Moss, Front (left to right): A. Austin, C. Reed, Absent: C. Pascoe.
- Full Text: false
- Date Issued: 1974
Albany Rugby Football Club 1st XV, 1974
- Date: 1974
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50710 , vital:26017 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/M 6701
- Description: Albany Rugby Football Club 1st XV 1974, Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Framed photographs against wall in background, President, Club Captain and Coach wearing suits, Captain holding rugby ball with “1974” on it, Players standing have arms by side, Players sitting have hands in lap, Standing (left to right): A Marais, R. Snow, R. Green, B. Shone, P. van Rensburg, S. Long, D. J. Mills, S. Hill, Sitting: (left to right): L. Webster, R. Carlson, J. Place (President), B. Carlson (Captain), P. Long (Club-Captain), Major Bakkes (Coach), R. Moss, Front (left to right): A. Austin, C. Reed. Absent: C. Pascoe.
- Full Text: false
- Date Issued: 1974
- Date: 1974
- Subjects: Rugby football -- South Africa -- Eastern Cape -- Photographs , Albany Rugby Football Club -- Photographs
- Type: still image
- Identifier: http://hdl.handle.net/10962/50710 , vital:26017 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , PIC/M 6701
- Description: Albany Rugby Football Club 1st XV 1974, Team photograph with rugby/football players, in rugby uniform, Group photograph, Black and white photograph, Indoor photograph, Framed photographs against wall in background, President, Club Captain and Coach wearing suits, Captain holding rugby ball with “1974” on it, Players standing have arms by side, Players sitting have hands in lap, Standing (left to right): A Marais, R. Snow, R. Green, B. Shone, P. van Rensburg, S. Long, D. J. Mills, S. Hill, Sitting: (left to right): L. Webster, R. Carlson, J. Place (President), B. Carlson (Captain), P. Long (Club-Captain), Major Bakkes (Coach), R. Moss, Front (left to right): A. Austin, C. Reed. Absent: C. Pascoe.
- Full Text: false
- Date Issued: 1974
Aspects of the theory of human capital and its application to South African economic development
- Authors: Bates, Terrence
- Date: 1974
- Subjects: Human capital -- South Africa , South Africa -- Economic conditions -- 1961-1991
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1064 , http://hdl.handle.net/10962/d1007608 , Human capital -- South Africa , South Africa -- Economic conditions -- 1961-1991
- Description: Human capital is an important economic concept. The significance of human resource development, in the form of both education and health, has long been realised and was stressed even in the writings of the early economists. Introduction, p.1
- Full Text:
- Date Issued: 1974
- Authors: Bates, Terrence
- Date: 1974
- Subjects: Human capital -- South Africa , South Africa -- Economic conditions -- 1961-1991
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1064 , http://hdl.handle.net/10962/d1007608 , Human capital -- South Africa , South Africa -- Economic conditions -- 1961-1991
- Description: Human capital is an important economic concept. The significance of human resource development, in the form of both education and health, has long been realised and was stressed even in the writings of the early economists. Introduction, p.1
- Full Text:
- Date Issued: 1974
Decorative aspects of reality with reference to sociological painting
- Authors: Clark, Dorothy
- Date: 1974
- Subjects: Decorative arts
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2474 , http://hdl.handle.net/10962/d1010501
- Description: The writer could not blame the reader for finding the title to this essay couched in somewhat academic terms. It must be said immediately that the title is a fake -- or that the following essay is a fake; the title has pretensions to the academic -- the essay has not. All academicism no longer has an independent existence -- it operates by formulae, is mechanical, uses faked sensations and vicarious experience and borrows its tricks and themes from a mature, established culture close at hand. This ' culture's life's blood is looted, given new twists, watered down and served up in academic terms. For these reasons, academicism and Kitsch are the same -- both change according to style and yet are always the same; both are the epitome of all that is spurious in our time. So, academicism could be said to be the 'stuffed shirt-front' for Kitsch. Preamble, p. 1.
- Full Text:
- Date Issued: 1974
- Authors: Clark, Dorothy
- Date: 1974
- Subjects: Decorative arts
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2474 , http://hdl.handle.net/10962/d1010501
- Description: The writer could not blame the reader for finding the title to this essay couched in somewhat academic terms. It must be said immediately that the title is a fake -- or that the following essay is a fake; the title has pretensions to the academic -- the essay has not. All academicism no longer has an independent existence -- it operates by formulae, is mechanical, uses faked sensations and vicarious experience and borrows its tricks and themes from a mature, established culture close at hand. This ' culture's life's blood is looted, given new twists, watered down and served up in academic terms. For these reasons, academicism and Kitsch are the same -- both change according to style and yet are always the same; both are the epitome of all that is spurious in our time. So, academicism could be said to be the 'stuffed shirt-front' for Kitsch. Preamble, p. 1.
- Full Text:
- Date Issued: 1974