A geographical study of the Cape Midlands and Eastern Karoo area with reference to the physiography and elements of land use
- Authors: Badenhorst, J J
- Date: 1969 , 2013-11-14
- Subjects: Land use -- South Africa , Geomorphology -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4867 , http://hdl.handle.net/10962/d1007581 , Land use -- South Africa , Geomorphology -- South Africa
- Description: The subject has been approached in the conventional geographic manner in successive chapters, Relief, Geology, Soil, Climate, etc. In practice, the relationship between geographic factors and land use is so close that it is usually very difficult to separate the one from the other. When there is any reference to a specific relationship in any chapter, it must be borne in mind that one must always take the other geographic factors into account. In this study the stress falls on an evaluation of the present land use. Even if there is no recommendation regarding the way in which the land should be used, this survey can still be used as the basis for future planning. Intro. p.viii , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1969
- Authors: Badenhorst, J J
- Date: 1969 , 2013-11-14
- Subjects: Land use -- South Africa , Geomorphology -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:4867 , http://hdl.handle.net/10962/d1007581 , Land use -- South Africa , Geomorphology -- South Africa
- Description: The subject has been approached in the conventional geographic manner in successive chapters, Relief, Geology, Soil, Climate, etc. In practice, the relationship between geographic factors and land use is so close that it is usually very difficult to separate the one from the other. When there is any reference to a specific relationship in any chapter, it must be borne in mind that one must always take the other geographic factors into account. In this study the stress falls on an evaluation of the present land use. Even if there is no recommendation regarding the way in which the land should be used, this survey can still be used as the basis for future planning. Intro. p.viii , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1969
Psigobiografiese persoonlikheidsbeskrywing van Generaal Christiaan de Wet
- Authors: Henning, Riana
- Date: 2010
- Subjects: De Wet, Christiaan Rudolf, 1854-1922 Psychology -- Biographical methods Psychoanalysis Big Five model Politicians -- Psychology South Africa -- Politics and government -- 1836-1909 South Africa -- Politics and government -- 1909-1948
- Language: Afrikaans
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2990 , http://hdl.handle.net/10962/d1002499
- Description: Hierdie is 'n psigobiografiese studie van Generaal Christiaan Rudolph de Wet. 'n Psigobiografiese studie is die bestudering van 'n persoon se volledige lewe met die doel om die persoon beter te verstaan. Psigobiografiese navorsing maak gebruik van psigologiese teorieë wat aangewend word om die biografiese data van 'n persoon se lewe te beskryf en moontlik ook te verklaar. Die individu wat bestudeer word, is gewoonlik 'n bekende, invloedryke, navolgenswaardige, interessante of modelfiguur. Daar is tans 'n oplewing in die veld van psigobiografiese studies, maar daar word nog steeds nie genoeg in die akademiese veld gedoen om psigobiografiese studies te bevorder nie. De Wet (1854-1922) is vir hierdie studie gekies omdat hy 'n interessante, dog komplekse figuur was. Hy het veral tydens die Anglo-Boereoorlog in 1899-1902 bekendheid verwerf. As 45-jarige man het De Wet in die Anglo-Boereoorlog geveg en vinnig opgang as 'n militêre leier gemaak. Sy vindingryke ontsnappingspogings het die Britse magte hoofbrekens besorg. Wat De Wet verder uniek maak, is dat hy met net drie maande skoolopleiding in die parlement gedien het, as president verkies is, die hoogste gesag in die Verdedigingsmag gehad het en 'n boek oor sy oorlogsherinneringe geskryf het. Alhoewel daar akademiese werke oor De Wet bestaan, is daar tot op hede nog geen psigobiografiese studie oor hom gedoen nie. Die doel van die studie was om die mens agter die legende na vore te bring. Daar is ook gepoog om moontlike antwoorde en verklarings op onbeantwoorde vrae te gee. Die studie het van beide kwalitatiewe en kwantitatiewe data gebruik gemaak en kan as 'n psigobiografiese gevalstudie beskryf word. Die Vyf-faktor model van Costa en McCrae (1992) is op die biografiese data van De Wet toegepas om sodoende sy persoonlikheidseienskappe te beskryf. Die bevindinge het interessante persoonlikheidseienskappe van De Wet deur middel van die Vyf-faktor model aan die lig gebring. Volgens die kwalitatiewe navorsingsbevindinge was De Wet 'n vyandige, aksie-gedrewe, bevoegde, prestasie-strewende, selfgedissiplineerde, warm, openhartige, saggeaarde en beskeie persoon. Die kwalitatiewe en kwantitatiewe data-ontledings het uiteenlopende persoonlikheidskenmerke by De Wet geïdentifiseer. Die grootste verskille het by die fasette warmte, openhartigheid en altruïsme voorgekom. Die waarde van die studie is dat 'n wetenskaplike persoonlikheidsontleding van De Wet gedoen is. Dit is ook die eerste studie waar 'n teoretiese model op De Wet se persoonlikheid toegepas is. Alhoewel die studie sekere tekortkominge toon, beklemtoon dit terselfdertyd die wenslikheid daarvan om alternatiewe modelle te gebruik tydens die ontleding van persoonlikheidskenmerke. Die studie dui ook op die behoefte aan verdere navorsing, byvoorbeeld soortgelyke ontledings en vergelykings van die persoonlikhede van ander militêre bevelvoerders (De la Rey, Smuts, Beyers, Hertzog).
- Full Text:
- Date Issued: 2010
- Authors: Henning, Riana
- Date: 2010
- Subjects: De Wet, Christiaan Rudolf, 1854-1922 Psychology -- Biographical methods Psychoanalysis Big Five model Politicians -- Psychology South Africa -- Politics and government -- 1836-1909 South Africa -- Politics and government -- 1909-1948
- Language: Afrikaans
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2990 , http://hdl.handle.net/10962/d1002499
- Description: Hierdie is 'n psigobiografiese studie van Generaal Christiaan Rudolph de Wet. 'n Psigobiografiese studie is die bestudering van 'n persoon se volledige lewe met die doel om die persoon beter te verstaan. Psigobiografiese navorsing maak gebruik van psigologiese teorieë wat aangewend word om die biografiese data van 'n persoon se lewe te beskryf en moontlik ook te verklaar. Die individu wat bestudeer word, is gewoonlik 'n bekende, invloedryke, navolgenswaardige, interessante of modelfiguur. Daar is tans 'n oplewing in die veld van psigobiografiese studies, maar daar word nog steeds nie genoeg in die akademiese veld gedoen om psigobiografiese studies te bevorder nie. De Wet (1854-1922) is vir hierdie studie gekies omdat hy 'n interessante, dog komplekse figuur was. Hy het veral tydens die Anglo-Boereoorlog in 1899-1902 bekendheid verwerf. As 45-jarige man het De Wet in die Anglo-Boereoorlog geveg en vinnig opgang as 'n militêre leier gemaak. Sy vindingryke ontsnappingspogings het die Britse magte hoofbrekens besorg. Wat De Wet verder uniek maak, is dat hy met net drie maande skoolopleiding in die parlement gedien het, as president verkies is, die hoogste gesag in die Verdedigingsmag gehad het en 'n boek oor sy oorlogsherinneringe geskryf het. Alhoewel daar akademiese werke oor De Wet bestaan, is daar tot op hede nog geen psigobiografiese studie oor hom gedoen nie. Die doel van die studie was om die mens agter die legende na vore te bring. Daar is ook gepoog om moontlike antwoorde en verklarings op onbeantwoorde vrae te gee. Die studie het van beide kwalitatiewe en kwantitatiewe data gebruik gemaak en kan as 'n psigobiografiese gevalstudie beskryf word. Die Vyf-faktor model van Costa en McCrae (1992) is op die biografiese data van De Wet toegepas om sodoende sy persoonlikheidseienskappe te beskryf. Die bevindinge het interessante persoonlikheidseienskappe van De Wet deur middel van die Vyf-faktor model aan die lig gebring. Volgens die kwalitatiewe navorsingsbevindinge was De Wet 'n vyandige, aksie-gedrewe, bevoegde, prestasie-strewende, selfgedissiplineerde, warm, openhartige, saggeaarde en beskeie persoon. Die kwalitatiewe en kwantitatiewe data-ontledings het uiteenlopende persoonlikheidskenmerke by De Wet geïdentifiseer. Die grootste verskille het by die fasette warmte, openhartigheid en altruïsme voorgekom. Die waarde van die studie is dat 'n wetenskaplike persoonlikheidsontleding van De Wet gedoen is. Dit is ook die eerste studie waar 'n teoretiese model op De Wet se persoonlikheid toegepas is. Alhoewel die studie sekere tekortkominge toon, beklemtoon dit terselfdertyd die wenslikheid daarvan om alternatiewe modelle te gebruik tydens die ontleding van persoonlikheidskenmerke. Die studie dui ook op die behoefte aan verdere navorsing, byvoorbeeld soortgelyke ontledings en vergelykings van die persoonlikhede van ander militêre bevelvoerders (De la Rey, Smuts, Beyers, Hertzog).
- Full Text:
- Date Issued: 2010
"The wife of Lucifer" : women and evil in Charles Dickens
- Authors: Ebelthite, Candice Axell
- Date: 2002
- Subjects: Dickens, Charles, 1812-1870 -- Characters -- Women Evil in literature Women in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2189 , http://hdl.handle.net/10962/d1002231
- Description: This thesis examines Dickens's presentation of evil women. In the course of my reading I discovered that most of the evil women in his novels are mothers, or mother-figures, a finding which altered the nature of my interpretation and led to closer examination of these characters, rather than the prostitutes and criminals who may have been viewed negatively by Nineteenth century society and thereby condemned as evil. Among the many unsympathetically portrayed mothers and mother-figures in Dickens's works, the three that are most interesting are Lady Dedlock, Miss Havisham, and Mrs Skewton. Madame Defarge initiates the discussion, however, as a seminal figure among the many evil women in the novels. Psychoanalytical and socio-historic readings grounded in Nineteenth century conceptions of womanhood provide background material for this thesis. Though useful and informative, however, these areas of study are not sufficient in themselves. The theory that shapes the arguments of this thesis is defined by Steven Cohan, who argues strongly that the demand for psychological coherence as a requisite of character obscures the imaginative power of character as textual construct, and who both refutes and develops character theory as it is argued by Baruch Hochman. Cohan's theory is also finally closer to that outlined by Thomas Docherty, who provides a complex reading of character as ultimately "unknowable".
- Full Text:
- Date Issued: 2002
- Authors: Ebelthite, Candice Axell
- Date: 2002
- Subjects: Dickens, Charles, 1812-1870 -- Characters -- Women Evil in literature Women in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2189 , http://hdl.handle.net/10962/d1002231
- Description: This thesis examines Dickens's presentation of evil women. In the course of my reading I discovered that most of the evil women in his novels are mothers, or mother-figures, a finding which altered the nature of my interpretation and led to closer examination of these characters, rather than the prostitutes and criminals who may have been viewed negatively by Nineteenth century society and thereby condemned as evil. Among the many unsympathetically portrayed mothers and mother-figures in Dickens's works, the three that are most interesting are Lady Dedlock, Miss Havisham, and Mrs Skewton. Madame Defarge initiates the discussion, however, as a seminal figure among the many evil women in the novels. Psychoanalytical and socio-historic readings grounded in Nineteenth century conceptions of womanhood provide background material for this thesis. Though useful and informative, however, these areas of study are not sufficient in themselves. The theory that shapes the arguments of this thesis is defined by Steven Cohan, who argues strongly that the demand for psychological coherence as a requisite of character obscures the imaginative power of character as textual construct, and who both refutes and develops character theory as it is argued by Baruch Hochman. Cohan's theory is also finally closer to that outlined by Thomas Docherty, who provides a complex reading of character as ultimately "unknowable".
- Full Text:
- Date Issued: 2002
Author, ideology and publisher a symbiotic relationship : Lovedale Missionary Press and early Black writing in South Africa: with specific reference to the critical writings of H.I.E. Dlomo
- Authors: Midgley, Henry Peter
- Date: 1994
- Subjects: Shepherd, Robert H W (Robert Henry Wishart), 1888-1971 Dhlomo, H I E (Herbert I E), 1903-1956 Rhodes University Dissertations African literature Lovedale Institution South African literature -- Black authors -- History and criticism South African literature (English) -- History and criticism Politics and literature -- South Africa -- History -- 20th century Press and politics -- South Africa -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2241 , http://hdl.handle.net/10962/d1002284
- Description: The specific instances of R.H.W. Shepherd and H.I.E. Dhlomo are used in this thesis to investigate some of the many factors that influence the formation of a colonial literature, such as politics, social structures and personal ideals. By isolating the Lovedale Mission Press ~s a "contact zone" - a·place where the cultures of the colonizer and the colonized come into direct contact with each other - it is possible to trace how the interaction between these cultures shaped the writing of a particular African writer, H.I.E. Dhlomo. This is done through an analysis of historical factors that shaped the policy of the Lovedale Mission Press in the twentieth century: the development of liberalism in South Africa, the·role of the missionary in African education, the function ofa liberal magazine such as The South African Outlook and the appointment of an ambitious missionary, R.I.W. Shepherd, to the position of Director of Publications. This necessarily included a study of Shepherd's vision of African literature. On the other hand, this study takes cognisance of the factors that shaped Herbert Dhlomo's vision of literature: the development of African nationalism, the entrenchment of segregation as a politial doctrine, and most importantly, his struggle to have his creative writing published by the Lovedale Press. It is shown how Shepherd's vision of what African literature should entail contrasted with Dhlomo's, and how, as a result, Dhlomo deliberately structured his critical writing as a response to Shepherd's Eurocentric approach to African literature.
- Full Text:
- Date Issued: 1994
- Authors: Midgley, Henry Peter
- Date: 1994
- Subjects: Shepherd, Robert H W (Robert Henry Wishart), 1888-1971 Dhlomo, H I E (Herbert I E), 1903-1956 Rhodes University Dissertations African literature Lovedale Institution South African literature -- Black authors -- History and criticism South African literature (English) -- History and criticism Politics and literature -- South Africa -- History -- 20th century Press and politics -- South Africa -- History
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2241 , http://hdl.handle.net/10962/d1002284
- Description: The specific instances of R.H.W. Shepherd and H.I.E. Dhlomo are used in this thesis to investigate some of the many factors that influence the formation of a colonial literature, such as politics, social structures and personal ideals. By isolating the Lovedale Mission Press ~s a "contact zone" - a·place where the cultures of the colonizer and the colonized come into direct contact with each other - it is possible to trace how the interaction between these cultures shaped the writing of a particular African writer, H.I.E. Dhlomo. This is done through an analysis of historical factors that shaped the policy of the Lovedale Mission Press in the twentieth century: the development of liberalism in South Africa, the·role of the missionary in African education, the function ofa liberal magazine such as The South African Outlook and the appointment of an ambitious missionary, R.I.W. Shepherd, to the position of Director of Publications. This necessarily included a study of Shepherd's vision of African literature. On the other hand, this study takes cognisance of the factors that shaped Herbert Dhlomo's vision of literature: the development of African nationalism, the entrenchment of segregation as a politial doctrine, and most importantly, his struggle to have his creative writing published by the Lovedale Press. It is shown how Shepherd's vision of what African literature should entail contrasted with Dhlomo's, and how, as a result, Dhlomo deliberately structured his critical writing as a response to Shepherd's Eurocentric approach to African literature.
- Full Text:
- Date Issued: 1994
The growth and reproduction of the freshwater limpet Burnupia stenochorias (Pulmonata, Ancylidae), and an evaluation of its use as an ecotoxicology indicator in whole effluent testing
- Davies-Coleman, H D (Heather D)
- Authors: Davies-Coleman, H D (Heather D)
- Date: 2002
- Subjects: Ancylidae Effluent quality Toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5703 , http://hdl.handle.net/10962/d1005389
- Description: For the protection of the ecological Reserve in South Africa, the proposed introduction of compulsory toxicity testing in the licensing of effluent discharges necessitates the development of whole effluent toxicity testing. The elucidation of the effects of effluent on the local indigenous populations of organisms is essential before hazard and risk assessment can be undertaken. The limpet Burnupia stenochorias, prevalent in the Eastern Cape of South Africa, was chosen to represent the freshwater molluscs as a potential toxicity indicator. Using potassium dichromate (as a reference toxicant) and a textile whole effluent, the suitability of B. stenochorias was assessed under both acute and chronic toxicity conditions in the laboratory. In support of the toxicity studies, aspects of the biology of B. stenochorias were investigated under both natural and laboratory conditions. Using Principal Component and Discriminant Function Analyses, the relative shell morphometrics of three feral populations of B. stenochorias were found to vary. Length was shown to adequately represent growth of the shell, although the inclusion of width measurements is more statistically preferable. Two of the feral populations, one in impacted water, were studied weekly for 52 weeks to assess natural population dynamics. Based on the Von Bertalanffy Growth Equation, estimates of growth and longevity were made for this species, with growth highly seasonal. Age is not easily discerned from shell size. Egg laying occurred all year round, with early summer (peak egg lay), mid summer (a second, smaller peak in egg lay), and winter (limited presence of eggs) phases. In toxicity testing, consideration is given to the choice of the test organism based on age and sexual development. Consequently, the sexual development of B. stenochorias relative to shell length was determined with the aid of histological examinations of transverse sections of limpets, of all sizes, collected over one year. Limpets less than 3mm shell length were found to be immature in the development of the oocytes and spermatozoa, and were later chosen for acute toxicity tests. A laboratory diet was developed, for both culturing and maintaining of the limpets during toxicity tests; however, the diet requires optimisation. Under laboratory conditions, growth was linear, and individual fecundity highly variable. Successful methods for the collection of limpets from naturally occurring populations, and their acclimation to the laboratory were developed. Three B. stenochorias populations, representing different hydrological and water quality conditions, were compared to a laboratory population (maintained for three years) in their responses to the textile whole effluent and potassium dichromate. Under acute conditions, variability of mortality between limpet populations and between seasons was consistent with acceptable international standards. However, seasonal differences between feral limpets were apparent, with early summer limpets significantly more susceptible to both potassium dichromate and textile effluent than winter limpets. Although mortality occurred within the effluent at all concentrations, no 96 hour LC₅₀ values were obtained. The chronic toxicity effects of the textile whole effluent were assessed over the entire life cycle of B. stenochorias, based on survival, growth and reproductive effects. Lower concentrations of effluent (# 10%) gave greater variability of responses and toxicity than higher concentrations, with a 43 day LC₅₀ of 3.9% effluent. The No Observed Effect Concentrations for survival (over 43 days) were calculated in consecutive years as 0.1% and 1% effluent. Survival is considered a useful tool for determining toxicity endpoints using B. stenochorias. Limpet growth remained linear in effluent, with an apparent stimulation of growth at the 3-10% effluent concentration, confusing the toxicity and variability assessments. The possible addition of nutrients from the effluent points to either a potential inadequacy of the food quality provided in the chronic assessment, or the presence in the effluent of growth stimulants. Growth was also found to be too variable to allow adequate statistical conclusions about the toxicity of the effluent, although it is suggested that growth may be useful in the assessment of single compounds. Despite large individual variability in fecundity, statistical differences were discernible between effluent concentrations. The application of fecundity of B. stenochorias in hazard assessment therefore warrants further investigation. It was concluded that an assessment of textile whole effluent toxicity to B. stenochorias over an entire life cycle, and an F1 generation, is unnecessary. The development of the bucket/plastic bag method for both acute and chronic toxicity assessment of B. stenochorias was useful. In the final assessment of the usefulness of B. stenochorias as a toxicity indicator, toxicity endpoints were compared with those of the standard laboratory organism Daphnia pulex. Both in acute and chronic toxicity, B. stenochorias was found to be more sensitive. B. stenochorias is therefore considered valuable as a South African freshwater molluscan ecotoxicological indicator, with a place in hazard assessment, although further development and research is necessary before the limpet can be effectively used.
- Full Text:
- Date Issued: 2002
- Authors: Davies-Coleman, H D (Heather D)
- Date: 2002
- Subjects: Ancylidae Effluent quality Toxicity testing
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5703 , http://hdl.handle.net/10962/d1005389
- Description: For the protection of the ecological Reserve in South Africa, the proposed introduction of compulsory toxicity testing in the licensing of effluent discharges necessitates the development of whole effluent toxicity testing. The elucidation of the effects of effluent on the local indigenous populations of organisms is essential before hazard and risk assessment can be undertaken. The limpet Burnupia stenochorias, prevalent in the Eastern Cape of South Africa, was chosen to represent the freshwater molluscs as a potential toxicity indicator. Using potassium dichromate (as a reference toxicant) and a textile whole effluent, the suitability of B. stenochorias was assessed under both acute and chronic toxicity conditions in the laboratory. In support of the toxicity studies, aspects of the biology of B. stenochorias were investigated under both natural and laboratory conditions. Using Principal Component and Discriminant Function Analyses, the relative shell morphometrics of three feral populations of B. stenochorias were found to vary. Length was shown to adequately represent growth of the shell, although the inclusion of width measurements is more statistically preferable. Two of the feral populations, one in impacted water, were studied weekly for 52 weeks to assess natural population dynamics. Based on the Von Bertalanffy Growth Equation, estimates of growth and longevity were made for this species, with growth highly seasonal. Age is not easily discerned from shell size. Egg laying occurred all year round, with early summer (peak egg lay), mid summer (a second, smaller peak in egg lay), and winter (limited presence of eggs) phases. In toxicity testing, consideration is given to the choice of the test organism based on age and sexual development. Consequently, the sexual development of B. stenochorias relative to shell length was determined with the aid of histological examinations of transverse sections of limpets, of all sizes, collected over one year. Limpets less than 3mm shell length were found to be immature in the development of the oocytes and spermatozoa, and were later chosen for acute toxicity tests. A laboratory diet was developed, for both culturing and maintaining of the limpets during toxicity tests; however, the diet requires optimisation. Under laboratory conditions, growth was linear, and individual fecundity highly variable. Successful methods for the collection of limpets from naturally occurring populations, and their acclimation to the laboratory were developed. Three B. stenochorias populations, representing different hydrological and water quality conditions, were compared to a laboratory population (maintained for three years) in their responses to the textile whole effluent and potassium dichromate. Under acute conditions, variability of mortality between limpet populations and between seasons was consistent with acceptable international standards. However, seasonal differences between feral limpets were apparent, with early summer limpets significantly more susceptible to both potassium dichromate and textile effluent than winter limpets. Although mortality occurred within the effluent at all concentrations, no 96 hour LC₅₀ values were obtained. The chronic toxicity effects of the textile whole effluent were assessed over the entire life cycle of B. stenochorias, based on survival, growth and reproductive effects. Lower concentrations of effluent (# 10%) gave greater variability of responses and toxicity than higher concentrations, with a 43 day LC₅₀ of 3.9% effluent. The No Observed Effect Concentrations for survival (over 43 days) were calculated in consecutive years as 0.1% and 1% effluent. Survival is considered a useful tool for determining toxicity endpoints using B. stenochorias. Limpet growth remained linear in effluent, with an apparent stimulation of growth at the 3-10% effluent concentration, confusing the toxicity and variability assessments. The possible addition of nutrients from the effluent points to either a potential inadequacy of the food quality provided in the chronic assessment, or the presence in the effluent of growth stimulants. Growth was also found to be too variable to allow adequate statistical conclusions about the toxicity of the effluent, although it is suggested that growth may be useful in the assessment of single compounds. Despite large individual variability in fecundity, statistical differences were discernible between effluent concentrations. The application of fecundity of B. stenochorias in hazard assessment therefore warrants further investigation. It was concluded that an assessment of textile whole effluent toxicity to B. stenochorias over an entire life cycle, and an F1 generation, is unnecessary. The development of the bucket/plastic bag method for both acute and chronic toxicity assessment of B. stenochorias was useful. In the final assessment of the usefulness of B. stenochorias as a toxicity indicator, toxicity endpoints were compared with those of the standard laboratory organism Daphnia pulex. Both in acute and chronic toxicity, B. stenochorias was found to be more sensitive. B. stenochorias is therefore considered valuable as a South African freshwater molluscan ecotoxicological indicator, with a place in hazard assessment, although further development and research is necessary before the limpet can be effectively used.
- Full Text:
- Date Issued: 2002
Photophysical studies of Zinc phthalocyanine-silica nanoparticles conjugates
- Authors: Fashina, Adedayo
- Date: 2015
- Subjects: Nanoparticles , Phthalocyanines , Zinc , Silica , Photochemistry , Adsorption
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4537 , http://hdl.handle.net/10962/d1017917
- Description: This thesis reports on the synthesis and characterization of both symmetrical and asymmetrical Zinc phthalocyanine complexes. The complexes contained groups such as carboxylic, amino and alkyne for covalent grafting to the surface of silica nanoparticles. The use of symmetrical and asymmetrical complexes was geared towards comparing the non-specific binding of the symmetrical complexes to the specific binding observed in the asymmetrical complexes. The complexes were also doped within the silica matrix and compared to the surface grafted conjugates. The complexes and the conjugates were well characterized with a variety of techniques. The fluorescence lifetimes of the phthalocyanine complexes containing either terminal carboxylic groups or an alkyne group showed a mono-exponential decay while the amino containing phthalocyanine complexes gave a bi-exponential decay. A similar trend was observed for their respective conjugates. Some of the conjugates of the asymmetrical complexes showed a decrease in fluorescence lifetimes and a corresponding decrease in fluorescence quantum yields. The fluorescence quantum yields for all the symmetrical complexes studied showed either an improvement or retained the luminescence of the grafted phthalocyanine complex. Most of the conjugates showed a faster intersystem crossing time in comparison to the complexes alone. The grafted or doped conjugates containing symmetrical phthalocyanine complexes with carboxyl groups showed improvements both in fluorescence and triplet quantum yields. All the conjugates except two showed an increase in triplet lifetimes when compared to their respective phthalocyanine complexes. Optical nonlinearities of nine of the phthalocyanine complexes were studied and all the complexes showed characteristic reverse saturable absorption behavior. Complex 10 showed the most promising optical limiting behavior. The aggregation and dissolution studies of the conjugates were also carried out in a simulated biological medium and the silicon level detected was noticed to have increased with incubation time.
- Full Text:
- Date Issued: 2015
- Authors: Fashina, Adedayo
- Date: 2015
- Subjects: Nanoparticles , Phthalocyanines , Zinc , Silica , Photochemistry , Adsorption
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4537 , http://hdl.handle.net/10962/d1017917
- Description: This thesis reports on the synthesis and characterization of both symmetrical and asymmetrical Zinc phthalocyanine complexes. The complexes contained groups such as carboxylic, amino and alkyne for covalent grafting to the surface of silica nanoparticles. The use of symmetrical and asymmetrical complexes was geared towards comparing the non-specific binding of the symmetrical complexes to the specific binding observed in the asymmetrical complexes. The complexes were also doped within the silica matrix and compared to the surface grafted conjugates. The complexes and the conjugates were well characterized with a variety of techniques. The fluorescence lifetimes of the phthalocyanine complexes containing either terminal carboxylic groups or an alkyne group showed a mono-exponential decay while the amino containing phthalocyanine complexes gave a bi-exponential decay. A similar trend was observed for their respective conjugates. Some of the conjugates of the asymmetrical complexes showed a decrease in fluorescence lifetimes and a corresponding decrease in fluorescence quantum yields. The fluorescence quantum yields for all the symmetrical complexes studied showed either an improvement or retained the luminescence of the grafted phthalocyanine complex. Most of the conjugates showed a faster intersystem crossing time in comparison to the complexes alone. The grafted or doped conjugates containing symmetrical phthalocyanine complexes with carboxyl groups showed improvements both in fluorescence and triplet quantum yields. All the conjugates except two showed an increase in triplet lifetimes when compared to their respective phthalocyanine complexes. Optical nonlinearities of nine of the phthalocyanine complexes were studied and all the complexes showed characteristic reverse saturable absorption behavior. Complex 10 showed the most promising optical limiting behavior. The aggregation and dissolution studies of the conjugates were also carried out in a simulated biological medium and the silicon level detected was noticed to have increased with incubation time.
- Full Text:
- Date Issued: 2015
A new role for the non-aligned movement in a post-cold war era
- Authors: Chetty, Mahesh
- Date: 2000
- Subjects: Non-Aligned Movement , Nonalignment , Nonalignment -- Developing countries , International police
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2767 , http://hdl.handle.net/10962/d1002977 , Non-Aligned Movement , Nonalignment , Nonalignment -- Developing countries , International police
- Description: With the disappearance of the superpower conflict that characterised the Cold War era, many observers have begun to question whether the Non-Aligned Movement (NAM) has a role to play in the post Cold War era. However the emergence of a number of issues on the international agenda, such as United Nations peacekeeping operations, global environmental issues and an increasing unwillingness on the part of the major economic powers to abide by GATT/WTO rules, have increasingly become of concern to non-aligned states. However whilst the United States has recognised that these issues require leadership in dealing with them, it has not been willing to supply that leadership. It shall therefore be argued that the changing nature of hegemony in world politics has set conditions that allow non-aligned middle powers and institutions greater scope for action and influence. The emergence of these issues has provided a scope for non-aligned middle powers, acting in accordance with their interests to play alternate leadership roles within an expanded scope for institutions, such as organisations, regimes and multilateralism, in addressing the interests of non-aligned states. Firstly in looking at an expanded role for organisations, the United States has increasingly been unwilling to play a leadership role within UN peacekeeping operations. The continuing importance of the neutrality of UN peacekeeping operations has provided a scope for nonaligned middle powers to play a burden-sharing role with the great powers in addressing the concerns of non-aligned states with regard to these operations. Secondly in looking at an expanded scope for regimes, the emergence of a regime in the issue of ozone depletion may provide a foundation to analyse how non-aligned middle powers may play a bridge-building role between North and South in the issue of climate change. Middle powers could therefore play this role in the absence of United States leadership within this issue. Thirdly, the role of the Cairns Group within the Uruguay Round in addressing non-aligned states’ interests of maintaining stable agricultural trade, can be seen as a model of small group multilateralism in bridging the divide between the major powers in issue specific areas.
- Full Text:
- Date Issued: 2000
- Authors: Chetty, Mahesh
- Date: 2000
- Subjects: Non-Aligned Movement , Nonalignment , Nonalignment -- Developing countries , International police
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2767 , http://hdl.handle.net/10962/d1002977 , Non-Aligned Movement , Nonalignment , Nonalignment -- Developing countries , International police
- Description: With the disappearance of the superpower conflict that characterised the Cold War era, many observers have begun to question whether the Non-Aligned Movement (NAM) has a role to play in the post Cold War era. However the emergence of a number of issues on the international agenda, such as United Nations peacekeeping operations, global environmental issues and an increasing unwillingness on the part of the major economic powers to abide by GATT/WTO rules, have increasingly become of concern to non-aligned states. However whilst the United States has recognised that these issues require leadership in dealing with them, it has not been willing to supply that leadership. It shall therefore be argued that the changing nature of hegemony in world politics has set conditions that allow non-aligned middle powers and institutions greater scope for action and influence. The emergence of these issues has provided a scope for non-aligned middle powers, acting in accordance with their interests to play alternate leadership roles within an expanded scope for institutions, such as organisations, regimes and multilateralism, in addressing the interests of non-aligned states. Firstly in looking at an expanded role for organisations, the United States has increasingly been unwilling to play a leadership role within UN peacekeeping operations. The continuing importance of the neutrality of UN peacekeeping operations has provided a scope for nonaligned middle powers to play a burden-sharing role with the great powers in addressing the concerns of non-aligned states with regard to these operations. Secondly in looking at an expanded scope for regimes, the emergence of a regime in the issue of ozone depletion may provide a foundation to analyse how non-aligned middle powers may play a bridge-building role between North and South in the issue of climate change. Middle powers could therefore play this role in the absence of United States leadership within this issue. Thirdly, the role of the Cairns Group within the Uruguay Round in addressing non-aligned states’ interests of maintaining stable agricultural trade, can be seen as a model of small group multilateralism in bridging the divide between the major powers in issue specific areas.
- Full Text:
- Date Issued: 2000
Classification of the difficulty in accelerating problems using GPUs
- Authors: Tristram, Uvedale Roy
- Date: 2014
- Subjects: Graphics processing units , Computer algorithms , Computer programming , Problem solving -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4699 , http://hdl.handle.net/10962/d1012978
- Description: Scientists continually require additional processing power, as this enables them to compute larger problem sizes, use more complex models and algorithms, and solve problems previously thought computationally impractical. General-purpose computation on graphics processing units (GPGPU) can help in this regard, as there is great potential in using graphics processors to accelerate many scientific models and algorithms. However, some problems are considerably harder to accelerate than others, and it may be challenging for those new to GPGPU to ascertain the difficulty of accelerating a particular problem or seek appropriate optimisation guidance. Through what was learned in the acceleration of a hydrological uncertainty ensemble model, large numbers of k-difference string comparisons, and a radix sort, problem attributes have been identified that can assist in the evaluation of the difficulty in accelerating a problem using GPUs. The identified attributes are inherent parallelism, branch divergence, problem size, required computational parallelism, memory access pattern regularity, data transfer overhead, and thread cooperation. Using these attributes as difficulty indicators, an initial problem difficulty classification framework has been created that aids in GPU acceleration difficulty evaluation. This framework further facilitates directed guidance on suggested optimisations and required knowledge based on problem classification, which has been demonstrated for the aforementioned accelerated problems. It is anticipated that this framework, or a derivative thereof, will prove to be a useful resource for new or novice GPGPU developers in the evaluation of potential problems for GPU acceleration.
- Full Text:
- Date Issued: 2014
- Authors: Tristram, Uvedale Roy
- Date: 2014
- Subjects: Graphics processing units , Computer algorithms , Computer programming , Problem solving -- Data processing
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4699 , http://hdl.handle.net/10962/d1012978
- Description: Scientists continually require additional processing power, as this enables them to compute larger problem sizes, use more complex models and algorithms, and solve problems previously thought computationally impractical. General-purpose computation on graphics processing units (GPGPU) can help in this regard, as there is great potential in using graphics processors to accelerate many scientific models and algorithms. However, some problems are considerably harder to accelerate than others, and it may be challenging for those new to GPGPU to ascertain the difficulty of accelerating a particular problem or seek appropriate optimisation guidance. Through what was learned in the acceleration of a hydrological uncertainty ensemble model, large numbers of k-difference string comparisons, and a radix sort, problem attributes have been identified that can assist in the evaluation of the difficulty in accelerating a problem using GPUs. The identified attributes are inherent parallelism, branch divergence, problem size, required computational parallelism, memory access pattern regularity, data transfer overhead, and thread cooperation. Using these attributes as difficulty indicators, an initial problem difficulty classification framework has been created that aids in GPU acceleration difficulty evaluation. This framework further facilitates directed guidance on suggested optimisations and required knowledge based on problem classification, which has been demonstrated for the aforementioned accelerated problems. It is anticipated that this framework, or a derivative thereof, will prove to be a useful resource for new or novice GPGPU developers in the evaluation of potential problems for GPU acceleration.
- Full Text:
- Date Issued: 2014
I won’t be long
- Mhlambi, Ntombi Kayise Millicent
- Authors: Mhlambi, Ntombi Kayise Millicent
- Date: 2018
- Subjects: Creative writing (Higher education) -- South Africa , South African fiction (English) -- 21st century , South African poetry (English) -- 21st century , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63603 , vital:28446
- Description: My thesis is a weave of short stories, flash fiction and vignettes of prose-poetry. It uses lyrical, scenic and explorative modes to explore the stories of women, past, present and future, from all walks of life. These women, young and old, struggle to find their way within a ‘world’ characterised as Salithambo (the pink castle) whose structures and survival preys on their bodies. The stories explore the themes of girlhood and maturation, violence (specifically against women), animality, scatology, time, gender roles and expectations, and their rejection. I draw inspiration, stylistically, from Irenosen Okojie’s depiction of beauty and terror in the same sentence; Selah Saterstrom’s fragmented plot and directorial stroke; Taban Lo Liyong & Amos Tutuola’s avant-gardism and amplification of language; Adania Shibli’s sensorial and spare prose, Lyudmila Petrushevskaya, Lily Hoang & Carol Oates’ normalized magic spell, Athena Villaverde & Espido Freire’s imaginative overload of childhood; Shelley Jackson & Chevisa Woods’ construction of body parts as bearing texts or as texts themselves.
- Full Text:
- Date Issued: 2018
- Authors: Mhlambi, Ntombi Kayise Millicent
- Date: 2018
- Subjects: Creative writing (Higher education) -- South Africa , South African fiction (English) -- 21st century , South African poetry (English) -- 21st century , Short stories, South African (English) -- 21st century
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: http://hdl.handle.net/10962/63603 , vital:28446
- Description: My thesis is a weave of short stories, flash fiction and vignettes of prose-poetry. It uses lyrical, scenic and explorative modes to explore the stories of women, past, present and future, from all walks of life. These women, young and old, struggle to find their way within a ‘world’ characterised as Salithambo (the pink castle) whose structures and survival preys on their bodies. The stories explore the themes of girlhood and maturation, violence (specifically against women), animality, scatology, time, gender roles and expectations, and their rejection. I draw inspiration, stylistically, from Irenosen Okojie’s depiction of beauty and terror in the same sentence; Selah Saterstrom’s fragmented plot and directorial stroke; Taban Lo Liyong & Amos Tutuola’s avant-gardism and amplification of language; Adania Shibli’s sensorial and spare prose, Lyudmila Petrushevskaya, Lily Hoang & Carol Oates’ normalized magic spell, Athena Villaverde & Espido Freire’s imaginative overload of childhood; Shelley Jackson & Chevisa Woods’ construction of body parts as bearing texts or as texts themselves.
- Full Text:
- Date Issued: 2018
Adolescent pregnancy: a community engaged participatory approach to design and implement an educational intervention
- Authors: Siruma, Amanda Tatenda
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54656 , vital:26597
- Description: Millennium Development Goal (MDG) 5 focuses on improving maternal health, due to global acknowledgment that no woman should have to die as a result of complications during pregnancy and childbirth. Adolescents have an increased risk of maternal death compared with older women. Adolescent pregnancy also poses a threat to the empowerment of young girls by mitigating their physical, educational, social, and economic development. In this context, maternal health promotion strategies which inclusively target adolescents are crucial, not only in improving maternal health outcomes, but also in optimising the overall transition of adolescent girls to adulthood. This study was a first time collaborative partnership of the Faculty of Pharmacy and Community Engagement Office of Rhodes University with the Angus Gillis Foundation (a non-profit community development organisation), and community participants of Glenmore and Ndwayana, two rural communities in the Eastern Cape. The aim of this study was to identify the maternal health issue of most concern to community participants and to design and implement an appropriate educational intervention for a suitable target group. During the baseline phase of this study, ten focus group discussions (FGDs) were conducted with 76 community stakeholders. Semi-structured interviews (SSIs) were conducted with two Sisters-in-Charge from each Primary Health Care (PHC) facility in the study setting. Data on the stock status of World Health Organization (WHO) identified lifesaving priority medicines for women’s health was also collected at both PHCs. Thereafter, pre- and posteducational interventions SSIs with female adolescent participants were conducted. The educational intervention was followed up with the development of a booklet on reproductive health. FGD participants identified adolescent pregnancy as the maternal health issue of most concern. They also highlighted challenges in service delivery of ambulance services for expectant mothers in urgent need of transportation to a referral hospital. A majority of preintervention SSI participants indicated coercion from both younger and older men as a factor influencing early sexual debut amongst adolescent girls in their communities. Despite availability in the PHCs, challenges in accessing contraceptives were highlighted by the participants. Additionally, a number of sexually active adolescent girls defaulted on their next allocated visit to the PHC due to myths regarding use of oral and injectable contraceptives. During the educational intervention sessions, participants recognised knowledge gaps regarding reproductive health issues and the influence of peer pressure as constraining factors in preventing adolescent pregnancy. During the post-intervention phase, participants highlighted that the educational intervention of this study had provided a forum to discuss ways of preventing adolescent pregnancy. The educational booklet developed is intended to serve as a resource tool of the educational programme on prevention of adolescent pregnancy, which is expected to be incorporated into the Angus Gillis Foundation’s existing ‘Positive Health’ Programme. The results of this study show that community-based participatory research facilitated the identification of the maternal health issue of most concern to these communities. Working synergistically with key stakeholders in designing and implementing an educational intervention for preventing adolescent pregnancy provides a good foundation for future up scaling and sustainability of this educational programme.
- Full Text:
- Date Issued: 2014
- Authors: Siruma, Amanda Tatenda
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MPharm
- Identifier: http://hdl.handle.net/10962/54656 , vital:26597
- Description: Millennium Development Goal (MDG) 5 focuses on improving maternal health, due to global acknowledgment that no woman should have to die as a result of complications during pregnancy and childbirth. Adolescents have an increased risk of maternal death compared with older women. Adolescent pregnancy also poses a threat to the empowerment of young girls by mitigating their physical, educational, social, and economic development. In this context, maternal health promotion strategies which inclusively target adolescents are crucial, not only in improving maternal health outcomes, but also in optimising the overall transition of adolescent girls to adulthood. This study was a first time collaborative partnership of the Faculty of Pharmacy and Community Engagement Office of Rhodes University with the Angus Gillis Foundation (a non-profit community development organisation), and community participants of Glenmore and Ndwayana, two rural communities in the Eastern Cape. The aim of this study was to identify the maternal health issue of most concern to community participants and to design and implement an appropriate educational intervention for a suitable target group. During the baseline phase of this study, ten focus group discussions (FGDs) were conducted with 76 community stakeholders. Semi-structured interviews (SSIs) were conducted with two Sisters-in-Charge from each Primary Health Care (PHC) facility in the study setting. Data on the stock status of World Health Organization (WHO) identified lifesaving priority medicines for women’s health was also collected at both PHCs. Thereafter, pre- and posteducational interventions SSIs with female adolescent participants were conducted. The educational intervention was followed up with the development of a booklet on reproductive health. FGD participants identified adolescent pregnancy as the maternal health issue of most concern. They also highlighted challenges in service delivery of ambulance services for expectant mothers in urgent need of transportation to a referral hospital. A majority of preintervention SSI participants indicated coercion from both younger and older men as a factor influencing early sexual debut amongst adolescent girls in their communities. Despite availability in the PHCs, challenges in accessing contraceptives were highlighted by the participants. Additionally, a number of sexually active adolescent girls defaulted on their next allocated visit to the PHC due to myths regarding use of oral and injectable contraceptives. During the educational intervention sessions, participants recognised knowledge gaps regarding reproductive health issues and the influence of peer pressure as constraining factors in preventing adolescent pregnancy. During the post-intervention phase, participants highlighted that the educational intervention of this study had provided a forum to discuss ways of preventing adolescent pregnancy. The educational booklet developed is intended to serve as a resource tool of the educational programme on prevention of adolescent pregnancy, which is expected to be incorporated into the Angus Gillis Foundation’s existing ‘Positive Health’ Programme. The results of this study show that community-based participatory research facilitated the identification of the maternal health issue of most concern to these communities. Working synergistically with key stakeholders in designing and implementing an educational intervention for preventing adolescent pregnancy provides a good foundation for future up scaling and sustainability of this educational programme.
- Full Text:
- Date Issued: 2014
Gold metallogeny of Australia
- Authors: Rankine, Graham M
- Date: 1987
- Subjects: Gold ores -- Geology -- Australia , Gold mines and mining -- Australia , Gold -- Metallurgy -- Australia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4928 , http://hdl.handle.net/10962/d1004676
- Description: The gold metallogeny of Australia is predominantly confined to the Archaean and Palaeozoic Provinces. The Archaean gold occurrences are predominantly hosted in ultramafic-mafic dominated greenstone belts, with less associated tofelsic-volcanic and sedimentary sequences. Most gold occurrences are confined to shear zones or faults, and adjacent discoveries of economic laterite-hosted deposits, host rocks. Recent are presently under investigation and will supply a significant proportion of production in the future. The Proterozoic gold deposits of Australia , are confined to geosyncinal sequences, commonly turbidites (eg: Telfer), with other hydrothermal deposits associated directly to granites. An important feature of the North Australian Craton deposits, is the spatial association of most deposits to granite bodies, although a genetic link has not been established conclusively. The Roxby Downs deposit in South Australia is a unique occurrence of gold in association to copper, uranium and R.E.E. This deposit is tentatively related to intraplate alkaline-magmatism, with further work necessary. The most significant recent discovery of gold mineralization in Australia is in the Drummond Basin in Queensland. This epithermal is tentatively related to mineralization within the Georgetown Inlier. The latter mineralization is Permo-Carboniferous, in a Proterozoic (and possibly Archaean) sequence of schists. It is tentatively suggested that all the gold mineralization in northern Queensland may be related to single tectonic event, a feature which requires further study . Other mineralization in the Phanerozoic includes the turbidite-hosted metamorphogenic deposits of Victoria, the rift related deposits in New South Wales and magmatic related deposits in Queensland. The gold deposits in Australia may in the future be classified in a tectonogeological framework, similiar to the layout of this dissertation, particularly once further data becomes available on recent discoveries.
- Full Text:
- Date Issued: 1987
- Authors: Rankine, Graham M
- Date: 1987
- Subjects: Gold ores -- Geology -- Australia , Gold mines and mining -- Australia , Gold -- Metallurgy -- Australia
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4928 , http://hdl.handle.net/10962/d1004676
- Description: The gold metallogeny of Australia is predominantly confined to the Archaean and Palaeozoic Provinces. The Archaean gold occurrences are predominantly hosted in ultramafic-mafic dominated greenstone belts, with less associated tofelsic-volcanic and sedimentary sequences. Most gold occurrences are confined to shear zones or faults, and adjacent discoveries of economic laterite-hosted deposits, host rocks. Recent are presently under investigation and will supply a significant proportion of production in the future. The Proterozoic gold deposits of Australia , are confined to geosyncinal sequences, commonly turbidites (eg: Telfer), with other hydrothermal deposits associated directly to granites. An important feature of the North Australian Craton deposits, is the spatial association of most deposits to granite bodies, although a genetic link has not been established conclusively. The Roxby Downs deposit in South Australia is a unique occurrence of gold in association to copper, uranium and R.E.E. This deposit is tentatively related to intraplate alkaline-magmatism, with further work necessary. The most significant recent discovery of gold mineralization in Australia is in the Drummond Basin in Queensland. This epithermal is tentatively related to mineralization within the Georgetown Inlier. The latter mineralization is Permo-Carboniferous, in a Proterozoic (and possibly Archaean) sequence of schists. It is tentatively suggested that all the gold mineralization in northern Queensland may be related to single tectonic event, a feature which requires further study . Other mineralization in the Phanerozoic includes the turbidite-hosted metamorphogenic deposits of Victoria, the rift related deposits in New South Wales and magmatic related deposits in Queensland. The gold deposits in Australia may in the future be classified in a tectonogeological framework, similiar to the layout of this dissertation, particularly once further data becomes available on recent discoveries.
- Full Text:
- Date Issued: 1987
Financial integration in East Africa: evidence from interest rate pass-through analysis
- Authors: Bholla, Zohaib Salim
- Date: 2011
- Subjects: East African Community -- Economic integration East African Community -- Economic conditions -- 21st century Interest rates -- Africa, East Interest rates -- Econometric models -- Africa, East Interest rates -- Effect of inflation on -- Africa, East Banks and banking -- Africa, East
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1044 , http://hdl.handle.net/10962/d1006131
- Description: The successful launch of the European Monetary Union (EMU) raised an already ever growing interest in the economics of monetary integration and the formation of monetary unions around the world. Following the EMU experience, countries have considered forming a monetary union amongst themselves. The East African Community (EAC), comprising the three original member countries Kenya, Tanzania and Uganda and now including Burundi and Rwanda, is an example of such a group of countries that seek to form a monetary union. This study aims to identify the current level of financial integration amongst the East African countries. In order to do so the study examines whether the pass-through of monetary policy in the five countries has become similar over time. This is to provide an indication of the extent to which the nominal convergence criteria amongst the member countries have been met. The results of the study provide an indication of whether the formation of a monetary union in East Africa is possible. The empirical analysis used in this study included stationarity tests, four tests of co integration and an asymmetric error correction model to investigate whether the pass-through of monetary policy transmission in the five countries has become more similar over the ten year sample period from 1999 to 2008. The analysis uses three interest rates and 6-year rolling windows to identify the extent of macroeconomic convergence that prevails within the EAC, and consequently whether the formation of a monetary union is possible. The results suggest that the magnitude of the convergence amongst the countries remain low and there are significant rigidities in the deposit and lending rates over time, however the passthrough has improved with respect to the lending rate but not the deposit rate. The overall conclusion of the study suggests that an EAC wide monetary union is currently not possible based on the evidence provided from the pass-through analysis.
- Full Text:
- Date Issued: 2011
- Authors: Bholla, Zohaib Salim
- Date: 2011
- Subjects: East African Community -- Economic integration East African Community -- Economic conditions -- 21st century Interest rates -- Africa, East Interest rates -- Econometric models -- Africa, East Interest rates -- Effect of inflation on -- Africa, East Banks and banking -- Africa, East
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1044 , http://hdl.handle.net/10962/d1006131
- Description: The successful launch of the European Monetary Union (EMU) raised an already ever growing interest in the economics of monetary integration and the formation of monetary unions around the world. Following the EMU experience, countries have considered forming a monetary union amongst themselves. The East African Community (EAC), comprising the three original member countries Kenya, Tanzania and Uganda and now including Burundi and Rwanda, is an example of such a group of countries that seek to form a monetary union. This study aims to identify the current level of financial integration amongst the East African countries. In order to do so the study examines whether the pass-through of monetary policy in the five countries has become similar over time. This is to provide an indication of the extent to which the nominal convergence criteria amongst the member countries have been met. The results of the study provide an indication of whether the formation of a monetary union in East Africa is possible. The empirical analysis used in this study included stationarity tests, four tests of co integration and an asymmetric error correction model to investigate whether the pass-through of monetary policy transmission in the five countries has become more similar over the ten year sample period from 1999 to 2008. The analysis uses three interest rates and 6-year rolling windows to identify the extent of macroeconomic convergence that prevails within the EAC, and consequently whether the formation of a monetary union is possible. The results suggest that the magnitude of the convergence amongst the countries remain low and there are significant rigidities in the deposit and lending rates over time, however the passthrough has improved with respect to the lending rate but not the deposit rate. The overall conclusion of the study suggests that an EAC wide monetary union is currently not possible based on the evidence provided from the pass-through analysis.
- Full Text:
- Date Issued: 2011
An investigation into how grade 10 learners make meaning during the teaching and learning of the topic on nutrition in Life Science: a case study
- Mwiikeni, Helena Twiihaleni, Shimwafeni-Mwiikeni, Helena Twiihaleni
- Authors: Mwiikeni, Helena Twiihaleni , Shimwafeni-Mwiikeni, Helena Twiihaleni
- Date: 2013
- Subjects: Nutrition -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Environmental sciences -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Experiential learning -- Namibia -- Oshana -- Case studies Education, Secondary -- Namibia -- Oshana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1403 , http://hdl.handle.net/10962/d1001876
- Description: The integration of learners’ prior everyday knowledge and experiences during teaching and learning is a pre-requisite in the Namibian curriculum. The curriculum states that if learners are taught in a way which builds on what they already know and they relate new knowledge to the reality around them, their learning in school can be made more meaningful. Thus, learners’ meaning making in the topic on nutrition was researched to find out whether elicitation and integration of learners’ prior everyday knowledge and experience in the nutrition topic enhanced or constrained their learning. This study was conducted with my grade10 learners at the school where I am currently teaching. The school is located in a rural area in Oshana region in Northern Namibia. This study is situated within an interpretive paradigm. Within the interpretive paradigm a qualitative case study approach was adopted. I considered this methodological orientation appropriate in this study as it allowed me to use the following methods: document analysis, brainstorming and discussion, semi-structured interviews and a focus group interview, practical activities with worksheets and observation and reflection. Multiple methods to gather data were used for triangulation and validation purposes. For data analysis purposes, the data sets were colour coded to derive themes and analytical statements. Ethical consideration was also taken seriously in this study. The findings from this study revealed that integration of learners’ prior everyday knowledge and experience enabled learners to understand science better particularly in the topic of nutrition. The study also revealed that learners possess a lot of prior everyday knowledge and experience about food they eat in their homes. However, data from the community members revealed that there are some contradictions between learners’ prior everyday knowledge and the science content of the topic. Nonetheless, engaging learners in practical activities in the testing of food (local and conventional western type foods) helped them to make meaning of the content learned. I therefore, recommend that learners’ prior everyday knowledge and experiences should be incorporated during teaching and learning of the topic on nutrition. The study also recommends that the Department of Education should ensure that teachers get the necessary support and training on how to integrate learners’ prior everyday knowledge and experiences.
- Full Text:
- Date Issued: 2013
- Authors: Mwiikeni, Helena Twiihaleni , Shimwafeni-Mwiikeni, Helena Twiihaleni
- Date: 2013
- Subjects: Nutrition -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Environmental sciences -- Study and teaching (Secondary) -- Namibia -- Oshana -- Case studies Experiential learning -- Namibia -- Oshana -- Case studies Education, Secondary -- Namibia -- Oshana
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1403 , http://hdl.handle.net/10962/d1001876
- Description: The integration of learners’ prior everyday knowledge and experiences during teaching and learning is a pre-requisite in the Namibian curriculum. The curriculum states that if learners are taught in a way which builds on what they already know and they relate new knowledge to the reality around them, their learning in school can be made more meaningful. Thus, learners’ meaning making in the topic on nutrition was researched to find out whether elicitation and integration of learners’ prior everyday knowledge and experience in the nutrition topic enhanced or constrained their learning. This study was conducted with my grade10 learners at the school where I am currently teaching. The school is located in a rural area in Oshana region in Northern Namibia. This study is situated within an interpretive paradigm. Within the interpretive paradigm a qualitative case study approach was adopted. I considered this methodological orientation appropriate in this study as it allowed me to use the following methods: document analysis, brainstorming and discussion, semi-structured interviews and a focus group interview, practical activities with worksheets and observation and reflection. Multiple methods to gather data were used for triangulation and validation purposes. For data analysis purposes, the data sets were colour coded to derive themes and analytical statements. Ethical consideration was also taken seriously in this study. The findings from this study revealed that integration of learners’ prior everyday knowledge and experience enabled learners to understand science better particularly in the topic of nutrition. The study also revealed that learners possess a lot of prior everyday knowledge and experience about food they eat in their homes. However, data from the community members revealed that there are some contradictions between learners’ prior everyday knowledge and the science content of the topic. Nonetheless, engaging learners in practical activities in the testing of food (local and conventional western type foods) helped them to make meaning of the content learned. I therefore, recommend that learners’ prior everyday knowledge and experiences should be incorporated during teaching and learning of the topic on nutrition. The study also recommends that the Department of Education should ensure that teachers get the necessary support and training on how to integrate learners’ prior everyday knowledge and experiences.
- Full Text:
- Date Issued: 2013
A comparison of the views of modern scholars on the origin, date and importance for O.T. study of the Dead Sea Scrolls
- Authors: Sheriffs, Robert J A
- Date: 1954
- Subjects: Dead Sea scrolls
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1273 , http://hdl.handle.net/10962/d1013179
- Description: In the early part of 1948 an announcement was made concerning the discovery of some ancient manuscripts in Palestine; to this discovery sober and distinguished scholars applied adjectives like 'sensational' and 'phenomenal' - words that not commonly applied to the discovery of manuscripts in the world of scholarship.
- Full Text:
- Date Issued: 1954
- Authors: Sheriffs, Robert J A
- Date: 1954
- Subjects: Dead Sea scrolls
- Language: English
- Type: Thesis , Bachelor , BDiv
- Identifier: vital:1273 , http://hdl.handle.net/10962/d1013179
- Description: In the early part of 1948 an announcement was made concerning the discovery of some ancient manuscripts in Palestine; to this discovery sober and distinguished scholars applied adjectives like 'sensational' and 'phenomenal' - words that not commonly applied to the discovery of manuscripts in the world of scholarship.
- Full Text:
- Date Issued: 1954
A strategy for promoting computer literacy in staff and students of a teacher training institution : a case study
- Authors: Keep, Joan Diane
- Date: 1992
- Subjects: Computer literacy Computer-assisted instruction Teachers -- Training of -- Data processing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1773 , http://hdl.handle.net/10962/d1003658
- Description: A case study carried out at Edgewood College of Education (Natal) attempted to demonstrate how in-house training could provide staff with the necessary computer literacy skills to integrate computer technology into lecturing and teaching programmes. The duration of the project was six months and during this time a group of thirty academic staff members were exposed to computer technology via practical experience, lectures and demonstrations. The results gleaned from the project show that most of the staff involved in the project developed sufficient computer skills to be of benefit in their professional and personal tasks. In addition the recognition of the value of word processing and desk top publishing led to the staff encouraging students to use these software packages in the preparation of coursework. Consequently the use of the computer resources increased noticeably in the six month period. One of the goals of the study was to show how staff, once computer literate, would make use of generic software to integrate computer technology into their lecturing programmes. This did not happen and the reasons for this failure are discussed.
- Full Text:
- Date Issued: 1992
- Authors: Keep, Joan Diane
- Date: 1992
- Subjects: Computer literacy Computer-assisted instruction Teachers -- Training of -- Data processing
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1773 , http://hdl.handle.net/10962/d1003658
- Description: A case study carried out at Edgewood College of Education (Natal) attempted to demonstrate how in-house training could provide staff with the necessary computer literacy skills to integrate computer technology into lecturing and teaching programmes. The duration of the project was six months and during this time a group of thirty academic staff members were exposed to computer technology via practical experience, lectures and demonstrations. The results gleaned from the project show that most of the staff involved in the project developed sufficient computer skills to be of benefit in their professional and personal tasks. In addition the recognition of the value of word processing and desk top publishing led to the staff encouraging students to use these software packages in the preparation of coursework. Consequently the use of the computer resources increased noticeably in the six month period. One of the goals of the study was to show how staff, once computer literate, would make use of generic software to integrate computer technology into their lecturing programmes. This did not happen and the reasons for this failure are discussed.
- Full Text:
- Date Issued: 1992
Mesopredator release and the effectiveness of camera traps for estimating mammal abundances in the Eastern Cape, South Africa
- Authors: Taylor, Jonathan Michael
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3587 , vital:20527
- Description: Remotely operated cameras (camera traps) have become an indispensable tool for many ecologists, particularly those studying rare and elusive animals. A plethora of camera trap makes and models are now commercially available, yet the effects of their varying design features on the quality and quantity of data recorded remains principally unknown. Better understanding of differing camera trap designs is needed before adequate management policies can be implemented, especially when the aim is to protect vulnerable and endangered species such as many carnivores. Habitat loss and human conflict has prompted worldwide declines of apex predator populations. Following this, many smaller predators have undergone population ‘explosions’ due to the lack of top-down forcing, a phenomenon known as mesopredator release. Land use changes in the Eastern Cape of South Africa have caused extensive degradation and fragmentation of the Subtropical Thicket Biome. In addition, coupled with anthropogenic persecution, apex predators including lions (Panthera leo), leopards (P. pardus), and brown hyaenas (Hyaena brunnea) have been extirpated from large areas of their historic range. Removal of these apex predators may provide opportunity for mesopredators, such as black-backed jackals (Canis mesomelas) and caracals (Caracal caracal), to be released from top-down forcing and possibly initiate trophic cascade effects. Therefore, using randomly distributed camera traps, my study aimed to explore the quality and quantity of data collected by different camera trap designs, and to investigate the mesopredator release hypothesis in the Eastern Cape of South Africa. A total of 2,989 trap nights was used to compare camera trap designs. Camera traps with narrow detection zones and fast trigger speeds (≤ 0.25 seconds) recorded a higher diversity of carnivores, but there was no significant difference in the relative abundances of carnivore species recorded by different camera trap models. A total of 19,659 trap nights was used to assess mesopredator relative abundance, occupancy, distribution and daily activity patterns at one site with, and one site without, apex predators. Consistent with the mesopredator release hypothesis, black-backed jackal relative abundance was significantly higher in the absence of apex predators, and this was supported by occupancy analyses. Further, black-backed jackal distribution was significantly concentrated in areas where apex predator activity was low, possibly indicating spatial avoidance. There was no significant difference in caracal relative abundance, occupancy, distribution, or daily activity between sites. These results provide the first indication of mesopredator release of blackbacked jackals in the Eastern Cape. The implications of black-backed jackal release including prey population structure, local extinctions, altered seed dispersal and disease dynamics are discussed.
- Full Text:
- Date Issued: 2016
- Authors: Taylor, Jonathan Michael
- Date: 2016
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/3587 , vital:20527
- Description: Remotely operated cameras (camera traps) have become an indispensable tool for many ecologists, particularly those studying rare and elusive animals. A plethora of camera trap makes and models are now commercially available, yet the effects of their varying design features on the quality and quantity of data recorded remains principally unknown. Better understanding of differing camera trap designs is needed before adequate management policies can be implemented, especially when the aim is to protect vulnerable and endangered species such as many carnivores. Habitat loss and human conflict has prompted worldwide declines of apex predator populations. Following this, many smaller predators have undergone population ‘explosions’ due to the lack of top-down forcing, a phenomenon known as mesopredator release. Land use changes in the Eastern Cape of South Africa have caused extensive degradation and fragmentation of the Subtropical Thicket Biome. In addition, coupled with anthropogenic persecution, apex predators including lions (Panthera leo), leopards (P. pardus), and brown hyaenas (Hyaena brunnea) have been extirpated from large areas of their historic range. Removal of these apex predators may provide opportunity for mesopredators, such as black-backed jackals (Canis mesomelas) and caracals (Caracal caracal), to be released from top-down forcing and possibly initiate trophic cascade effects. Therefore, using randomly distributed camera traps, my study aimed to explore the quality and quantity of data collected by different camera trap designs, and to investigate the mesopredator release hypothesis in the Eastern Cape of South Africa. A total of 2,989 trap nights was used to compare camera trap designs. Camera traps with narrow detection zones and fast trigger speeds (≤ 0.25 seconds) recorded a higher diversity of carnivores, but there was no significant difference in the relative abundances of carnivore species recorded by different camera trap models. A total of 19,659 trap nights was used to assess mesopredator relative abundance, occupancy, distribution and daily activity patterns at one site with, and one site without, apex predators. Consistent with the mesopredator release hypothesis, black-backed jackal relative abundance was significantly higher in the absence of apex predators, and this was supported by occupancy analyses. Further, black-backed jackal distribution was significantly concentrated in areas where apex predator activity was low, possibly indicating spatial avoidance. There was no significant difference in caracal relative abundance, occupancy, distribution, or daily activity between sites. These results provide the first indication of mesopredator release of blackbacked jackals in the Eastern Cape. The implications of black-backed jackal release including prey population structure, local extinctions, altered seed dispersal and disease dynamics are discussed.
- Full Text:
- Date Issued: 2016
Aspects of fuzzy spaces with special reference to cardinality, dimension, and order-homomorphisms
- Authors: Lubczonok, Pawel
- Date: 1992
- Subjects: Fuzzy sets Topological spaces
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5399 , http://hdl.handle.net/10962/d1005213
- Description: Aspects of fuzzy vector spaces and fuzzy groups are investigated, including linear independence, basis, dimension, group order, finitely generated groups and cyclic groups. It was necessary to consider cardinality of fuzzy sets and related issues, which included a question of ways in which to define functions between fuzzy sets. Among the results proved, are the additivity property of dimension for fuzzy vector spaces, Lagrange's Theorem for fuzzy groups ( the existing version of this theorem does not take fuzziness into account at all), a compactness property of finitely generated fuzzy groups and an extension of an earlier result on the order-homomorphisms. An open question is posed with regard to the existence of a basis for an arbitrary fuzzy vector space.
- Full Text:
- Date Issued: 1992
- Authors: Lubczonok, Pawel
- Date: 1992
- Subjects: Fuzzy sets Topological spaces
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5399 , http://hdl.handle.net/10962/d1005213
- Description: Aspects of fuzzy vector spaces and fuzzy groups are investigated, including linear independence, basis, dimension, group order, finitely generated groups and cyclic groups. It was necessary to consider cardinality of fuzzy sets and related issues, which included a question of ways in which to define functions between fuzzy sets. Among the results proved, are the additivity property of dimension for fuzzy vector spaces, Lagrange's Theorem for fuzzy groups ( the existing version of this theorem does not take fuzziness into account at all), a compactness property of finitely generated fuzzy groups and an extension of an earlier result on the order-homomorphisms. An open question is posed with regard to the existence of a basis for an arbitrary fuzzy vector space.
- Full Text:
- Date Issued: 1992
A comparative kinetic study of the reaction between chromium nitrate solutions and the carboxyl groups of acetate and collage
- Authors: Russell, Allan Edward
- Date: 1962
- Subjects: Chemical kinetics , Chromium , Spectrophotometry , Electrophoresis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4493 , http://hdl.handle.net/10962/d1013101
- Description: The kinetics of the coordination reaction between the carboxyl group of the acetate radical and the trivalent chromium ion has been examined by independent methods at a temperature selected to yield reasonably accurate rate data. The study has been extended to an examination of the rate of chromium "fixation" by the carboxyl groups of hide collagen in a series of miniature tannages carried out under similar conditions for comparative purposes. The effect of olation of the chromium ions in solution on the kinetics of t he coordination reaction has also been examined. The rate of coordination of the acetate radical was followed by solvent extraction and spectrophotometric techniques over a range of concentration and pH levels. The rate data revealed a reaction having typical mass-action characteristics, the rate of reaction depending on the concentration levels of the chromium ion and the ionised acetate radical. An attempt made to distinguish a differential reaction rate in the case of a parallel reaction series using boiled and aged chromium nitrate reactant solutions, failed to reveal any significant differences between the series. The reactant solutions gave absorption spectra characteristic of the trivalent chromium ion with maxima in the 420 mµ and 570 mµ wavelength regions. The changes in optical density occurring in the vicinity of the maxima were followed spectrophotometrically, the height of the 570 mµ being found to increase during the course of reaction, while the height of the 420 mµ peak decreased. The variation in optical density at the 570 mµ peak was found to be directly related to the increase in concentration of the product complex in solution in accordance with the Baer-Bougher law, while the decrease in the height of the 420 mµ peak was related to the properties of unolated OH groups associated with the chromium complex as governed by pH and olation changes during the course of reaction. Boiled and aged chromium nitrate solutions gave reactant solutions having initial optical densities greater than those of the correspending fresh reactant solutions at the 570 mµ peak, and less than those of the fresh solutions at the 420 mµ peak. During the course of reaction, however, the two series converged to the same values. The equilibrium reaction solutions were subjected to paper electrophoretic study which indicated that all tho chromium was present in the form of cationic species. This finding was in accordance with stoicheiometric indications in the solvent extraction studies where coordination in a l : 1 ratio was reflected, giving rise to positively charged complex ions only. Making due allowance for band spreading the numbers of species predicted from the kinetic studies correspond with the electrophoretic patterns found. Application of the classical second order kinetic expression to the solvent extraction rate data, yielded plots having two distinctly linear sections, apparently indicating consecutive second order processes occurring in solution, contrary to the findings of previous workers who assign a first order mechanism to the reaction. This finding was consistent with the view that in the case of both the fresh and aged series, reaction consisted of successive coordination of an acetate radical to each chromium atom of a diol complex. Second order rate "constants" were calculated for each step and their dependency on pH level demonstrated. The findings of Hamm et al that these were first order reactions independent of acetate co'ncentration are believed to be due to their use of a large excess of acetate in their experiments. The kinetic study was further extended to an examination of the rate of "fixation"of trivalent chromium by the carboxyl groups of hide collagen under comparable conditions in a series of miniaturv tanning experiments in which the tannage substrate was provided in each of two physical forms:- (a) As hide powder where surface development was large, and (b) as prepared pelt pieces in which the fibrous weave pattern was retained. In view of the heterogeneity of the tannage systems, remarkable similarity was observed in the reaction course when compared with that of the acetate coordination studies, particularly in the case of the hide powder tannages. The dependency of the tannage rate data upon concentration and pH conditions was also found to be the same as in the case of the pure chemical system. The exact correlation between the rate data for the tannage and pure chemical systems was demonstrated by means of correlation plots. Close correlation was revealed in the case of hide powder tannage while the smaller degree of correlation observed in the case of the pelt tannage systems was attributed to the modifying effects of diffusion, particularly on the initial reaction velocity. The effect of using boiled and aged chromium solutions in the tannages was to increase the initial rate of chroniill!l "fixation" apparently due to tho coordination of a dial species at each coordination site. After the initial reaction period, the two series showed a tendency to converge as in the case of the spectrophotometric studies on the acetate reaction. The convergence trend was regarded as indicative of the tendency for the chromium in fresh solutions to under go rapid olation to the ame level as in the boiled and aged solutions. The experimental observations made on the various systems lead to the following conclusions:- (a) The mechanism of coordination of the acetate radical ttrivalent chromium appears to involve the successive coordination of ligand to each of the chromium atoms of a diol complex, both coordination steps proceeding by second order reaction mechanisms. (b) At the pH levels at which the reaction is carried out, the formation of elated bodios is rapid so that reaction in the case of both fresh and aged solutions essentially occurs between an elated species and the ionised acetate radical. (c) Modificati0ns in the absorption spectrum of the reactant solution at the 570 mµ peak are directly related to coordination, while changes at the 420 mµ peak are related to the formation of loosely-bound hydroxo chromium compounds, the concentrations of which depend on the pH level. (d) The mechanism of chromium fixation in hide is essentially similar to that operating in the case of coordination of the acetate radical to chromium, involving attachment of chromium to the side chain acid r sidues of collagen. (e ) The effect of olation is to enhance the rate of chromium fixation by hide protein during the initial reaction stages and to render possible bridge formation between adjacent side chains by secondary coordination during the latter reaction stages. (f) Where pelt pieces are used instead of hide powder, the initial rate of chromium fixation is dominated by the rate of diffusion of chromium into the fibrous structure. It should be stressed that the observations made on the various reaction systems cannot be regarded as exhaustive and the conclusions are subject to further confirmation. Consequently, the present study is essentially of a preliminary nature, but it is felt that the need for further investigation along similar lines has been demonstrated.
- Full Text:
- Date Issued: 1962
- Authors: Russell, Allan Edward
- Date: 1962
- Subjects: Chemical kinetics , Chromium , Spectrophotometry , Electrophoresis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4493 , http://hdl.handle.net/10962/d1013101
- Description: The kinetics of the coordination reaction between the carboxyl group of the acetate radical and the trivalent chromium ion has been examined by independent methods at a temperature selected to yield reasonably accurate rate data. The study has been extended to an examination of the rate of chromium "fixation" by the carboxyl groups of hide collagen in a series of miniature tannages carried out under similar conditions for comparative purposes. The effect of olation of the chromium ions in solution on the kinetics of t he coordination reaction has also been examined. The rate of coordination of the acetate radical was followed by solvent extraction and spectrophotometric techniques over a range of concentration and pH levels. The rate data revealed a reaction having typical mass-action characteristics, the rate of reaction depending on the concentration levels of the chromium ion and the ionised acetate radical. An attempt made to distinguish a differential reaction rate in the case of a parallel reaction series using boiled and aged chromium nitrate reactant solutions, failed to reveal any significant differences between the series. The reactant solutions gave absorption spectra characteristic of the trivalent chromium ion with maxima in the 420 mµ and 570 mµ wavelength regions. The changes in optical density occurring in the vicinity of the maxima were followed spectrophotometrically, the height of the 570 mµ being found to increase during the course of reaction, while the height of the 420 mµ peak decreased. The variation in optical density at the 570 mµ peak was found to be directly related to the increase in concentration of the product complex in solution in accordance with the Baer-Bougher law, while the decrease in the height of the 420 mµ peak was related to the properties of unolated OH groups associated with the chromium complex as governed by pH and olation changes during the course of reaction. Boiled and aged chromium nitrate solutions gave reactant solutions having initial optical densities greater than those of the correspending fresh reactant solutions at the 570 mµ peak, and less than those of the fresh solutions at the 420 mµ peak. During the course of reaction, however, the two series converged to the same values. The equilibrium reaction solutions were subjected to paper electrophoretic study which indicated that all tho chromium was present in the form of cationic species. This finding was in accordance with stoicheiometric indications in the solvent extraction studies where coordination in a l : 1 ratio was reflected, giving rise to positively charged complex ions only. Making due allowance for band spreading the numbers of species predicted from the kinetic studies correspond with the electrophoretic patterns found. Application of the classical second order kinetic expression to the solvent extraction rate data, yielded plots having two distinctly linear sections, apparently indicating consecutive second order processes occurring in solution, contrary to the findings of previous workers who assign a first order mechanism to the reaction. This finding was consistent with the view that in the case of both the fresh and aged series, reaction consisted of successive coordination of an acetate radical to each chromium atom of a diol complex. Second order rate "constants" were calculated for each step and their dependency on pH level demonstrated. The findings of Hamm et al that these were first order reactions independent of acetate co'ncentration are believed to be due to their use of a large excess of acetate in their experiments. The kinetic study was further extended to an examination of the rate of "fixation"of trivalent chromium by the carboxyl groups of hide collagen under comparable conditions in a series of miniaturv tanning experiments in which the tannage substrate was provided in each of two physical forms:- (a) As hide powder where surface development was large, and (b) as prepared pelt pieces in which the fibrous weave pattern was retained. In view of the heterogeneity of the tannage systems, remarkable similarity was observed in the reaction course when compared with that of the acetate coordination studies, particularly in the case of the hide powder tannages. The dependency of the tannage rate data upon concentration and pH conditions was also found to be the same as in the case of the pure chemical system. The exact correlation between the rate data for the tannage and pure chemical systems was demonstrated by means of correlation plots. Close correlation was revealed in the case of hide powder tannage while the smaller degree of correlation observed in the case of the pelt tannage systems was attributed to the modifying effects of diffusion, particularly on the initial reaction velocity. The effect of using boiled and aged chromium solutions in the tannages was to increase the initial rate of chroniill!l "fixation" apparently due to tho coordination of a dial species at each coordination site. After the initial reaction period, the two series showed a tendency to converge as in the case of the spectrophotometric studies on the acetate reaction. The convergence trend was regarded as indicative of the tendency for the chromium in fresh solutions to under go rapid olation to the ame level as in the boiled and aged solutions. The experimental observations made on the various systems lead to the following conclusions:- (a) The mechanism of coordination of the acetate radical ttrivalent chromium appears to involve the successive coordination of ligand to each of the chromium atoms of a diol complex, both coordination steps proceeding by second order reaction mechanisms. (b) At the pH levels at which the reaction is carried out, the formation of elated bodios is rapid so that reaction in the case of both fresh and aged solutions essentially occurs between an elated species and the ionised acetate radical. (c) Modificati0ns in the absorption spectrum of the reactant solution at the 570 mµ peak are directly related to coordination, while changes at the 420 mµ peak are related to the formation of loosely-bound hydroxo chromium compounds, the concentrations of which depend on the pH level. (d) The mechanism of chromium fixation in hide is essentially similar to that operating in the case of coordination of the acetate radical to chromium, involving attachment of chromium to the side chain acid r sidues of collagen. (e ) The effect of olation is to enhance the rate of chromium fixation by hide protein during the initial reaction stages and to render possible bridge formation between adjacent side chains by secondary coordination during the latter reaction stages. (f) Where pelt pieces are used instead of hide powder, the initial rate of chromium fixation is dominated by the rate of diffusion of chromium into the fibrous structure. It should be stressed that the observations made on the various reaction systems cannot be regarded as exhaustive and the conclusions are subject to further confirmation. Consequently, the present study is essentially of a preliminary nature, but it is felt that the need for further investigation along similar lines has been demonstrated.
- Full Text:
- Date Issued: 1962
Newspapers in education programmes and South African youth: a survey of the relationship between South African school-goers and newspapers in Esikhawini, Kwazulu-Natal
- Authors: McComb, Roslin Vanessa
- Date: 1997
- Subjects: Newspapers in education -- South Africa , School children -- South Africa -- KwaZulu-Natal -- esikhawini , Newspapers in education
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3465 , http://hdl.handle.net/10962/d1002920 , Newspapers in education -- South Africa , School children -- South Africa -- KwaZulu-Natal -- esikhawini , Newspapers in education
- Description: This study examines the relationship which scholars have with newspapers against the background of a Newspapers in Education (NIE) programme in two black South African primary schools. Considering the presence of newspapers in the class as a medium of instruction, a number of factors are found to influence the -relationship which scholars have with newspapers. These factors are: scholars' access to newspapers; the nature of lessons using the newspaper; the character of the newspaper used in NIE and the context of education at the particular schools, including the attitudes and organisational abilities of both teachers and the principal. A description and analysis of this relationship is conducted in terms of the knowledge, attitudes and behaviour which scholars had -in te1ation to newspapers. This research is qualitative, undertaken from a constructivist-interpretative approach, and is set within international and South African contexts. The findings are relevant to understanding NIE programmes' interface with scholars' educational performance and with newspaper marketing objectives, as well as to the theorisation of NIE practices.
- Full Text:
- Date Issued: 1997
- Authors: McComb, Roslin Vanessa
- Date: 1997
- Subjects: Newspapers in education -- South Africa , School children -- South Africa -- KwaZulu-Natal -- esikhawini , Newspapers in education
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:3465 , http://hdl.handle.net/10962/d1002920 , Newspapers in education -- South Africa , School children -- South Africa -- KwaZulu-Natal -- esikhawini , Newspapers in education
- Description: This study examines the relationship which scholars have with newspapers against the background of a Newspapers in Education (NIE) programme in two black South African primary schools. Considering the presence of newspapers in the class as a medium of instruction, a number of factors are found to influence the -relationship which scholars have with newspapers. These factors are: scholars' access to newspapers; the nature of lessons using the newspaper; the character of the newspaper used in NIE and the context of education at the particular schools, including the attitudes and organisational abilities of both teachers and the principal. A description and analysis of this relationship is conducted in terms of the knowledge, attitudes and behaviour which scholars had -in te1ation to newspapers. This research is qualitative, undertaken from a constructivist-interpretative approach, and is set within international and South African contexts. The findings are relevant to understanding NIE programmes' interface with scholars' educational performance and with newspaper marketing objectives, as well as to the theorisation of NIE practices.
- Full Text:
- Date Issued: 1997
A comparison of nesting behaviour and prey selection in some Southern African species of Ammophila (Hymenoptera : Sphecidae)
- Authors: Weaving, Alan James Shelley
- Date: 1987
- Subjects: Hymenoptera
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5600 , http://hdl.handle.net/10962/d1002050
- Description: Nesting behaviour and prey selection was compared in eight species of Ammophila. The frequent sympatry of these species was a central point of interest in the study. Nest siting differed markedly in several species. A. ferrugineipes, A. dolichodera, A. dolichocephala and, probably, A. conifera nested mostly in open habitats, this being regarded as the most common situation for the majority of Ammophila. A. beniniensis was unusual in nesting in well vegetated habitats, A. vulcania doing so amongst small clumps of vegetation in otherwise open habitats. A. insignis nested in vertical banks or old animal burrows and A. braunsi utilised abandoned burrows of other wasps situated in non-friable clay soils. This is the first time such nest siting has been reported for Ammophila and each of these two species is consequently unique. Many aspects of nest construction behaviour, in particular methods of soil waste disposal, sealing of nests and their final coverage, differed interspecifically, in some cases intraspecifically, but often apparently in response to the habitat. With regard to nest provisioning strategies, all species hunted after digging their nests, except A. dolichodera which is the first Afrotropical Ammophila reported to hunt before excavating its nest. This brings the total number of the world's species of Ammophila showing this behaviour to three. This species, A. beniniensis, A. braunsi and A. vulcania provided one caterpillar per nest; the others supplied several, A. insignis being the only mass provisioner. A. ferrugineipes showed a form of progressive provisioning and maintained several nests at a time; it is the only Afrotropical species known so far to do so. Only two extra-limital species have been reported showing similar behaviour. The observed variations in provisioning strategies can most easily be explained in relation to the habitat. Investigation of prey selection showed that there was very little interspecific overlap in the species of caterpillars used for provisioning nests. This was shown to be due mainly to differing hunting habitat preferences. The various overall patterns of nesting behaviour, and variations in the different components within these patterns, were considered most likely to have resulted from allopatric speciation in different types of vegetation, the more advanced patterns arising in open habitats. The frequent occurrence of sympatry appears to be a reflection of a shifting distribution of mosaic patterns of vegetation types and the post-speciation spread of species. This influence of habitat on behaviour and prey selection has emphasised the need for caution in drawing phylogenetic conclusions from ethology. Further, these considerations provide an alternative to competition in attempting to explain the observed behaviour patterns and distribution of these wasps.
- Full Text:
- Date Issued: 1987
- Authors: Weaving, Alan James Shelley
- Date: 1987
- Subjects: Hymenoptera
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5600 , http://hdl.handle.net/10962/d1002050
- Description: Nesting behaviour and prey selection was compared in eight species of Ammophila. The frequent sympatry of these species was a central point of interest in the study. Nest siting differed markedly in several species. A. ferrugineipes, A. dolichodera, A. dolichocephala and, probably, A. conifera nested mostly in open habitats, this being regarded as the most common situation for the majority of Ammophila. A. beniniensis was unusual in nesting in well vegetated habitats, A. vulcania doing so amongst small clumps of vegetation in otherwise open habitats. A. insignis nested in vertical banks or old animal burrows and A. braunsi utilised abandoned burrows of other wasps situated in non-friable clay soils. This is the first time such nest siting has been reported for Ammophila and each of these two species is consequently unique. Many aspects of nest construction behaviour, in particular methods of soil waste disposal, sealing of nests and their final coverage, differed interspecifically, in some cases intraspecifically, but often apparently in response to the habitat. With regard to nest provisioning strategies, all species hunted after digging their nests, except A. dolichodera which is the first Afrotropical Ammophila reported to hunt before excavating its nest. This brings the total number of the world's species of Ammophila showing this behaviour to three. This species, A. beniniensis, A. braunsi and A. vulcania provided one caterpillar per nest; the others supplied several, A. insignis being the only mass provisioner. A. ferrugineipes showed a form of progressive provisioning and maintained several nests at a time; it is the only Afrotropical species known so far to do so. Only two extra-limital species have been reported showing similar behaviour. The observed variations in provisioning strategies can most easily be explained in relation to the habitat. Investigation of prey selection showed that there was very little interspecific overlap in the species of caterpillars used for provisioning nests. This was shown to be due mainly to differing hunting habitat preferences. The various overall patterns of nesting behaviour, and variations in the different components within these patterns, were considered most likely to have resulted from allopatric speciation in different types of vegetation, the more advanced patterns arising in open habitats. The frequent occurrence of sympatry appears to be a reflection of a shifting distribution of mosaic patterns of vegetation types and the post-speciation spread of species. This influence of habitat on behaviour and prey selection has emphasised the need for caution in drawing phylogenetic conclusions from ethology. Further, these considerations provide an alternative to competition in attempting to explain the observed behaviour patterns and distribution of these wasps.
- Full Text:
- Date Issued: 1987