A context for the 2011 compilation of reviews on the biological control of invasive alien plants in South Africa
- Moran, V Clifford, Hoffmann, John C, Hill, Martin P
- Authors: Moran, V Clifford , Hoffmann, John C , Hill, Martin P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451270 , vital:75035 , https://hdl.handle.net/10520/EJC32923
- Description: Besides this introduction, which gives a historical and contextual perspective, this compilation of reviews in African Entomology volume 19(2), comprises 28 papers, 24 of which provide accounts of recent (i.e. emphasising the period from 1999-2010) South African biological control projects against individual invasive alien plant species, or against taxonomically- or functionally-related groups of species. Three of the papers deal with issues related to research and implementation of biological control, namely: regulations and risk assessment; mapping; and cost-benefit analyses. The concluding paper is a complete catalogue, with summary statistics and key references, of all the target weeds and of the insect, mite and pathogen species (and subsidiary taxa) that have been implicated in biological control efforts against invasive alien plants in South Africa since 1913. This compilation is the third in a series of accounts of all the biological control programmes against invasive alien plants that have been undertaken in South Africa: the first, produced in 1991, reviewed progress to that date and the next, published in 1999, was a review of progress from 1990-1998. A comparison of the contents of these three review volumes is given in tabular form. The 2011 compilation contains reports on 13 novel programmes, in the sense that they have not been previously reviewed. Eight of these projects have focused on incipient weeds, or on rapidly-emerging weed species or groups of species, that have only recently been targeted for biological control. The increased scope and commitment to weed biological control research in South Africa has been largely the consequence of the sustained support provided by the Working for Water Programme of the South African Department of Water Affairs, over the last 15 years.
- Full Text:
- Date Issued: 2011
- Authors: Moran, V Clifford , Hoffmann, John C , Hill, Martin P
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451270 , vital:75035 , https://hdl.handle.net/10520/EJC32923
- Description: Besides this introduction, which gives a historical and contextual perspective, this compilation of reviews in African Entomology volume 19(2), comprises 28 papers, 24 of which provide accounts of recent (i.e. emphasising the period from 1999-2010) South African biological control projects against individual invasive alien plant species, or against taxonomically- or functionally-related groups of species. Three of the papers deal with issues related to research and implementation of biological control, namely: regulations and risk assessment; mapping; and cost-benefit analyses. The concluding paper is a complete catalogue, with summary statistics and key references, of all the target weeds and of the insect, mite and pathogen species (and subsidiary taxa) that have been implicated in biological control efforts against invasive alien plants in South Africa since 1913. This compilation is the third in a series of accounts of all the biological control programmes against invasive alien plants that have been undertaken in South Africa: the first, produced in 1991, reviewed progress to that date and the next, published in 1999, was a review of progress from 1990-1998. A comparison of the contents of these three review volumes is given in tabular form. The 2011 compilation contains reports on 13 novel programmes, in the sense that they have not been previously reviewed. Eight of these projects have focused on incipient weeds, or on rapidly-emerging weed species or groups of species, that have only recently been targeted for biological control. The increased scope and commitment to weed biological control research in South Africa has been largely the consequence of the sustained support provided by the Working for Water Programme of the South African Department of Water Affairs, over the last 15 years.
- Full Text:
- Date Issued: 2011
Aardvark burrows: a potential resource for animals in arid and semi-arid environments
- Whittington-Jones, Gareth M, Bernard, Ric T F, Parker, Daniel M
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443852 , vital:74166 , https://doi.org/10.1080/15627020.2011.11407509
- Description: Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.
- Full Text:
- Date Issued: 2011
- Authors: Whittington-Jones, Gareth M , Bernard, Ric T F , Parker, Daniel M
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443852 , vital:74166 , https://doi.org/10.1080/15627020.2011.11407509
- Description: Arid and semi-arid environments are characterized by extreme fluctuations in temperature and low rainfall, which present significant challenges to the animals inhabiting these areas. However, the presence of burrows may allow animals to avoid climatic extremes and predators and may act as valuable foraging sites. We assessed the microhabitat conditions (maximum and minimum temperature, relative humidity and seed abundance) of aardvark (Orycteropus afer) burrows in relation to paired non-burrow areas at three sites in South Africa. We also describe the extent to which they are used as resources by other vertebrates. Maximum temperatures were significantly lower and minimum temperatures and relative humidity values were significantly higher inside the burrows than outside. The concentration of seeds inside the burrows and at the paired non-burrow sites was similar. Twenty-seven vertebrate species (21 mammals, two birds, three reptiles and one amphibian) were recorded making use of the burrows and it is likely that these species accrue benefits (e.g. a buffered microclimate) from burrow use. However, our sampling was biased towards mammals and nocturnal species. Consequently, we recommend further work to establish the overall reliance of vertebrate taxa on aardvark burrows in arid and semi-arid environments.
- Full Text:
- Date Issued: 2011
Diet of largemouth bass, Micropterus salmoides (Centrarchidae), an invasive alien in the lower reaches of an Eastern Cape river, South Africa.
- Wasserman, Ryan J, Strydom, Nadine A, Weyl, Olaf L F
- Authors: Wasserman, Ryan J , Strydom, Nadine A , Weyl, Olaf L F
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443325 , vital:74108 , https://hdl.handle.net/10520/EJC18195
- Description: Largemouth bass (Micropterus salmoides) have been introduced to many South African river systems where they become invasive and pose a threat to native biota. The diets of small (32-138 mm TL) and large (192-448 mm TL) sized bass were analysed and compared in a marine fish nursery area in the lower Kowie River on the warm temperate coast of South Africa over a one-year period from March 2009 to February 2010. Dietary differences were detected between the two size groups. Amphipod sp. (% index of relative importance (IRI) = 69.2) and dipterans (Insecta) (%IRI = 21.9) dominated gut contents of small bass while larger bass preyed mostly on odonates (Insecta) (%IRI = 16.3) and the brachyuran Potamonautes sidneyi (%IRI = 80.0). Fish prey was of low importance during this study but comparisons with previous work on the lower Kowie River showed that when the river is flowing, young marine fish recruiting into the freshwater from the estuary become important prey items. These data suggest that in the lower Kowie River bass utilize invertebrate prey at low fish prey abundance and opportunistically feed on migrant fish when these are available.
- Full Text:
- Date Issued: 2011
- Authors: Wasserman, Ryan J , Strydom, Nadine A , Weyl, Olaf L F
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/443325 , vital:74108 , https://hdl.handle.net/10520/EJC18195
- Description: Largemouth bass (Micropterus salmoides) have been introduced to many South African river systems where they become invasive and pose a threat to native biota. The diets of small (32-138 mm TL) and large (192-448 mm TL) sized bass were analysed and compared in a marine fish nursery area in the lower Kowie River on the warm temperate coast of South Africa over a one-year period from March 2009 to February 2010. Dietary differences were detected between the two size groups. Amphipod sp. (% index of relative importance (IRI) = 69.2) and dipterans (Insecta) (%IRI = 21.9) dominated gut contents of small bass while larger bass preyed mostly on odonates (Insecta) (%IRI = 16.3) and the brachyuran Potamonautes sidneyi (%IRI = 80.0). Fish prey was of low importance during this study but comparisons with previous work on the lower Kowie River showed that when the river is flowing, young marine fish recruiting into the freshwater from the estuary become important prey items. These data suggest that in the lower Kowie River bass utilize invertebrate prey at low fish prey abundance and opportunistically feed on migrant fish when these are available.
- Full Text:
- Date Issued: 2011
Dimethylglyoxime based ion-imprinted polymer for the determination of Ni(II) ions from aqueous samples
- Rammika, Modise, Darko, Godfrey, Tshentu, Zenixole R, Sewry, Joyce D, Torto, Nelson
- Authors: Rammika, Modise , Darko, Godfrey , Tshentu, Zenixole R , Sewry, Joyce D , Torto, Nelson
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6590 , http://hdl.handle.net/10962/d1004173
- Description: A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was synthesised by the bulk polymerisation method. The morphology of the Ni(II)-DMG IIP and non-imprinted polymer were observed by scanning electron microscopy and the chemical structures were evaluated by infrared spectroscopy. Selectivity of the Ni(II)-DMG IIP was studied by analysing, using an inductively coupled plasma-optical emission spectrometer, for Ni(II) ions that were spiked with varying concentrations of Co(II), Cu(II), Zn(II), Pd(II), Fe(II), Ca(II), Mg(II), Na(I) and K(I) in aqueous samples. The studies revealed Ni(II) recoveries ranging from 93 to 100% in aqueous solutions with minimal interference from competing ions. Enrichment factors ranged from 2 to 18 with a binding capacity of 120 μg∙g−1. Co(II) was the only ion found to slightly interfere with the determination of Ni(II). Selectivity studies confirmed that the Ni(II)-DMG IIP had very good selectivity, characterised by %RSD of less than 5%. The limits of detection and quantification were 3x10-4 μg∙mℓ−1 and 9x10-4 μg∙mℓ−1, respectively. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3) and the concentration of Ni(II) obtained was in close agreement with the certified one. The Ni(II)-DMG IIP was successfully employed to trap Ni(II) ions from a matrix of sea, river and sewage water. It is believed that the Ni(II)-DMG IIP has potential to be used as sorbent material for pre-concentration of Ni(II) ions from aqueous solutions by solid-phase extraction.
- Full Text:
- Date Issued: 2011
- Authors: Rammika, Modise , Darko, Godfrey , Tshentu, Zenixole R , Sewry, Joyce D , Torto, Nelson
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6590 , http://hdl.handle.net/10962/d1004173
- Description: A Ni(II)-dimethylglyoxime ion-imprinted polymer {Ni(II)-DMG IIP} was synthesised by the bulk polymerisation method. The morphology of the Ni(II)-DMG IIP and non-imprinted polymer were observed by scanning electron microscopy and the chemical structures were evaluated by infrared spectroscopy. Selectivity of the Ni(II)-DMG IIP was studied by analysing, using an inductively coupled plasma-optical emission spectrometer, for Ni(II) ions that were spiked with varying concentrations of Co(II), Cu(II), Zn(II), Pd(II), Fe(II), Ca(II), Mg(II), Na(I) and K(I) in aqueous samples. The studies revealed Ni(II) recoveries ranging from 93 to 100% in aqueous solutions with minimal interference from competing ions. Enrichment factors ranged from 2 to 18 with a binding capacity of 120 μg∙g−1. Co(II) was the only ion found to slightly interfere with the determination of Ni(II). Selectivity studies confirmed that the Ni(II)-DMG IIP had very good selectivity, characterised by %RSD of less than 5%. The limits of detection and quantification were 3x10-4 μg∙mℓ−1 and 9x10-4 μg∙mℓ−1, respectively. The accuracy of the method was validated by analysing a custom solution of certified reference material (SEP-3) and the concentration of Ni(II) obtained was in close agreement with the certified one. The Ni(II)-DMG IIP was successfully employed to trap Ni(II) ions from a matrix of sea, river and sewage water. It is believed that the Ni(II)-DMG IIP has potential to be used as sorbent material for pre-concentration of Ni(II) ions from aqueous solutions by solid-phase extraction.
- Full Text:
- Date Issued: 2011
Diverse pollination systems of the twin-spurred orchid genus Satyrium in African grasslands
- Johnson, S.D, Peter, C.I, Ellis, A.G, Boberg, E, Botes, C, Van der Niet, T
- Authors: Johnson, S.D , Peter, C.I , Ellis, A.G , Boberg, E , Botes, C , Van der Niet, T
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6558 , http://hdl.handle.net/10962/d1006025 , http://dx.doi.org/10.1007/s00606-010-0411-1
- Description: The large terrestrial orchid genus Satyrium underwent evolutionary radiations in the Cape floral region and the grasslands of southern and eastern Africa. These radiations were accompanied by tremendous diversification of the unusual twin-spurred flowers that characterize the genus, but pollination data required to interpret these patterns of floral evolution have been lacking for grassland species in the genus. Here we document pollinators, nectar properties, and levels of pollination success for 11 grassland Satyrium species in southern and south-central Africa. Pollinators of these species include bees, beetles, butterflies, hawkmoths, noctuid moths, long-proboscid flies, and sunbirds. Most species appear to be specialized for pollination by one functional pollinator group. Long-proboscid fly pollination systems are reported for the first time in Satyrium (in S. macrophyllum and a high-altitude form of S. neglectum). Floral morphology, especially spur length and rostellum structure, differs markedly among plants with different pollinators, while nectar volume, concentration, and sugar composition are fairly uniform across species. Most taxa exhibited high levels of pollination success (>50% of flowers pollinated), a trend that can be attributed to the presence of nectar in the twin spurs.
- Full Text:
- Date Issued: 2011
- Authors: Johnson, S.D , Peter, C.I , Ellis, A.G , Boberg, E , Botes, C , Van der Niet, T
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6558 , http://hdl.handle.net/10962/d1006025 , http://dx.doi.org/10.1007/s00606-010-0411-1
- Description: The large terrestrial orchid genus Satyrium underwent evolutionary radiations in the Cape floral region and the grasslands of southern and eastern Africa. These radiations were accompanied by tremendous diversification of the unusual twin-spurred flowers that characterize the genus, but pollination data required to interpret these patterns of floral evolution have been lacking for grassland species in the genus. Here we document pollinators, nectar properties, and levels of pollination success for 11 grassland Satyrium species in southern and south-central Africa. Pollinators of these species include bees, beetles, butterflies, hawkmoths, noctuid moths, long-proboscid flies, and sunbirds. Most species appear to be specialized for pollination by one functional pollinator group. Long-proboscid fly pollination systems are reported for the first time in Satyrium (in S. macrophyllum and a high-altitude form of S. neglectum). Floral morphology, especially spur length and rostellum structure, differs markedly among plants with different pollinators, while nectar volume, concentration, and sugar composition are fairly uniform across species. Most taxa exhibited high levels of pollination success (>50% of flowers pollinated), a trend that can be attributed to the presence of nectar in the twin spurs.
- Full Text:
- Date Issued: 2011
Enhancing the Configuration and Design of Sound Systems through Simulation
- Otten, Frederick, Foss, Richard
- Authors: Otten, Frederick , Foss, Richard
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427125 , vital:72416 , https://www.aes.org/e-lib/browse.cfm?elib=15848
- Description: Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet. Bandwidth utilsation and latency need to be considered. Network Simulation can be used to accurately model a network and return such information. This paper discusses a software system which has been developed to create a simulation of a network using the AES-X170 protocol for command and control. This system shows information about bandwidth and latency and is able to detect problems with parameter relationships. It also provides the ability to perform offline editing. These features significantly enhance audio engineers' ability to effectively design, configure and evaluate sound systems.
- Full Text:
- Date Issued: 2011
- Authors: Otten, Frederick , Foss, Richard
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427125 , vital:72416 , https://www.aes.org/e-lib/browse.cfm?elib=15848
- Description: Audio Engineers are required to design and deploy large multi-channel sound systems which meet a set of requirements and use networking technologies such as Firewire and Ethernet. Bandwidth utilsation and latency need to be considered. Network Simulation can be used to accurately model a network and return such information. This paper discusses a software system which has been developed to create a simulation of a network using the AES-X170 protocol for command and control. This system shows information about bandwidth and latency and is able to detect problems with parameter relationships. It also provides the ability to perform offline editing. These features significantly enhance audio engineers' ability to effectively design, configure and evaluate sound systems.
- Full Text:
- Date Issued: 2011
Ilam's Archival Revitalisation: the past five years at the International Library of African Music
- Authors: Still-Drewett, F
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6983 , http://hdl.handle.net/10962/d1006719
- Description: The International Library for African Music (ILAM) was begun in 1954 by ethnomusicologist Hugh Tracey (1903–1977). Since 2007, an active set of projects in preservation and digitisation of both sound and photographic archives have meant that this highly important archive of traditional African music has been stabilized and conserved. New outreach education projects are helping distribute the wealth of the collection back to the African people. ILAM now has a more secure future and makes seminal contributions in the fields of research, publication and education for African music. French Abstract La Bibliothèque Internationale pour la Musique Africaine (ILAM) a été établie en 1954 par l’ethnomusicologue Hugh Tracey (1903–1977). Depuis 2007, un ensemble de projets actifs dans la préservation et la numérisation des archives sonores et photographiques, a eu comme résultat que ces archives très importantes de la musique traditionnelle africaine ont été stabilisées et conservées. De nouveaux projets d’éducation et de sensibilisation aident à distribuer la richesse de cette collection à la population africaine. ILAM a maintenant un avenir plus sûr et apporte une contribution fondamentale dans les domaines de la recherche, la publication et l’enseignement de la musique africaine. German Abstract Die International Library for African Music (ILAM) wurde im Jahr 1954 durch den Musi kethnolo - gen Hugh Tracey (1903–1977) gegründet. Seit 2007 laufende Projekte zur Bestandssicherung und Digitalisierung des Schall- und Fotoarchivs helfen, dieses überaus wichtige Archiv für traditionelle afrikanische Musik zu erhalten und in seiner Existenz zu stabilisieren. Neue, nach außen wirkende Bildungsprojekte tragen dazu bei, den Reichtum der Sammlung an die afrikanische Bevölkerung zurückzugeben. Durch seine nun gesicherte Zukunft kann ILAM für die afrikanische Musik grundlegende Beiträge in Forschung, Veröffentlichung und Bildung leisten. Afrikaans Abstract Die International Library of African Music (ILAM) is in 1954 deur die etnomusikoloog, Hugh Tracey (1903–1977), gestig. Aktiewe preserverings- en digitaliseringsprojekte van beide klank- en foto-argiewe sedert 2007, het tot gevolg gehad dat hierdie hoogs belangrike argief van tradisionele Afrikamusiek gestabiliseer en bewaar kon word. Nuwe ontwikkelings-uitreikprojekte dra daartoe by dat die rykdom van hierdie versameling teruggeploeg word aan Afrika. ILAM het tans ‘n meer versekerde toekoms en lewer invloedryke bydraes op die gebied van navorsing, publikasie en opleiding in Afrikamusiek. IsiXhosa Abstract Ithala lehlabathi lomculo wase-Afrika, i- International Library for African Music (ILAM) laqalwa ngo- 1954 yingcali yomculo weentlanga ngeentlanga, uHugh Tracey (1903–1977). Ukususela ngo-2007 umsebenzi wokulondoloza nokugcina ngekhompyutha isandi seengoma kwakunye neefoto uthetha ukuba le mbali ibalulekileyo kumculo we-Afrika wemveli iqiniselwe kwaye igcinwe ngononophelo. Iiprojekti ezintsha zokolulela isandla kwabanye abantu ziyanceda ekusasazeni le ndyebo kwabo bantu isuka kubo, ama-Afrika. Ngoku i-ILAM inekamva elingagunqgiyo kwaye inegalelo elibonakalayo kuphando, upapasho nemfundo ngomculo wase-Afrika.
- Full Text:
- Date Issued: 2011
- Authors: Still-Drewett, F
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6983 , http://hdl.handle.net/10962/d1006719
- Description: The International Library for African Music (ILAM) was begun in 1954 by ethnomusicologist Hugh Tracey (1903–1977). Since 2007, an active set of projects in preservation and digitisation of both sound and photographic archives have meant that this highly important archive of traditional African music has been stabilized and conserved. New outreach education projects are helping distribute the wealth of the collection back to the African people. ILAM now has a more secure future and makes seminal contributions in the fields of research, publication and education for African music. French Abstract La Bibliothèque Internationale pour la Musique Africaine (ILAM) a été établie en 1954 par l’ethnomusicologue Hugh Tracey (1903–1977). Depuis 2007, un ensemble de projets actifs dans la préservation et la numérisation des archives sonores et photographiques, a eu comme résultat que ces archives très importantes de la musique traditionnelle africaine ont été stabilisées et conservées. De nouveaux projets d’éducation et de sensibilisation aident à distribuer la richesse de cette collection à la population africaine. ILAM a maintenant un avenir plus sûr et apporte une contribution fondamentale dans les domaines de la recherche, la publication et l’enseignement de la musique africaine. German Abstract Die International Library for African Music (ILAM) wurde im Jahr 1954 durch den Musi kethnolo - gen Hugh Tracey (1903–1977) gegründet. Seit 2007 laufende Projekte zur Bestandssicherung und Digitalisierung des Schall- und Fotoarchivs helfen, dieses überaus wichtige Archiv für traditionelle afrikanische Musik zu erhalten und in seiner Existenz zu stabilisieren. Neue, nach außen wirkende Bildungsprojekte tragen dazu bei, den Reichtum der Sammlung an die afrikanische Bevölkerung zurückzugeben. Durch seine nun gesicherte Zukunft kann ILAM für die afrikanische Musik grundlegende Beiträge in Forschung, Veröffentlichung und Bildung leisten. Afrikaans Abstract Die International Library of African Music (ILAM) is in 1954 deur die etnomusikoloog, Hugh Tracey (1903–1977), gestig. Aktiewe preserverings- en digitaliseringsprojekte van beide klank- en foto-argiewe sedert 2007, het tot gevolg gehad dat hierdie hoogs belangrike argief van tradisionele Afrikamusiek gestabiliseer en bewaar kon word. Nuwe ontwikkelings-uitreikprojekte dra daartoe by dat die rykdom van hierdie versameling teruggeploeg word aan Afrika. ILAM het tans ‘n meer versekerde toekoms en lewer invloedryke bydraes op die gebied van navorsing, publikasie en opleiding in Afrikamusiek. IsiXhosa Abstract Ithala lehlabathi lomculo wase-Afrika, i- International Library for African Music (ILAM) laqalwa ngo- 1954 yingcali yomculo weentlanga ngeentlanga, uHugh Tracey (1903–1977). Ukususela ngo-2007 umsebenzi wokulondoloza nokugcina ngekhompyutha isandi seengoma kwakunye neefoto uthetha ukuba le mbali ibalulekileyo kumculo we-Afrika wemveli iqiniselwe kwaye igcinwe ngononophelo. Iiprojekti ezintsha zokolulela isandla kwabanye abantu ziyanceda ekusasazeni le ndyebo kwabo bantu isuka kubo, ama-Afrika. Ngoku i-ILAM inekamva elingagunqgiyo kwaye inegalelo elibonakalayo kuphando, upapasho nemfundo ngomculo wase-Afrika.
- Full Text:
- Date Issued: 2011
Network neutral control over quality of service networks
- Foulkes, Phillip, Foss, Richard, Gurdan, Robby
- Authors: Foulkes, Phillip , Foss, Richard , Gurdan, Robby
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427166 , vital:72419 , https://www.aes.org/e-lib/online/browse.cfm?elib=16151
- Description: Creating interoperability between two standards-based network technologies, IEEE 1394 Firewire and Ethernet Audio/Video Bridging (AVB), allows them to exist simultaneously in a single application configuration. While both technologies provide the transport of synchronized, low-latency, real-time audio and video data, they have different approaches to enabling this transport. By using a compatible audio gateway with a common control protocol, audio devices on these disparate networks can be connected and controlled.
- Full Text:
- Date Issued: 2011
- Authors: Foulkes, Phillip , Foss, Richard , Gurdan, Robby
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427166 , vital:72419 , https://www.aes.org/e-lib/online/browse.cfm?elib=16151
- Description: Creating interoperability between two standards-based network technologies, IEEE 1394 Firewire and Ethernet Audio/Video Bridging (AVB), allows them to exist simultaneously in a single application configuration. While both technologies provide the transport of synchronized, low-latency, real-time audio and video data, they have different approaches to enabling this transport. By using a compatible audio gateway with a common control protocol, audio devices on these disparate networks can be connected and controlled.
- Full Text:
- Date Issued: 2011
Selective removal of chromium (VI) from sulphates and other metal anions using an ion-imprinted polymer
- Pakade, Vusumzi E, Cukrowska, Ewa, Darkwa, James, Torto, Nelson, Chimuka, Luke
- Authors: Pakade, Vusumzi E , Cukrowska, Ewa , Darkwa, James , Torto, Nelson , Chimuka, Luke
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6588 , http://hdl.handle.net/10962/d1004171
- Description: A linear copolymer was prepared from 4-vinylpyridine and styrene. An ion-imprinted polymer (IIP) specific for Cr (VI) adsorption was prepared by copolymerisation of the quaternised linear copolymer (quaternised with 1,4-chlorobutane), 2-vinylpyridine functional monomer and ethylene glycol dimethacrylate (EGDMA), as the cross-linking monomer, in the presence of 1,1’-azobis(cyclohexanecarbonitrile) as initiator. Ammonium dichromate and aqueous methanol were used as a template and porogenic solvent, respectively. Leaching of the chromate template from the polymer particles was achieved with successive stirring of the ion-imprinted polymer (IIP) particles in 4 M HNO3 solutions to obtain leached materials, which were then used for selective rebinding of Cr (VI) ions from aqueous solutions. Similarly, the non-imprinted polymer/ control polymer (NIP/CP) material was also prepared under exactly the same conditions as the IIP but without the chromate anion template. Various parameters, such as solution pH, initial concentration, aqueous phase volume, sorbent dosage, contact time and leaching solution volumes, were investigated. Scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, BET surface area and pore size analysis were used for the characterisation of IIP (both unleached and leached) and CP materials. Optimal parameters were as follows: solution pH, 3; contact time, 120 min; eluent, 20 mℓ of 0.1 M NaOH; and sorbent amount, 125 mg. Maximum retention capacity of IIP and CP was 37.58 and 25.44 mg∙g-1, respectively. The extraction efficiencies of the IIP and CP were compared using a batch and SPE mode of extraction. In the absence of high concentrations of ions, especially sulphate ions, both CP and IIP demonstrated no differences in binding of Cr (VI), which was almost 100%. However, in the presence of high concentrations of sulphate ions, the selectivity on the CP completely collapsed. The study clearly demonstrates the suitably of the developed IIP for selective extraction of Cr (VI) in complex samples such as those from acid mine drainage. The selectivity was also compared by direct injection of the real-world sample, both spiked and non-spiked, into that obtained after IIP selective extraction. Despite the method’s very low detection limits for direct injection (below 1 μg∙ℓ-1), no Cr (VI) was obtained. However, after IIP selective extraction, spiked Cr (VI) was detected in the spiked sample.
- Full Text:
- Date Issued: 2011
- Authors: Pakade, Vusumzi E , Cukrowska, Ewa , Darkwa, James , Torto, Nelson , Chimuka, Luke
- Date: 2011
- Language: English
- Type: Article
- Identifier: vital:6588 , http://hdl.handle.net/10962/d1004171
- Description: A linear copolymer was prepared from 4-vinylpyridine and styrene. An ion-imprinted polymer (IIP) specific for Cr (VI) adsorption was prepared by copolymerisation of the quaternised linear copolymer (quaternised with 1,4-chlorobutane), 2-vinylpyridine functional monomer and ethylene glycol dimethacrylate (EGDMA), as the cross-linking monomer, in the presence of 1,1’-azobis(cyclohexanecarbonitrile) as initiator. Ammonium dichromate and aqueous methanol were used as a template and porogenic solvent, respectively. Leaching of the chromate template from the polymer particles was achieved with successive stirring of the ion-imprinted polymer (IIP) particles in 4 M HNO3 solutions to obtain leached materials, which were then used for selective rebinding of Cr (VI) ions from aqueous solutions. Similarly, the non-imprinted polymer/ control polymer (NIP/CP) material was also prepared under exactly the same conditions as the IIP but without the chromate anion template. Various parameters, such as solution pH, initial concentration, aqueous phase volume, sorbent dosage, contact time and leaching solution volumes, were investigated. Scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy, BET surface area and pore size analysis were used for the characterisation of IIP (both unleached and leached) and CP materials. Optimal parameters were as follows: solution pH, 3; contact time, 120 min; eluent, 20 mℓ of 0.1 M NaOH; and sorbent amount, 125 mg. Maximum retention capacity of IIP and CP was 37.58 and 25.44 mg∙g-1, respectively. The extraction efficiencies of the IIP and CP were compared using a batch and SPE mode of extraction. In the absence of high concentrations of ions, especially sulphate ions, both CP and IIP demonstrated no differences in binding of Cr (VI), which was almost 100%. However, in the presence of high concentrations of sulphate ions, the selectivity on the CP completely collapsed. The study clearly demonstrates the suitably of the developed IIP for selective extraction of Cr (VI) in complex samples such as those from acid mine drainage. The selectivity was also compared by direct injection of the real-world sample, both spiked and non-spiked, into that obtained after IIP selective extraction. Despite the method’s very low detection limits for direct injection (below 1 μg∙ℓ-1), no Cr (VI) was obtained. However, after IIP selective extraction, spiked Cr (VI) was detected in the spiked sample.
- Full Text:
- Date Issued: 2011
The PINIT domain of PIAS3: structure-function analysis of its interaction with STAT3
- Mautsa, Nicodemus, Prinsloo, Earl, Tastan Bishop, Özlem, Blatch, Gregory L
- Authors: Mautsa, Nicodemus , Prinsloo, Earl , Tastan Bishop, Özlem , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148082 , vital:38708 , DOI: 10.1002/jmr.1111
- Description: The protein inhibitor of activated signal transducer and activator of transcription 3 (PIAS3) regulates the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) which regulates transcription of genes involved in cell growth, proliferation and apoptosis. The conserved proline, isoleucine, asparagine, isoleucine, threonine (PINIT) domain of PIAS3 is thought to promote STAT3–PIAS3 interaction.
- Full Text:
- Date Issued: 2011
- Authors: Mautsa, Nicodemus , Prinsloo, Earl , Tastan Bishop, Özlem , Blatch, Gregory L
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148082 , vital:38708 , DOI: 10.1002/jmr.1111
- Description: The protein inhibitor of activated signal transducer and activator of transcription 3 (PIAS3) regulates the transcriptional activity of signal transducer and activator of transcription 3 (STAT3) which regulates transcription of genes involved in cell growth, proliferation and apoptosis. The conserved proline, isoleucine, asparagine, isoleucine, threonine (PINIT) domain of PIAS3 is thought to promote STAT3–PIAS3 interaction.
- Full Text:
- Date Issued: 2011
The xfn connection management and control protocol
- Foss, Richard, Gurdan, Robby, Klinkradt, Bradley, Chigwamba, Nyasha
- Authors: Foss, Richard , Gurdan, Robby , Klinkradt, Bradley , Chigwamba, Nyasha
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427137 , vital:72417 , https://www.aes.org/e-lib/browse.cfm?elib=16143
- Description: With the advent of digital networks that link audio devices, there is a need for a protocol that integrates control and connection management, enables the streaming of all media content such as audio and video between devices from different manufacturers, and that provides a common approach to the control of these devices. This paper describes such a protocol, named XFN, currently being standardized as part of the AES X170 project. XFN is an IP-based peer to peer network protocol, in which any device on the network may send or receive connection management, control, and monitoring messages. Essential to the XFN protocol is the fact that each parameter in a device can be addressed via a hierarchical structure that reflects the functional layout of the device.
- Full Text:
- Date Issued: 2011
- Authors: Foss, Richard , Gurdan, Robby , Klinkradt, Bradley , Chigwamba, Nyasha
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427137 , vital:72417 , https://www.aes.org/e-lib/browse.cfm?elib=16143
- Description: With the advent of digital networks that link audio devices, there is a need for a protocol that integrates control and connection management, enables the streaming of all media content such as audio and video between devices from different manufacturers, and that provides a common approach to the control of these devices. This paper describes such a protocol, named XFN, currently being standardized as part of the AES X170 project. XFN is an IP-based peer to peer network protocol, in which any device on the network may send or receive connection management, control, and monitoring messages. Essential to the XFN protocol is the fact that each parameter in a device can be addressed via a hierarchical structure that reflects the functional layout of the device.
- Full Text:
- Date Issued: 2011
Towards a standard model for networked audio devices
- Eales, Andrew, Foss, Richard
- Authors: Eales, Andrew , Foss, Richard
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427151 , vital:72418 , https://www.aes.org/e-lib/online/browse.cfm?elib=16144
- Description: Different control protocols for networked audio devices typically emphasize particular aspects of a device, such as the representation of parameter data, or a representation of the functional structure of a device. A sophisticated device model must represent parameter data, device structure and the visual presentation of controls. Parameter data should be related to the device structure, while also being represented within a flexible, logical hierarchy. The development of a standard device model is proposed and discussed with reference to the OSC, IEC62379, ACN and X170 control protocols. This abstract model is independent of any specific control protocol, and provides support for interoperability between control protocols. The proposed model is also discussed within the context of an object-based approach to service enumeration and control using an associative, shared memory model.
- Full Text:
- Date Issued: 2011
- Authors: Eales, Andrew , Foss, Richard
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427151 , vital:72418 , https://www.aes.org/e-lib/online/browse.cfm?elib=16144
- Description: Different control protocols for networked audio devices typically emphasize particular aspects of a device, such as the representation of parameter data, or a representation of the functional structure of a device. A sophisticated device model must represent parameter data, device structure and the visual presentation of controls. Parameter data should be related to the device structure, while also being represented within a flexible, logical hierarchy. The development of a standard device model is proposed and discussed with reference to the OSC, IEC62379, ACN and X170 control protocols. This abstract model is independent of any specific control protocol, and provides support for interoperability between control protocols. The proposed model is also discussed within the context of an object-based approach to service enumeration and control using an associative, shared memory model.
- Full Text:
- Date Issued: 2011
When breast is not best: young women and breast reduction surgery
- Lamb, Tessa, Vincent, Louise
- Authors: Lamb, Tessa , Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141832 , vital:38008 , DOI: 10.1080/10130950.2011.610978
- Description: Most cosmetic surgery patients in South Africa are younger than 21, and in this focus we examine narrative accounts from young South African women who have chosen to undergo cosmetic breast reduction surgery. Feminist debates on cosmetic surgery have focused on the question of whether to regard women who modify their bodies in this way as active agents engaged in liberatory ‘body projects’, or whether such projects are evidence of their subjection to oppressive stereotypes and beauty norms. The latter perspective is challenged here by the participants’ characterisation of breast reduction surgery as profoundly ‘freeing’. The article deals in particular with the conscious choice of participants to knowingly risk not being able to breastfeed children in future in order to achieve a body type which conforms to their understanding of youthful beauty and sexuality.
- Full Text:
- Date Issued: 2011
- Authors: Lamb, Tessa , Vincent, Louise
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141832 , vital:38008 , DOI: 10.1080/10130950.2011.610978
- Description: Most cosmetic surgery patients in South Africa are younger than 21, and in this focus we examine narrative accounts from young South African women who have chosen to undergo cosmetic breast reduction surgery. Feminist debates on cosmetic surgery have focused on the question of whether to regard women who modify their bodies in this way as active agents engaged in liberatory ‘body projects’, or whether such projects are evidence of their subjection to oppressive stereotypes and beauty norms. The latter perspective is challenged here by the participants’ characterisation of breast reduction surgery as profoundly ‘freeing’. The article deals in particular with the conscious choice of participants to knowingly risk not being able to breastfeed children in future in order to achieve a body type which conforms to their understanding of youthful beauty and sexuality.
- Full Text:
- Date Issued: 2011
Business Management: BEC 121 & 121E
- Masocha, Reginald, Rungani, Ellen, Puchert, Juliet
- Authors: Masocha, Reginald , Rungani, Ellen , Puchert, Juliet
- Date: 2011-01
- Subjects: Management
- Language: English
- Type: Examination paper
- Identifier: vital:17515 , http://hdl.handle.net/10353/d1011118
- Description: Business Management: BEC 121 & 121E, Supplementary examination January/February 2011.
- Full Text: false
- Date Issued: 2011-01
- Authors: Masocha, Reginald , Rungani, Ellen , Puchert, Juliet
- Date: 2011-01
- Subjects: Management
- Language: English
- Type: Examination paper
- Identifier: vital:17515 , http://hdl.handle.net/10353/d1011118
- Description: Business Management: BEC 121 & 121E, Supplementary examination January/February 2011.
- Full Text: false
- Date Issued: 2011-01
English: ECL 320
- Formson, C, Nyika, N, Morkel, N, Blatchford, M, Scott, R, Makwela, N, Wood, F
- Authors: Formson, C , Nyika, N , Morkel, N , Blatchford, M , Scott, R , Makwela, N , Wood, F
- Date: 2011-01
- Language: English
- Type: Examination paper
- Identifier: vital:18289 , http://hdl.handle.net/10353/d1011295
- Description: English: ECL 320, Supplementary examination January 2011.
- Full Text: false
- Date Issued: 2011-01
- Authors: Formson, C , Nyika, N , Morkel, N , Blatchford, M , Scott, R , Makwela, N , Wood, F
- Date: 2011-01
- Language: English
- Type: Examination paper
- Identifier: vital:18289 , http://hdl.handle.net/10353/d1011295
- Description: English: ECL 320, Supplementary examination January 2011.
- Full Text: false
- Date Issued: 2011-01
Business Mathematics: AMB 111
- Date: 2010-06
- Subjects: Business mathematics
- Language: English
- Type: Examination paper
- Identifier: vital:17471 , http://hdl.handle.net/10353/d1010286
- Description: Business Mathematics: AMB 111, June examination 1st semester 2010.
- Full Text: false
- Date Issued: 2010-06
- Date: 2010-06
- Subjects: Business mathematics
- Language: English
- Type: Examination paper
- Identifier: vital:17471 , http://hdl.handle.net/10353/d1010286
- Description: Business Mathematics: AMB 111, June examination 1st semester 2010.
- Full Text: false
- Date Issued: 2010-06
Interpreting the Text of the Hebrew Bible: THB 211
- Authors: Adolph, E , Oosthuizen, R
- Date: 2010-06
- Language: English
- Type: Examination paper
- Identifier: vital:18152 , http://hdl.handle.net/10353/d1011074
- Description: Interpreting the Text of the Hebrew Bible: THB 211, degree examination June 2010.
- Full Text: false
- Date Issued: 2010-06
- Authors: Adolph, E , Oosthuizen, R
- Date: 2010-06
- Language: English
- Type: Examination paper
- Identifier: vital:18152 , http://hdl.handle.net/10353/d1011074
- Description: Interpreting the Text of the Hebrew Bible: THB 211, degree examination June 2010.
- Full Text: false
- Date Issued: 2010-06
Taxation 3: ATA 311E/ ATV 311E
- Hirschbeck, L, Stevens, N, Olivier, J
- Authors: Hirschbeck, L , Stevens, N , Olivier, J
- Date: 2010-06
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17404 , http://hdl.handle.net/10353/d1009765
- Description: Taxation 3: ATA 311E / ATV 311E, June 2010 Final Examination.
- Full Text:
- Date Issued: 2010-06
- Authors: Hirschbeck, L , Stevens, N , Olivier, J
- Date: 2010-06
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17404 , http://hdl.handle.net/10353/d1009765
- Description: Taxation 3: ATA 311E / ATV 311E, June 2010 Final Examination.
- Full Text:
- Date Issued: 2010-06
Indexes and Abstracts: INF 212
- Chisamatanga, N, Ondari-Okemwa, E M
- Authors: Chisamatanga, N , Ondari-Okemwa, E M
- Date: 2010-04
- Language: English
- Type: Examination paper
- Identifier: vital:17989 , http://hdl.handle.net/10353/d1010563
- Description: Indexes and Abstracts: INF 212, special supplementary examination April 2010.
- Full Text: false
- Date Issued: 2010-04
- Authors: Chisamatanga, N , Ondari-Okemwa, E M
- Date: 2010-04
- Language: English
- Type: Examination paper
- Identifier: vital:17989 , http://hdl.handle.net/10353/d1010563
- Description: Indexes and Abstracts: INF 212, special supplementary examination April 2010.
- Full Text: false
- Date Issued: 2010-04
A histological description of ovarian recrudescence in two Labeo victorianus populations
- Booth, Anthony J, Hecht, Thomas
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123564 , vital:35455 , https://doi.org/10.2989/16085910409503813
- Description: The ovaries of Labeo victorianus are paired organs situated in the peritoneal cavity and suspended on either side of the midline by a mesovarium. A capsule, composed of dense, regularly-arranged collagen and elastic fibres mixed with a few smooth muscle cells, enclosed the ovaries and gave off connective tissue septa, forming the ovigerous lamellae, which contained germ and follicle cells. Eight discrete stages of recrudescence were identified: oogonia, chromatin nucleolar oocytes, perinucleolar oocytes, primary yolk vesicle oocytes, secondary yolk vesicle oocytes, tertiary yolk vesicle oocytes, post-ovulatory follicles and atretic oocytes. Ovulation seemed to be synchronised with the onset of rainfall, with some deviations in the Sio River population. Gonadosomatic index variation followed a bimodal pattern, with maxima between January–February and between September–October for both populations. The same pattern was exhibited for both rainfall and water levels at the two study sites. Successful ovulation was followed by the formation of post-ovulatory follicles and Type I atresia, while failed spawning was characterised by Type II atresia. Clearance of post-ovulatory follicles was by phagocytosis and formation of melanomacrophage centres. There were variations in post-ovulatory changes between the two populations. Reproductive patterns in the Kagera River population conformed to the ‘norm’ in African labeines of the synchronisation of spawning with rainfall. Slight deviations from this pattern were, however, observed in the Sio River population where spawning occurred prior to the onset of rainfall.
- Full Text:
- Date Issued: 2010
- Authors: Booth, Anthony J , Hecht, Thomas
- Date: 2010
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123564 , vital:35455 , https://doi.org/10.2989/16085910409503813
- Description: The ovaries of Labeo victorianus are paired organs situated in the peritoneal cavity and suspended on either side of the midline by a mesovarium. A capsule, composed of dense, regularly-arranged collagen and elastic fibres mixed with a few smooth muscle cells, enclosed the ovaries and gave off connective tissue septa, forming the ovigerous lamellae, which contained germ and follicle cells. Eight discrete stages of recrudescence were identified: oogonia, chromatin nucleolar oocytes, perinucleolar oocytes, primary yolk vesicle oocytes, secondary yolk vesicle oocytes, tertiary yolk vesicle oocytes, post-ovulatory follicles and atretic oocytes. Ovulation seemed to be synchronised with the onset of rainfall, with some deviations in the Sio River population. Gonadosomatic index variation followed a bimodal pattern, with maxima between January–February and between September–October for both populations. The same pattern was exhibited for both rainfall and water levels at the two study sites. Successful ovulation was followed by the formation of post-ovulatory follicles and Type I atresia, while failed spawning was characterised by Type II atresia. Clearance of post-ovulatory follicles was by phagocytosis and formation of melanomacrophage centres. There were variations in post-ovulatory changes between the two populations. Reproductive patterns in the Kagera River population conformed to the ‘norm’ in African labeines of the synchronisation of spawning with rainfall. Slight deviations from this pattern were, however, observed in the Sio River population where spawning occurred prior to the onset of rainfall.
- Full Text:
- Date Issued: 2010