Seasonal phenology of the diamondback moth, Plutella xylostella (L.), (Lepidoptera: Plutellidae), and its parasitoids on canola, Brassica napus (L.), in Gauteng province, South Africa
- Mosiane, S M, Kfir, R, Villet, Martin H
- Authors: Mosiane, S M , Kfir, R , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6856 , http://hdl.handle.net/10962/d1011139
- Description: Canola, Brassica napus L. (Brassicaceae), is a relativelynewcrop in SouthAfrica. Several insect pests, including diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), that attack cruciferous vegetables, also attack canola. The aims of this study were to determine the seasonal phenology of P. xylostella populations on canola, and the composition, relative abundance and seasonal phenology of parasitoids attacking P. xylostella on this crop. Diamondback moth adults were monitored with synthetic sex-pheromone traps. Larval and pupal populations of P. xylostella were monitored weekly for three years at Bapsfontein and Rietondale in Gauteng province. Samples of diamondback moth larvae, pupae and parasitoid cocoons were collected and transported to the laboratory. Parasitoids that emerged were identified and their incidence recorded. Berlese funnel catches were used as an indicator of the accuracy of the visual counts. The infestation level of P. xylostella larvae was high from May to August at Rietondale, while at Bapsfontein it was high from September to December. There was a high correlation (r=0.79, P<0.001) between pheromone trap catches and subsequent larval infestations at Bapsfontein. The pheromone traps indicated that diamondback moth adults were present throughout the year. Berlese funnel catches indicated that a large number of larvae, especially first instars, were overlooked during visual plant scouting. Parasitism rates were often very high, reaching 90–100 %. The following parasitoids were recorded from field-collected P. xylostella: the larval parasitoids Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) and Apanteles halfordi Ullyett (Hymenoptera: Braconidae), the larval/pupal parasitoids Diadegma mollipla (Holmgren) (Hymenoptera: Ichneumonidae) and Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae), the pupal parasitoid Diadromus collaris (Gravenhorst) (Hymenoptera: Ichneumonidae), and the hyperparasitoids Mesochorus sp. (Hymenoptera: Ichneumonidae) and Pteromalus sp. (Hymenoptera: Pteromalidae). Cotesia plutellae was the most abundant parasitoid throughout the study.
- Full Text:
- Date Issued: 2003
- Authors: Mosiane, S M , Kfir, R , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6856 , http://hdl.handle.net/10962/d1011139
- Description: Canola, Brassica napus L. (Brassicaceae), is a relativelynewcrop in SouthAfrica. Several insect pests, including diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), that attack cruciferous vegetables, also attack canola. The aims of this study were to determine the seasonal phenology of P. xylostella populations on canola, and the composition, relative abundance and seasonal phenology of parasitoids attacking P. xylostella on this crop. Diamondback moth adults were monitored with synthetic sex-pheromone traps. Larval and pupal populations of P. xylostella were monitored weekly for three years at Bapsfontein and Rietondale in Gauteng province. Samples of diamondback moth larvae, pupae and parasitoid cocoons were collected and transported to the laboratory. Parasitoids that emerged were identified and their incidence recorded. Berlese funnel catches were used as an indicator of the accuracy of the visual counts. The infestation level of P. xylostella larvae was high from May to August at Rietondale, while at Bapsfontein it was high from September to December. There was a high correlation (r=0.79, P<0.001) between pheromone trap catches and subsequent larval infestations at Bapsfontein. The pheromone traps indicated that diamondback moth adults were present throughout the year. Berlese funnel catches indicated that a large number of larvae, especially first instars, were overlooked during visual plant scouting. Parasitism rates were often very high, reaching 90–100 %. The following parasitoids were recorded from field-collected P. xylostella: the larval parasitoids Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) and Apanteles halfordi Ullyett (Hymenoptera: Braconidae), the larval/pupal parasitoids Diadegma mollipla (Holmgren) (Hymenoptera: Ichneumonidae) and Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae), the pupal parasitoid Diadromus collaris (Gravenhorst) (Hymenoptera: Ichneumonidae), and the hyperparasitoids Mesochorus sp. (Hymenoptera: Ichneumonidae) and Pteromalus sp. (Hymenoptera: Pteromalidae). Cotesia plutellae was the most abundant parasitoid throughout the study.
- Full Text:
- Date Issued: 2003
Self-Assembled Monolayers of Cobalt and Iron Phthalocyanine Complexes on Gold Electrodes
- Ozoemena, Kenneth I, Nyokong, Tebello, Westbroek, Philippe
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello , Westbroek, Philippe
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290363 , vital:56743 , xlink:href="https://doi.org/10.1002/elan.200302753"
- Description: The self-assembling of the octa(hydroxyethylthio)-metallophthalocyanine {MOHETPc (M=Co and Fe)} complexes and their similar analogues, octabutylthiometallophthalocyanine {MOBTPc (M=Co and Fe)} complexes on gold electrodes are investigated. Comparative surface voltammetric insights into their distinct self-assembling properties with respect to the passivation of Faradaic processes and surface coverages, including their solution electrochemistry, suggest different orientations and non-cleavage of their CS bonds. In the pH 2−9 range, the reversible [M(III)Pc(−2)]+ / [M(II)Pc(−2)] redox couples show potential shifts close to −59 mV / pH. The gold electrodes modified with the SAMs of these species show electrocatalytic activity towards the oxidation of thiols (L-cysteine, homocysteine and penicillamine) and thiocyanate in acidic media with detection limits in the region of 10−7–10−6 mol dm−3. These monolayers are stable and easily reproducible.
- Full Text:
- Date Issued: 2003
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello , Westbroek, Philippe
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290363 , vital:56743 , xlink:href="https://doi.org/10.1002/elan.200302753"
- Description: The self-assembling of the octa(hydroxyethylthio)-metallophthalocyanine {MOHETPc (M=Co and Fe)} complexes and their similar analogues, octabutylthiometallophthalocyanine {MOBTPc (M=Co and Fe)} complexes on gold electrodes are investigated. Comparative surface voltammetric insights into their distinct self-assembling properties with respect to the passivation of Faradaic processes and surface coverages, including their solution electrochemistry, suggest different orientations and non-cleavage of their CS bonds. In the pH 2−9 range, the reversible [M(III)Pc(−2)]+ / [M(II)Pc(−2)] redox couples show potential shifts close to −59 mV / pH. The gold electrodes modified with the SAMs of these species show electrocatalytic activity towards the oxidation of thiols (L-cysteine, homocysteine and penicillamine) and thiocyanate in acidic media with detection limits in the region of 10−7–10−6 mol dm−3. These monolayers are stable and easily reproducible.
- Full Text:
- Date Issued: 2003
Study South Africa
- International Education Association of South Africa (IEASA), Mason, Andy
- Authors: International Education Association of South Africa (IEASA) , Mason, Andy
- Date: 2003
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/65321 , vital:28745 , ISBN 0620247290
- Description: [Message from the Honorable Minister of Education, Prof. Kader Asmal]: It gives me pleasure to be able to once again give message of support for the Guide to South African Universities and Technikons. Government policy has placed higher education at the centre of the Human Resource Development Strategy. In the last edition I indicated the need to ensure that our system of higher education is relevant, accessible, efficient and provides the basis for lifelong learning. To this end we are embarking on a major transformation and reconstruction process to improve the capacity of our higher education institutions to respond nor only to national demands but also to the demands placed upon us by a globalised economy. TI1e envisaged higher education landscape should be better aligned to respond to the challenges of the constantly changing demands. The realisation of the African Union and the proposals contained in the New Programme for Africa Development calls for greater understanding of the international imperatives that will inform greater economic, political and social cooperation. All of this requires that higher education institutions should step up the pace in forging academic cooperation and linkages as well as providing an enabling environment for international students to study in South Africa. It also requires higher education institutions to ensure that the quality of the programmes offered matches or exceeds international benchmarks so that they become first choice institutions for students wanting an international experience. The initiative that the International Education Association of South Africa (IEASA) has undertaken together with the South African Universities Vice-Chancellors Association and the Committee of Technikon Principals is beginning to show some results. There has been an increase in the number of international students who seek study opportunities in our institutions. This can only strengthen our system as we gain more insight into international perspectives through these students. I wish all those involved in this endeavour success. , 3rd Edition
- Full Text:
- Date Issued: 2003
- Authors: International Education Association of South Africa (IEASA) , Mason, Andy
- Date: 2003
- Subjects: Education, Higher -- South Africa , Education and globalization -- South Africa Student mobility -- Africa International education -- South Africa Education, Higher -- International cooperation , Universities and colleges -- South Africa , Technical Institutes -- South Africa , Vocational guidance -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/65321 , vital:28745 , ISBN 0620247290
- Description: [Message from the Honorable Minister of Education, Prof. Kader Asmal]: It gives me pleasure to be able to once again give message of support for the Guide to South African Universities and Technikons. Government policy has placed higher education at the centre of the Human Resource Development Strategy. In the last edition I indicated the need to ensure that our system of higher education is relevant, accessible, efficient and provides the basis for lifelong learning. To this end we are embarking on a major transformation and reconstruction process to improve the capacity of our higher education institutions to respond nor only to national demands but also to the demands placed upon us by a globalised economy. TI1e envisaged higher education landscape should be better aligned to respond to the challenges of the constantly changing demands. The realisation of the African Union and the proposals contained in the New Programme for Africa Development calls for greater understanding of the international imperatives that will inform greater economic, political and social cooperation. All of this requires that higher education institutions should step up the pace in forging academic cooperation and linkages as well as providing an enabling environment for international students to study in South Africa. It also requires higher education institutions to ensure that the quality of the programmes offered matches or exceeds international benchmarks so that they become first choice institutions for students wanting an international experience. The initiative that the International Education Association of South Africa (IEASA) has undertaken together with the South African Universities Vice-Chancellors Association and the Committee of Technikon Principals is beginning to show some results. There has been an increase in the number of international students who seek study opportunities in our institutions. This can only strengthen our system as we gain more insight into international perspectives through these students. I wish all those involved in this endeavour success. , 3rd Edition
- Full Text:
- Date Issued: 2003
Synthesis, spectral and electrochemical properties of a new family of pyrrole substituted cobalt, iron, manganese, nickel and zinc phthalocyanine complexes
- Obirai, Joe, Rodrigues, Nazaré Pereira, Bedioui, Fethi, Nyokong, Tebello
- Authors: Obirai, Joe , Rodrigues, Nazaré Pereira , Bedioui, Fethi , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304852 , vital:58496 , xlink:href="https://0-doi.org.wam.seals.ac.za/10.1142/S1088424603000641"
- Description: A new family of pyrrole substituted metallophthalocyanine complexes, namely cobalt(II), iron(II), manganese(III), nickel(II) and zinc(II) tetrakis-4-(pyrrol-1-yl)phenoxy phthalocyanines (noted as M(TPhPyrPc), where M is the metallic cation) have been synthesized and fully characterized. In particular, the UV-visible spectra of the iron and nickel complexes showed extensive aggregation even at low concentrations. The cyclic voltammetry of the cobalt, iron and manganese complexes showed three to four redox couples assigned to metal and ring based processes. Spectroelectrochemistry of the manganese derivative confirmed that the synthesized complex is MnIII(TPhPyrPc-2) and that the reduction of MnII(TPhPyrPc-2) to be centred on the ring and rather than on the metal, forming the MnII(TPhPyrPc-4) species. Also, the electrochemical polymerization of these newly synthesized pyrrole-substituted phthalocyanines has been demonstrated in the case of the cobalt complex and the electrocatalytic activity of the obtained film has been tested towards the oxidation of L-cysteine.
- Full Text:
- Date Issued: 2003
- Authors: Obirai, Joe , Rodrigues, Nazaré Pereira , Bedioui, Fethi , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/304852 , vital:58496 , xlink:href="https://0-doi.org.wam.seals.ac.za/10.1142/S1088424603000641"
- Description: A new family of pyrrole substituted metallophthalocyanine complexes, namely cobalt(II), iron(II), manganese(III), nickel(II) and zinc(II) tetrakis-4-(pyrrol-1-yl)phenoxy phthalocyanines (noted as M(TPhPyrPc), where M is the metallic cation) have been synthesized and fully characterized. In particular, the UV-visible spectra of the iron and nickel complexes showed extensive aggregation even at low concentrations. The cyclic voltammetry of the cobalt, iron and manganese complexes showed three to four redox couples assigned to metal and ring based processes. Spectroelectrochemistry of the manganese derivative confirmed that the synthesized complex is MnIII(TPhPyrPc-2) and that the reduction of MnII(TPhPyrPc-2) to be centred on the ring and rather than on the metal, forming the MnII(TPhPyrPc-4) species. Also, the electrochemical polymerization of these newly synthesized pyrrole-substituted phthalocyanines has been demonstrated in the case of the cobalt complex and the electrocatalytic activity of the obtained film has been tested towards the oxidation of L-cysteine.
- Full Text:
- Date Issued: 2003
Synthesis, spectroscopy and photochemistry of octasubstituted thiol-derivatized phthalocyaninatozinc (II) complexes
- Ozoemena, Kenneth I, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290401 , vital:56746 , xlink:href="https://doi.org/10.1016/S1387-7003(03)00218-1"
- Description: Synthesis, spectroscopic and photochemical characterization of phenylthiol-derivatized zinc phthalocyanine complex: 2,3,9,10,16,17,23,24-octa(4-methylphenylthio-)phthalocyaninatozinc(II) [ZnPc(SC6H4CH3)8] (3a) and its alkanethiol derivative, 2,3,9,10,16,17,23,24-octabutylthiophthalocyaninatozinc(II) [ZnPc(SC4H9)8] (3b) are described. Spectroscopic analyses show that 3a has a higher aggregation tendency than 3b in organic solvents. Photochemical studies indicate that 3b is more photostable and more efficient at singlet oxygen generation than 3a.
- Full Text:
- Date Issued: 2003
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2003
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/290401 , vital:56746 , xlink:href="https://doi.org/10.1016/S1387-7003(03)00218-1"
- Description: Synthesis, spectroscopic and photochemical characterization of phenylthiol-derivatized zinc phthalocyanine complex: 2,3,9,10,16,17,23,24-octa(4-methylphenylthio-)phthalocyaninatozinc(II) [ZnPc(SC6H4CH3)8] (3a) and its alkanethiol derivative, 2,3,9,10,16,17,23,24-octabutylthiophthalocyaninatozinc(II) [ZnPc(SC4H9)8] (3b) are described. Spectroscopic analyses show that 3a has a higher aggregation tendency than 3b in organic solvents. Photochemical studies indicate that 3b is more photostable and more efficient at singlet oxygen generation than 3a.
- Full Text:
- Date Issued: 2003
The concentrations of the noble metals in Southern African flood-type basalts and MORB: implications for petrogenesis and magmatic sulphide exploration
- Maier, Wolfgand D, Barnes, Sarah-Jane, Marsh, Julian S
- Authors: Maier, Wolfgand D , Barnes, Sarah-Jane , Marsh, Julian S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150573 , vital:38985 , https://doi.org/10.1007/s00410-003-0480-z
- Description: Concentrations of the platinum-group elements have been determined in several suites of southern African flood-type basalts and mid-ocean ridge basalt (MORB), covering some 3 Ga of geologic evolution and including the Etendeka, Karoo, Soutpansberg, Machadodorp, Hekpoort, Ventersdorp and Dominion magmas.
- Full Text: false
- Date Issued: 2003
- Authors: Maier, Wolfgand D , Barnes, Sarah-Jane , Marsh, Julian S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150573 , vital:38985 , https://doi.org/10.1007/s00410-003-0480-z
- Description: Concentrations of the platinum-group elements have been determined in several suites of southern African flood-type basalts and mid-ocean ridge basalt (MORB), covering some 3 Ga of geologic evolution and including the Etendeka, Karoo, Soutpansberg, Machadodorp, Hekpoort, Ventersdorp and Dominion magmas.
- Full Text: false
- Date Issued: 2003
The geochemical structure of the Insizwa lobe of the Mount Ayliff complex with implications for the emplacement and evolution of the complex and its Ni-sulphide potential
- Marsh, Julian S, Allen, P, Fenner, N
- Authors: Marsh, Julian S , Allen, P , Fenner, N
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150556 , vital:38984 , https://doi.org/10.2113/106.4.409
- Description: Detailed petrographic, modal and geochemical studies on a number of deep boreholes (exceeding 1.2 km in some instances) along the southeastern margin of the Insizwa lobe of the Mount Ayliff Complex reveal the existence of a geochemical stratigraphy in the mafic intrusive rocks.
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S , Allen, P , Fenner, N
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150556 , vital:38984 , https://doi.org/10.2113/106.4.409
- Description: Detailed petrographic, modal and geochemical studies on a number of deep boreholes (exceeding 1.2 km in some instances) along the southeastern margin of the Insizwa lobe of the Mount Ayliff Complex reveal the existence of a geochemical stratigraphy in the mafic intrusive rocks.
- Full Text: false
- Date Issued: 2003
The influence of education on the interpretation of pharmaceutical pictograms for communicating medicine instructions:
- Dowse, Roslind, Ehlers, Martina S
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157014 , vital:40079 , DOI 10.1211/002235702810
- Description: To assess the influence of formal education on the interpretation of pharmaceutical pictograms.
- Full Text:
- Date Issued: 2003
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/157014 , vital:40079 , DOI 10.1211/002235702810
- Description: To assess the influence of formal education on the interpretation of pharmaceutical pictograms.
- Full Text:
- Date Issued: 2003
The OSS promise:
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159138 , vital:40271 , https://hdl.handle.net/10520/EJC146251
- Description: For Africa the attraction of open source software (OSS), is obvious. But for once, Internet intellectuals are not simply sounding off to annoy the rich north.
- Full Text:
- Date Issued: 2003
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159138 , vital:40271 , https://hdl.handle.net/10520/EJC146251
- Description: For Africa the attraction of open source software (OSS), is obvious. But for once, Internet intellectuals are not simply sounding off to annoy the rich north.
- Full Text:
- Date Issued: 2003
The stories in the details:
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159177 , vital:40274 , https://hdl.handle.net/10520/EJC146272
- Description: A famous journalism adage is that "the story is in the details". For the world Information Society, those details might be in the mind-blowing technological advances in recent years and the dizzying alternative news sources; and in the increased novelty in story telling.
- Full Text:
- Date Issued: 2003
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159177 , vital:40274 , https://hdl.handle.net/10520/EJC146272
- Description: A famous journalism adage is that "the story is in the details". For the world Information Society, those details might be in the mind-blowing technological advances in recent years and the dizzying alternative news sources; and in the increased novelty in story telling.
- Full Text:
- Date Issued: 2003
The unbalanced media diet: context gender
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158762 , vital:40226 , https://hdl.handle.net/10520/EJC146262
- Description: When you look at the Southern African "media diet" served up for Africans to consume, you discover some curious things about the differential reporting on men and women.
- Full Text:
- Date Issued: 2003
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158762 , vital:40226 , https://hdl.handle.net/10520/EJC146262
- Description: When you look at the Southern African "media diet" served up for Africans to consume, you discover some curious things about the differential reporting on men and women.
- Full Text:
- Date Issued: 2003
The union movement and South Africa's transition, 1994 - 2003
- NALEDI
- Authors: NALEDI
- Date: 2003
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/154168 , vital:39617
- Description: The new government faced enormous challenges when it came into office in 1994. For starters, the outgoing Apartheid leaders had thoroughly plundered the state coffers, awarding themselves and white civil servants massive pensions and 'golden handshakes'. The budget deficit was almost 9% of GDP The country/ had barely three weeks foreign exchange reserves, with a balance of payments crisis looming. The majority of inherited civil servants were generally hostile to the new government. The 'deep structures' of the State — by which I mean the ingrained habits and behaviour — were also generally hostile to the objectives of the democratic State. In addition, poverty levels were very high, and income inequality was among the worst in the world. And, of course, South Africa had the most institutionalised forms of racism in the world, which permeated through every law' and practice.
- Full Text:
- Date Issued: 2003
- Authors: NALEDI
- Date: 2003
- Subjects: NALEDI
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/154168 , vital:39617
- Description: The new government faced enormous challenges when it came into office in 1994. For starters, the outgoing Apartheid leaders had thoroughly plundered the state coffers, awarding themselves and white civil servants massive pensions and 'golden handshakes'. The budget deficit was almost 9% of GDP The country/ had barely three weeks foreign exchange reserves, with a balance of payments crisis looming. The majority of inherited civil servants were generally hostile to the new government. The 'deep structures' of the State — by which I mean the ingrained habits and behaviour — were also generally hostile to the objectives of the democratic State. In addition, poverty levels were very high, and income inequality was among the worst in the world. And, of course, South Africa had the most institutionalised forms of racism in the world, which permeated through every law' and practice.
- Full Text:
- Date Issued: 2003
The World Internet Project:
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159116 , vital:40269 , https://hdl.handle.net/10520/EJC146247
- Description: Here's a disturbing detail from the United Nations Development Programme (UNDP): only 1 in 118 Africans has access to the Internet. This ratio is actually skewed, partly because it averages out statistics in big countries (Egypt, South Africa) and the big cities (Johannesburg, Cairo, Cape Town, Lagos) with their poorer country cousins (Central African Republic, Mauritania).
- Full Text:
- Date Issued: 2003
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159116 , vital:40269 , https://hdl.handle.net/10520/EJC146247
- Description: Here's a disturbing detail from the United Nations Development Programme (UNDP): only 1 in 118 Africans has access to the Internet. This ratio is actually skewed, partly because it averages out statistics in big countries (Egypt, South Africa) and the big cities (Johannesburg, Cairo, Cape Town, Lagos) with their poorer country cousins (Central African Republic, Mauritania).
- Full Text:
- Date Issued: 2003
The writing is on the wall: ways that work
- Authors: Amner, Roderick J
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159102 , vital:40267 , https://hdl.handle.net/10520/EJC146296
- Description: When I proposed to 26 third-year journalism students that our writing class take inspiration from an idea pioneered in places as unfashionable and inhospitable as the former Soviet Union and Nepal, I should have expected the icy stares. But happily, within five weeks, this winter of classroom discontent, had begun to thaw into a tentative spring of journalistic and pedagogical innovation.
- Full Text:
- Date Issued: 2003
- Authors: Amner, Roderick J
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159102 , vital:40267 , https://hdl.handle.net/10520/EJC146296
- Description: When I proposed to 26 third-year journalism students that our writing class take inspiration from an idea pioneered in places as unfashionable and inhospitable as the former Soviet Union and Nepal, I should have expected the icy stares. But happily, within five weeks, this winter of classroom discontent, had begun to thaw into a tentative spring of journalistic and pedagogical innovation.
- Full Text:
- Date Issued: 2003
Thermal responses in some Eastern Cape African Cicadas (Hemiptera: Cicadidae)
- Sanborn, Allen F, Phillips, P K, Villet, Martin H
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6918 , http://hdl.handle.net/10962/d1011881
- Description: Thermal responses were measured in cicadas collected in the Eastern Cape Province of South Africa. The thermal responses of 22 species from 5 biomes were determined. Shade-seeking temperature was the most variable and related to the various biomes. Mean shade-seeking temperature was greatest for species inhabiting the thicket biome and lowest for species inhabiting the forest biome. The animals that live in the thicket biome may adapt to the greater thermal stress to take advantage of a habitat that permits lower predation pressure. There is a correlation between body size and shade-seeking temperatures with smaller species exhibiting lower thermal responses within a particular habitat. This may be related to the greater heat exchange in smaller species. Heat torpor temperatures did not differ between the various biomes.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6918 , http://hdl.handle.net/10962/d1011881
- Description: Thermal responses were measured in cicadas collected in the Eastern Cape Province of South Africa. The thermal responses of 22 species from 5 biomes were determined. Shade-seeking temperature was the most variable and related to the various biomes. Mean shade-seeking temperature was greatest for species inhabiting the thicket biome and lowest for species inhabiting the forest biome. The animals that live in the thicket biome may adapt to the greater thermal stress to take advantage of a habitat that permits lower predation pressure. There is a correlation between body size and shade-seeking temperatures with smaller species exhibiting lower thermal responses within a particular habitat. This may be related to the greater heat exchange in smaller species. Heat torpor temperatures did not differ between the various biomes.
- Full Text:
- Date Issued: 2003
Volcanic rocks of the Witwatersrand triad, South Africa I: description, classification and geochemical stratigraphy
- Bowen, Teral B, Marsh, Julian S, Bowen, Michael P, Eales, Hugh V
- Authors: Bowen, Teral B , Marsh, Julian S , Bowen, Michael P , Eales, Hugh V
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138682 , vital:37663 , https://doi.org/10.1016/0301-9268(86)90038-0
- Description: The Witwatersrand triad contains thick volcanic sequences confined largely to the Dominion Group at the base and the Ventersdorp Supergroup at the top. These volcanic sequences are of late-Archaean to early-Proterozoic age and are amongst the oldest supracrustal volcanic sequences erupted onto the Archaean Kaapvaal craton. The volcanic rocks have suffered low-grade greenschist facies metamorphism but primary textures and, in some samples, primary mineralogies are well preserved.
- Full Text: false
- Date Issued: 2003
- Authors: Bowen, Teral B , Marsh, Julian S , Bowen, Michael P , Eales, Hugh V
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138682 , vital:37663 , https://doi.org/10.1016/0301-9268(86)90038-0
- Description: The Witwatersrand triad contains thick volcanic sequences confined largely to the Dominion Group at the base and the Ventersdorp Supergroup at the top. These volcanic sequences are of late-Archaean to early-Proterozoic age and are amongst the oldest supracrustal volcanic sequences erupted onto the Archaean Kaapvaal craton. The volcanic rocks have suffered low-grade greenschist facies metamorphism but primary textures and, in some samples, primary mineralogies are well preserved.
- Full Text: false
- Date Issued: 2003
Volcanic rocks of the Witwatersrand Triad, South Africa. II: petrogenesis of mafic and felsic rocks of the Dominion Group
- Marsh, Julian S, Bowen, M P, Rogers, N W, Bowen, T B
- Authors: Marsh, Julian S , Bowen, M P , Rogers, N W , Bowen, T B
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140443 , vital:37889 , https://doi.org/10.1016/0301-9268(89)90075-2
- Description: A bimodal suite of volcanic rocks builds the bulk of the Dominion Group which, with an age of ∼ 2.72 Ga, is the oldest cover sequence overlying the granite-greenstone Archaean basement of the Kaapvaal craton in the western Transvaal, South Africa. The basic lavas are relatively rich in SiO2 (50–58%) and aphyric and exhibit a large compositional range. This variation is typically tholeiitic in that it is characterized by strong enrichment of Ti, Fe, and V in differentiated lavas.
- Full Text: false
- Date Issued: 2003
- Authors: Marsh, Julian S , Bowen, M P , Rogers, N W , Bowen, T B
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/140443 , vital:37889 , https://doi.org/10.1016/0301-9268(89)90075-2
- Description: A bimodal suite of volcanic rocks builds the bulk of the Dominion Group which, with an age of ∼ 2.72 Ga, is the oldest cover sequence overlying the granite-greenstone Archaean basement of the Kaapvaal craton in the western Transvaal, South Africa. The basic lavas are relatively rich in SiO2 (50–58%) and aphyric and exhibit a large compositional range. This variation is typically tholeiitic in that it is characterized by strong enrichment of Ti, Fe, and V in differentiated lavas.
- Full Text: false
- Date Issued: 2003
Weblogging is ‘We Media’:
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159134 , vital:40270 , https://hdl.handle.net/10520/EJC146248
- Description: "Blogging technology has begun to deliver on some of the wild promises about the Internet that were heard in the 1990s," wrote Matt Welch in the September/October issue of Columbia Journalism Review, America's leading media monitor published by the Graduate School of Journalism at Columbia University.
- Full Text:
- Date Issued: 2003
- Authors: Kyazze, Sim
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159134 , vital:40270 , https://hdl.handle.net/10520/EJC146248
- Description: "Blogging technology has begun to deliver on some of the wild promises about the Internet that were heard in the 1990s," wrote Matt Welch in the September/October issue of Columbia Journalism Review, America's leading media monitor published by the Graduate School of Journalism at Columbia University.
- Full Text:
- Date Issued: 2003
Why we need Di Versity the Superjourno:
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158740 , vital:40224 , https://hdl.handle.net/10520/EJC146308
- Description: Training and education is a serious subject, and there are thousands (millions) of words to be said about it. But when you're putting a magazine together you need visuals too, and how do you illustrate this subject?.
- Full Text:
- Date Issued: 2003
- Authors: Garman, Anthea
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158740 , vital:40224 , https://hdl.handle.net/10520/EJC146308
- Description: Training and education is a serious subject, and there are thousands (millions) of words to be said about it. But when you're putting a magazine together you need visuals too, and how do you illustrate this subject?.
- Full Text:
- Date Issued: 2003
‘South Africa's Vietnam’? Literary History and Cultural Memory of the Border War
- Authors: Baines, Gary F
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126987 , vital:35941 , https://doi.10.1080/17533170400505305
- Description: Density, population structure, growth, mortality and aspects of reproduction of the non-native amphipod Platorchestia platensis were studied for 20 consecutive months (October 2008 to May 2010) in the supralittoral wrack of the Knysna Estuary, South Africa. Amphipod density varied over the sampling period with the lowest numbers recorded in summer (January and February). Ovigerous females with embryos, and juveniles were found in most months with peaks in recruitment found in both April and October, suggesting that in Knysna this species is a biannual breeder. Average female size was significantly greater in winter, with larger females tending to brood more embryos. The largest adults (13.5 mm total length) were always male although the monthly sex ratio was nearly always female biased. Growth rate estimated from a cohort analysis was about 1 mm per month and monthly survival about 69%. The ability to reproduce all year round may be one reason why this introduced species has become established within this warm temperate estuary.
- Full Text:
- Date Issued: 2003
- Authors: Baines, Gary F
- Date: 2003
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126987 , vital:35941 , https://doi.10.1080/17533170400505305
- Description: Density, population structure, growth, mortality and aspects of reproduction of the non-native amphipod Platorchestia platensis were studied for 20 consecutive months (October 2008 to May 2010) in the supralittoral wrack of the Knysna Estuary, South Africa. Amphipod density varied over the sampling period with the lowest numbers recorded in summer (January and February). Ovigerous females with embryos, and juveniles were found in most months with peaks in recruitment found in both April and October, suggesting that in Knysna this species is a biannual breeder. Average female size was significantly greater in winter, with larger females tending to brood more embryos. The largest adults (13.5 mm total length) were always male although the monthly sex ratio was nearly always female biased. Growth rate estimated from a cohort analysis was about 1 mm per month and monthly survival about 69%. The ability to reproduce all year round may be one reason why this introduced species has become established within this warm temperate estuary.
- Full Text:
- Date Issued: 2003