"Should a Vice-Chancellor be a computer scientist?"
- Authors: Henderson, Derek Scott
- Date: 1981
- Language: English
- Type: Text
- Identifier: vital:7432 , http://hdl.handle.net/10962/d1018309
- Description: Information Systems Seminar, Carlton Hotel, Johannesburg, 10 June 1981. Should a Vice-Chancellor be a computer scientist? As I prepared my thoughts to address you this morning it seemed to me that there were three topics of potential interest to this audience on which a person with my background could dwell. 1) Are universities turning out graduates with the right backgrounds (a) to manage companies in which information systems will play an increasingly important role and (b) to drive the information systems effectively? 2) The proper role of the universities in research and development with regard to information systems 3) The effective administrative use of information systems in universities considered as organisations which have as great an obligation to be efficient as businesses.
- Full Text:
- Date Issued: 1981
- Authors: Henderson, Derek Scott
- Date: 1981
- Language: English
- Type: Text
- Identifier: vital:7432 , http://hdl.handle.net/10962/d1018309
- Description: Information Systems Seminar, Carlton Hotel, Johannesburg, 10 June 1981. Should a Vice-Chancellor be a computer scientist? As I prepared my thoughts to address you this morning it seemed to me that there were three topics of potential interest to this audience on which a person with my background could dwell. 1) Are universities turning out graduates with the right backgrounds (a) to manage companies in which information systems will play an increasingly important role and (b) to drive the information systems effectively? 2) The proper role of the universities in research and development with regard to information systems 3) The effective administrative use of information systems in universities considered as organisations which have as great an obligation to be efficient as businesses.
- Full Text:
- Date Issued: 1981
100 years of chemistry at Rhodes University
- Brown, Michael E, Eve, Desmond John, Kaye, Perry T, Rivett, Douglas E A, Watkins, Gareth M
- Authors: Brown, Michael E , Eve, Desmond John , Kaye, Perry T , Rivett, Douglas E A , Watkins, Gareth M
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6564 , http://hdl.handle.net/10962/d1004123
- Description: The history of Grahamstown is well documented and two books deal with the history of Rhodes University.1,2 Although the Chemistry Department was one of the founding departments, coverage in the official histories is minimal and sometimes inaccurate or misleading. The Rhodes University Centenary is an appropriate time to look back on some of the achievements of the department and some of its graduates over the past 100 years.
- Full Text:
- Date Issued: 2004
- Authors: Brown, Michael E , Eve, Desmond John , Kaye, Perry T , Rivett, Douglas E A , Watkins, Gareth M
- Date: 2004
- Language: English
- Type: Article
- Identifier: vital:6564 , http://hdl.handle.net/10962/d1004123
- Description: The history of Grahamstown is well documented and two books deal with the history of Rhodes University.1,2 Although the Chemistry Department was one of the founding departments, coverage in the official histories is minimal and sometimes inaccurate or misleading. The Rhodes University Centenary is an appropriate time to look back on some of the achievements of the department and some of its graduates over the past 100 years.
- Full Text:
- Date Issued: 2004
6th National Congress Resolutions
- Paper, Printing, Wood and Allied Workers' Union (PPWAWU)
- Authors: Paper, Printing, Wood and Allied Workers' Union (PPWAWU)
- Date: Oct 1993
- Subjects: PPWAWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/134779 , vital:37204
- Description: Congress understood well what Cde Nqakula was saying and how important it is to mobilise all our forces to come in with a huge ANC majority in the elections. Delegates made sure through a strong resolution on elections that PPWAWU will play its part: the union will send a fulltime PPWAWU person to COSATU for voter education. This person is Sipho Kubheka and he is already at COSATU head office. One shopsteward from each region will also be released to assist COSATU. Branches must run voter education workshops at once with the education co-ordinator's help. Shopstewards must get time off to train as voter educators, and all workers must give R1 towards voter education.
- Full Text:
- Date Issued: Oct 1993
- Authors: Paper, Printing, Wood and Allied Workers' Union (PPWAWU)
- Date: Oct 1993
- Subjects: PPWAWU
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/134779 , vital:37204
- Description: Congress understood well what Cde Nqakula was saying and how important it is to mobilise all our forces to come in with a huge ANC majority in the elections. Delegates made sure through a strong resolution on elections that PPWAWU will play its part: the union will send a fulltime PPWAWU person to COSATU for voter education. This person is Sipho Kubheka and he is already at COSATU head office. One shopsteward from each region will also be released to assist COSATU. Branches must run voter education workshops at once with the education co-ordinator's help. Shopstewards must get time off to train as voter educators, and all workers must give R1 towards voter education.
- Full Text:
- Date Issued: Oct 1993
A continuous process for the biological treatment of heavy metal contaminated acid mine water
- Van Hille, R P, Boshoff, G A, Rose, P D, Duncan, J R
- Authors: Van Hille, R P , Boshoff, G A , Rose, P D , Duncan, J R
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6464 , http://hdl.handle.net/10962/d1005793 , dx.doi.org/10.1016/S0921-3449(99)00010-5
- Description: Alkaline precipitation of heavy metals from acidic water streams is a popular and long standing treatment process. While this process is efficient it requires the continuous addition of an alkaline material, such as lime. In the long term or when treating large volumes of effluent this process becomes expensive, with costs in the mining sector routinely exceeding millions of rands annually. The process described below utilises alkalinity generated by the alga Spirulina sp., in a continuous system to precipitate heavy metals. The design of the system separates the algal component from the metal containing stream to overcome metal toxicity. The primary treatment process consistently removed over 99% of the iron (98.9 mg/l) and between 80 and 95% of the zinc (7.16 mg/l) and lead (2.35 mg/l) over a 14-day period (20 l effluent treated). In addition the pH of the raw effluent was increased from 1.8 to over 7 in the post-treatment stream. Secondary treatment and polishing steps depend on the nature of the effluent treated. In the case of the high sulphate effluent the treated stream was passed into an anaerobic digester at a rate of 4 l/day. The combination of the primary and secondary treatments effected a removal of over 95% of all metals tested for as well as a 90% reduction in the sulphate load. The running cost of such a process would be low as the salinity and nutrient requirements for the algal culture could be provided by using tannery effluent or a combination of saline water and sewage. This would have the additional benefit of treating either a tannery or sewage effluent as part of an integrated process.
- Full Text:
- Date Issued: 1999
- Authors: Van Hille, R P , Boshoff, G A , Rose, P D , Duncan, J R
- Date: 1999
- Language: English
- Type: Article
- Identifier: vital:6464 , http://hdl.handle.net/10962/d1005793 , dx.doi.org/10.1016/S0921-3449(99)00010-5
- Description: Alkaline precipitation of heavy metals from acidic water streams is a popular and long standing treatment process. While this process is efficient it requires the continuous addition of an alkaline material, such as lime. In the long term or when treating large volumes of effluent this process becomes expensive, with costs in the mining sector routinely exceeding millions of rands annually. The process described below utilises alkalinity generated by the alga Spirulina sp., in a continuous system to precipitate heavy metals. The design of the system separates the algal component from the metal containing stream to overcome metal toxicity. The primary treatment process consistently removed over 99% of the iron (98.9 mg/l) and between 80 and 95% of the zinc (7.16 mg/l) and lead (2.35 mg/l) over a 14-day period (20 l effluent treated). In addition the pH of the raw effluent was increased from 1.8 to over 7 in the post-treatment stream. Secondary treatment and polishing steps depend on the nature of the effluent treated. In the case of the high sulphate effluent the treated stream was passed into an anaerobic digester at a rate of 4 l/day. The combination of the primary and secondary treatments effected a removal of over 95% of all metals tested for as well as a 90% reduction in the sulphate load. The running cost of such a process would be low as the salinity and nutrient requirements for the algal culture could be provided by using tannery effluent or a combination of saline water and sewage. This would have the additional benefit of treating either a tannery or sewage effluent as part of an integrated process.
- Full Text:
- Date Issued: 1999
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
A new Coryogalops species (Pisces: Gobiidae) from South Africa
- Goren, Menachem, J.L.B. Smith Institute of Ichthyology
- Authors: Goren, Menachem , J.L.B. Smith Institute of Ichthyology
- Date: 1991-09
- Subjects: Gobiidae , Fishes -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70922 , vital:29761 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 52 , A new species of gobiid fish, Coryogalops bretti, is described from a single specimen from the Eastern Cape Province of South Africa. The new species is characterized by a continuous oculo-scapular canal with 5 pores above operculum, dorsal fin segmented rays 12; anal fin segmented rays 9; pectoral fin rays 19 (4 upper rays partly free); pectoral fin base scaleless. Body of the holotype black; no dots or bars on fins; black blotch on upper part of pectoral base. The genus Monishia Smith, 1959, is considered a junior synonym of Coryogalops Smith, 1958.
- Full Text:
- Date Issued: 1991-09
- Authors: Goren, Menachem , J.L.B. Smith Institute of Ichthyology
- Date: 1991-09
- Subjects: Gobiidae , Fishes -- South Africa
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70922 , vital:29761 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 52 , A new species of gobiid fish, Coryogalops bretti, is described from a single specimen from the Eastern Cape Province of South Africa. The new species is characterized by a continuous oculo-scapular canal with 5 pores above operculum, dorsal fin segmented rays 12; anal fin segmented rays 9; pectoral fin rays 19 (4 upper rays partly free); pectoral fin base scaleless. Body of the holotype black; no dots or bars on fins; black blotch on upper part of pectoral base. The genus Monishia Smith, 1959, is considered a junior synonym of Coryogalops Smith, 1958.
- Full Text:
- Date Issued: 1991-09
A new species of anthiine fish of the genus Rabaulichthys (Perciformes: Serranidaie) from the Maldive Islands
- Randall, John E, 1924-, Pyle, Robert Michael, J.L.B. Smith Institute of Ichthyology
- Authors: Randall, John E, 1924- , Pyle, Robert Michael , J.L.B. Smith Institute of Ichthyology
- Date: 1989-07
- Subjects: Serranidae -- Maldives
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70313 , vital:29644 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 47 , Rabaulichthys stigmaticus is described as a new species of serranid fish of the subfamily Anthiinae from four male specimens collected in 35 m on a rubble bottom off Ari Aroll in the Republic of Maldives, it is distinct from the only other known species of the genus, R. altipinnis Allen from New Britain, in having a longer snout (6.7-7.1%SL, versus 5.5-6.4%SL), a higher dorsal fin in the adult male (30-39% SL), a large quadrangular dark spot on the side of the body above the anal fin, and an elongate black blotch in the soft portion of the dorsal fin. Specimens of a possible third species taken in a dredge at Condor Reef, Caroline Islands are discussed.
- Full Text:
- Date Issued: 1989-07
- Authors: Randall, John E, 1924- , Pyle, Robert Michael , J.L.B. Smith Institute of Ichthyology
- Date: 1989-07
- Subjects: Serranidae -- Maldives
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/70313 , vital:29644 , Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB)) Periodicals Margaret Smith Library (South African Institute for Aquatic Biodiversity (SAIAB))
- Description: Online version of original print edition of the Special Publication of the J.L.B. Smith Institute of Ichthyology; No. 47 , Rabaulichthys stigmaticus is described as a new species of serranid fish of the subfamily Anthiinae from four male specimens collected in 35 m on a rubble bottom off Ari Aroll in the Republic of Maldives, it is distinct from the only other known species of the genus, R. altipinnis Allen from New Britain, in having a longer snout (6.7-7.1%SL, versus 5.5-6.4%SL), a higher dorsal fin in the adult male (30-39% SL), a large quadrangular dark spot on the side of the body above the anal fin, and an elongate black blotch in the soft portion of the dorsal fin. Specimens of a possible third species taken in a dredge at Condor Reef, Caroline Islands are discussed.
- Full Text:
- Date Issued: 1989-07
A strategic perspective - Negotiations
- ANC
- Authors: ANC
- Date: Nov 1992
- Subjects: African National Congress (ANC)
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/149099 , vital:38804
- Full Text:
- Date Issued: Nov 1992
- Authors: ANC
- Date: Nov 1992
- Subjects: African National Congress (ANC)
- Language: English
- Type: text
- Identifier: http://hdl.handle.net/10962/149099 , vital:38804
- Full Text:
- Date Issued: Nov 1992
Academic literacy and the decontextualised learner
- Boughey, Chrissie, McKenna, Sioux
- Authors: Boughey, Chrissie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64651 , vital:28585 , http://www.DOI:10.14426/cristal.v4i2.80
- Description: The literacy practices that are valued in the university emerge from specific disciplinary histories yet students are often expected to master these as if they were common sense and natural. This article argues that the autonomous model of literacy, which sees language use as the application of a set of neutral skills, continues to dominate in South African universities. This model denies the extent to which taking on disciplinary literacy practices can be difficult and have implications for identity. It also allows disciplinary norms to remain largely opaque and beyond critique. Furthermore, the autonomous model of literacy is often coupled with a discourse of the ‘decontextualised learner’ who is divorced from her social context, with higher education success seen to be resting largely upon attributes inherent in, or lacking from, the individual. Sadly, alternative critical social understandings have not been widely taken up despite their being well researched. Indeed, such understandings have often been misappropriated in ways that draw on critical social terminology to offer autonomous, decontextualised, remedial student interventions. We argue that these issues are implicated in students’ accusations that universities are alienating spaces.
- Full Text:
- Date Issued: 2016
- Authors: Boughey, Chrissie , McKenna, Sioux
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/64651 , vital:28585 , http://www.DOI:10.14426/cristal.v4i2.80
- Description: The literacy practices that are valued in the university emerge from specific disciplinary histories yet students are often expected to master these as if they were common sense and natural. This article argues that the autonomous model of literacy, which sees language use as the application of a set of neutral skills, continues to dominate in South African universities. This model denies the extent to which taking on disciplinary literacy practices can be difficult and have implications for identity. It also allows disciplinary norms to remain largely opaque and beyond critique. Furthermore, the autonomous model of literacy is often coupled with a discourse of the ‘decontextualised learner’ who is divorced from her social context, with higher education success seen to be resting largely upon attributes inherent in, or lacking from, the individual. Sadly, alternative critical social understandings have not been widely taken up despite their being well researched. Indeed, such understandings have often been misappropriated in ways that draw on critical social terminology to offer autonomous, decontextualised, remedial student interventions. We argue that these issues are implicated in students’ accusations that universities are alienating spaces.
- Full Text:
- Date Issued: 2016
Academic Practices and Reasoning: APR 111
- Authors: Scott, R , Blatchford, M
- Date: 2011-07
- Language: English
- Type: Examination paper
- Identifier: vital:18261 , http://hdl.handle.net/10353/d1011257
- Description: Academic Practices and Reasoning: APR 111, examination July/August 2011.
- Full Text: false
- Date Issued: 2011-07
- Authors: Scott, R , Blatchford, M
- Date: 2011-07
- Language: English
- Type: Examination paper
- Identifier: vital:18261 , http://hdl.handle.net/10353/d1011257
- Description: Academic Practices and Reasoning: APR 111, examination July/August 2011.
- Full Text: false
- Date Issued: 2011-07
Accounting 1: AFA 112
- Authors: Nobuya, X , Mnconywa, N
- Date: 2011-06
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17420 , http://hdl.handle.net/10353/d1009789
- Description: Accounting 1: AFA 112, June 2011, Supplementary examination.
- Full Text: false
- Date Issued: 2011-06
- Authors: Nobuya, X , Mnconywa, N
- Date: 2011-06
- Subjects: Accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17420 , http://hdl.handle.net/10353/d1009789
- Description: Accounting 1: AFA 112, June 2011, Supplementary examination.
- Full Text: false
- Date Issued: 2011-06
Accuracy and reproducibility of the multiple-reading skin blanching assay
- Smith, Eric W, Meyer, Eric, Haigh, John M
- Authors: Smith, Eric W , Meyer, Eric , Haigh, John M
- Date: 1992
- Language: English
- Type: Book chapter
- Identifier: vital:6439 , http://hdl.handle.net/10962/d1006625
- Full Text:
- Date Issued: 1992
- Authors: Smith, Eric W , Meyer, Eric , Haigh, John M
- Date: 1992
- Language: English
- Type: Book chapter
- Identifier: vital:6439 , http://hdl.handle.net/10962/d1006625
- Full Text:
- Date Issued: 1992
An analysis of the influence of question design on learners' approaches to number pattern generalisation tasks:
- Samson, Duncan, Schäfer, Marc
- Authors: Samson, Duncan , Schäfer, Marc
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141026 , vital:37938 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC20890
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2007
- Authors: Samson, Duncan , Schäfer, Marc
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141026 , vital:37938 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC20890
- Description: This paper reports on a study of the extent to which question design affects the solution strategies adopted by children when solving linear number pattern generalisation tasks presented in pictorial and numeric contexts. The research tool comprised a series of 22 pencil-and-paper exercises based on linear generalisation tasks set in both numeric and two-dimensional pictorial contexts. The responses to these linear generalisation questions were classified by means of stage descriptors as well as stage modifiers. The method or strategy adopted was analysed and classified into one of seven categories. In addition, a meta-analysis focused on the formula derived for the nth term in conjunction with its justification. The results of this study strongly support the notion that question design can play a critical role in influencing learners' choice of strategy and level of attainment when solving pattern generalisation tasks. An understanding of the importance of appropriate question design has direct pedagogical application within the context of the mathematics classroom.
- Full Text:
- Date Issued: 2007
Anomalous behaviour of thermoluminescence from quartz: a case of glow peaks from a Nigerian quartz
- Ogundare, F O, Chithambo, Makaiko L, Oniya, E O
- Authors: Ogundare, F O , Chithambo, Makaiko L , Oniya, E O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6796 , http://hdl.handle.net/10962/d1003922
- Description: Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ºC for the sample readout at a heating rate of 1ºCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ºC for a sample irradiated to a dose of 63 Gy and heated at 1ºCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ºC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.
- Full Text:
- Date Issued: 2006
- Authors: Ogundare, F O , Chithambo, Makaiko L , Oniya, E O
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6796 , http://hdl.handle.net/10962/d1003922
- Description: Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ºC for the sample readout at a heating rate of 1ºCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ºC for a sample irradiated to a dose of 63 Gy and heated at 1ºCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ºC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour.
- Full Text:
- Date Issued: 2006
Anti-staphylococcal, anti-HIV and cytotoxicity studies of four South African medicinal plants and isolation of bioactive compounds from Cassine transvaalensis (Burtt. Davy) codd
- Mthethwa, Ningy S, Oyedeji, Bola A O, Obi, Larry C, Aiyegoro, Olayinka A
- Authors: Mthethwa, Ningy S , Oyedeji, Bola A O , Obi, Larry C , Aiyegoro, Olayinka A
- Date: 2014
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/722 , vital:29661
- Description: Background: Medicinal plants represent an important opportunity to rural communities in Africa, as a source of affordable medicine and as a source of income. Increased patient awareness about safe usage is important as well as more training with regards to traditional medicine. The aim of this study was to evaluate the ethnomedicinal prowess of some indigenous South African plants commonly used in Eastern Cape Province of South Africa for the treatment of skin and respiratory tract infections, HIV and their toxicity potential. Methods: Cassine transvaalensis, Vangueria infausta, Croton gratissimus and Vitex ferruginea were tested for antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis using Kirby-Bauer disk diffusion and minimum inhibition concentration (MIC). Cytotoxic and anti-HIV-1 activities of plants were tested using MTT Assay (3- (Dimethylthiozole-2-yl-2,5-diphenyltetrazolium bromide)) and anti- HIV-1iib assay. In search of bioactive lead compounds, Cassine transvaalensis which was found to be the most active plant extract against the two Staphylocoous bacteria was subjected to various chromatographic. Thin layer chromatography, Column chromatography and Nuclear Magnetic Resonance (NMR), (1H-1H, 13C-13C, in DMSO_d6, Bruker 600 MHz) were used to isolate and characterize 3-Oxo-28-hydroxylbetuli-20(29)-ene and 3,28-dihydroxylbetuli-20(29)-ene bioactive compounds from C. transvaalensis. Results: The four plants studied exhibited bioactive properties against the test isolates. The zones of inhibition rangedbetween 16 mm to 31 mm for multi-drug resistant staphylococci species. MIC values varied between 0.6 and 0.02 μg/ml. C. gratissimus and C. transvaalensis exhibited the abilities to inhibit HIV-1iib. Two bioactive compounds were isolated from C. transvaalensis. Conclusion: Data from this study reveals the use of these plant by traditional healers in the Eastern Cape. Furthermore, C. transvaalensis and C. gratissimus were found to be more active as against HIV-1iib. While C. transvaalensis was most active against the two Staphylococcus bacteria.
- Full Text:
- Date Issued: 2014
- Authors: Mthethwa, Ningy S , Oyedeji, Bola A O , Obi, Larry C , Aiyegoro, Olayinka A
- Date: 2014
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/722 , vital:29661
- Description: Background: Medicinal plants represent an important opportunity to rural communities in Africa, as a source of affordable medicine and as a source of income. Increased patient awareness about safe usage is important as well as more training with regards to traditional medicine. The aim of this study was to evaluate the ethnomedicinal prowess of some indigenous South African plants commonly used in Eastern Cape Province of South Africa for the treatment of skin and respiratory tract infections, HIV and their toxicity potential. Methods: Cassine transvaalensis, Vangueria infausta, Croton gratissimus and Vitex ferruginea were tested for antibacterial activities against Staphylococcus aureus and Staphylococcus epidermidis using Kirby-Bauer disk diffusion and minimum inhibition concentration (MIC). Cytotoxic and anti-HIV-1 activities of plants were tested using MTT Assay (3- (Dimethylthiozole-2-yl-2,5-diphenyltetrazolium bromide)) and anti- HIV-1iib assay. In search of bioactive lead compounds, Cassine transvaalensis which was found to be the most active plant extract against the two Staphylocoous bacteria was subjected to various chromatographic. Thin layer chromatography, Column chromatography and Nuclear Magnetic Resonance (NMR), (1H-1H, 13C-13C, in DMSO_d6, Bruker 600 MHz) were used to isolate and characterize 3-Oxo-28-hydroxylbetuli-20(29)-ene and 3,28-dihydroxylbetuli-20(29)-ene bioactive compounds from C. transvaalensis. Results: The four plants studied exhibited bioactive properties against the test isolates. The zones of inhibition rangedbetween 16 mm to 31 mm for multi-drug resistant staphylococci species. MIC values varied between 0.6 and 0.02 μg/ml. C. gratissimus and C. transvaalensis exhibited the abilities to inhibit HIV-1iib. Two bioactive compounds were isolated from C. transvaalensis. Conclusion: Data from this study reveals the use of these plant by traditional healers in the Eastern Cape. Furthermore, C. transvaalensis and C. gratissimus were found to be more active as against HIV-1iib. While C. transvaalensis was most active against the two Staphylococcus bacteria.
- Full Text:
- Date Issued: 2014
Antiviral drug discovery: preparing for the next pandemic
- Adamson, Catherine S, Chibale, Kelly, Goss, Rebecca J M, Jaspars, Marcel, Newman, David J, Dorrington, Rosemary A
- Authors: Adamson, Catherine S , Chibale, Kelly , Goss, Rebecca J M , Jaspars, Marcel , Newman, David J , Dorrington, Rosemary A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177499 , vital:42827 , DOI: 10.1039/d0cs01118e
- Description: Clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. The SARS-CoV-2 outbreak has exposed the critical need for compounds that can be rapidly mobilised for the treatment of re-emerging or emerging viral diseases, while vaccine development is underway. We review the current status of antiviral therapies focusing on RNA viruses, highlighting strategies for antiviral drug discovery and discuss the challenges, solutions and options to accelerate drug discovery efforts.
- Full Text:
- Date Issued: 2021
- Authors: Adamson, Catherine S , Chibale, Kelly , Goss, Rebecca J M , Jaspars, Marcel , Newman, David J , Dorrington, Rosemary A
- Date: 2021
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/177499 , vital:42827 , DOI: 10.1039/d0cs01118e
- Description: Clinically approved antiviral drugs are currently available for only 10 of the more than 220 viruses known to infect humans. The SARS-CoV-2 outbreak has exposed the critical need for compounds that can be rapidly mobilised for the treatment of re-emerging or emerging viral diseases, while vaccine development is underway. We review the current status of antiviral therapies focusing on RNA viruses, highlighting strategies for antiviral drug discovery and discuss the challenges, solutions and options to accelerate drug discovery efforts.
- Full Text:
- Date Issued: 2021
Application of quality by design principles for optimizing process variables of Extrusion and Spheronization of a Captopril Pellet Formulation:
- Veerubhotla, Krishna, Walker, Roderick B
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
- Authors: Veerubhotla, Krishna , Walker, Roderick B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/178312 , vital:40098 , DOI: 10.36468/pharmaceutical-sciences.624
- Description: Product development using quality by design is a proactive and risk-based approach that shifts the manufacturing process from empirical to science-based. Risk assessment was performed to identify and analyse risk areas for the manufacture of captopril pellets. Twelve experimental runs were performed using a Plackett-Burman screening design. Pareto plots revealed the effect of formulation and process variables on the responses monitored and facilitated the identification of the most critical parameters for optimization of the formulation. A response surface methodology approach in conjunction with a central composite design was used to optimize the Eudragit® RL 30D (15-30 ml), microcrystalline cellulose (20-40 % w/w), sodium starch glycolate (2-5 % w/w) and spheronizer speed (650-1050 rpm).
- Full Text:
- Date Issued: 2020
Application of satellite-derived rainfall estimates to extend water resource simulation modelling in South Africa
- Sawunyama, Tendai, Hughes, Denis A
- Authors: Sawunyama, Tendai , Hughes, Denis A
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7089 , http://hdl.handle.net/10962/d1012419
- Description: Spatially interpolated rainfall estimates from rain-gauges are widely used as input to hydrological models, but deriving accurate estimates at appropriate space and time scales remain a major problem. In South Africa there has been a gradual decrease in the number of active rain-gauges over time. Satellite-based estimates of spatial rainfall are becoming more readily available and offer a viable substitute. The paper presents the potential of using Climate Prediction Center African daily precipitation climatology (CPCAPC) satellite-based datasets (2001-2006) to drive a Pitman hydrological model which has been calibrated using gauge-based rainfall data (1920-1990). However, if two sources of rainfall data are to be used together, it is necessary to ensure that they are compatible in terms of their statistical properties. A non-linear frequency of exceedance transformation technique was used to correct the satellite data to be more consistent with historical spatial rainfall estimates. The technique generated simulation results for the 2001 to 2006 period that were greatly improved compared to the direct use of the untransformed satellite data. While there remain some further questions about the use of satellite-derived rainfall data in different parts of the country, they do seem to have the potential to contribute to extending water resource modelling into the future.
- Full Text:
- Date Issued: 2008
- Authors: Sawunyama, Tendai , Hughes, Denis A
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7089 , http://hdl.handle.net/10962/d1012419
- Description: Spatially interpolated rainfall estimates from rain-gauges are widely used as input to hydrological models, but deriving accurate estimates at appropriate space and time scales remain a major problem. In South Africa there has been a gradual decrease in the number of active rain-gauges over time. Satellite-based estimates of spatial rainfall are becoming more readily available and offer a viable substitute. The paper presents the potential of using Climate Prediction Center African daily precipitation climatology (CPCAPC) satellite-based datasets (2001-2006) to drive a Pitman hydrological model which has been calibrated using gauge-based rainfall data (1920-1990). However, if two sources of rainfall data are to be used together, it is necessary to ensure that they are compatible in terms of their statistical properties. A non-linear frequency of exceedance transformation technique was used to correct the satellite data to be more consistent with historical spatial rainfall estimates. The technique generated simulation results for the 2001 to 2006 period that were greatly improved compared to the direct use of the untransformed satellite data. While there remain some further questions about the use of satellite-derived rainfall data in different parts of the country, they do seem to have the potential to contribute to extending water resource modelling into the future.
- Full Text:
- Date Issued: 2008
Application of the Minolta chromameter to the assessment of corticosteroid-induced skin blanching
- Walker, Roderick B, Haigh, John M, Smith, Eric W
- Authors: Walker, Roderick B , Haigh, John M , Smith, Eric W
- Date: 2000
- Language: English
- Type: Book chapter , text
- Identifier: vital:6451 , http://hdl.handle.net/10962/d1006639
- Full Text:
- Date Issued: 2000
- Authors: Walker, Roderick B , Haigh, John M , Smith, Eric W
- Date: 2000
- Language: English
- Type: Book chapter , text
- Identifier: vital:6451 , http://hdl.handle.net/10962/d1006639
- Full Text:
- Date Issued: 2000
Aspects of the biology and life history of largespot pompano, Trachinotus botla, in South Africa
- Parker, Daniel, Booth, Anthony J
- Authors: Parker, Daniel , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123798 , vital:35499 , https://doi.10.1071/MF14029
- Description: Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of, 7 years. Males and females sexually matured in their third year. It has a protracted summer spawning season with evidence of serial spawning behaviour. T. botla is an opportunistic predator with a generalist diet, with fish feeding on a wide variety of prey items particularly those that are temporally ‘superabundant’. Small fish fed predominantly on copepods and terrestrial insects, whereas larger fish consumed bivalves and crabs. Teleosts, primarily engraulids, were important components to the diet of fish of all sizes. An ontogenetic dietary shift was observed just after sexual maturity (300-mm fork length) that is possibly linked to a change in habitat preference with larger fish foraging on deeper reefs.
- Full Text:
- Date Issued: 2015
- Authors: Parker, Daniel , Booth, Anthony J
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123798 , vital:35499 , https://doi.10.1071/MF14029
- Description: Trachinotus botla is an important recreational surf zone-dependent fish species distributed in the Indo-west Pacific from South Africa to Australia. In South Africa it is restricted to the northern KwaZulu-Natal coast. Biological investigations revealed that it is a fast growing species that attains a maximum age of, 7 years. Males and females sexually matured in their third year. It has a protracted summer spawning season with evidence of serial spawning behaviour. T. botla is an opportunistic predator with a generalist diet, with fish feeding on a wide variety of prey items particularly those that are temporally ‘superabundant’. Small fish fed predominantly on copepods and terrestrial insects, whereas larger fish consumed bivalves and crabs. Teleosts, primarily engraulids, were important components to the diet of fish of all sizes. An ontogenetic dietary shift was observed just after sexual maturity (300-mm fork length) that is possibly linked to a change in habitat preference with larger fish foraging on deeper reefs.
- Full Text:
- Date Issued: 2015