A few points on Pointfree pseudocompactness
- Authors: Dube, T , Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6783 , http://hdl.handle.net/10962/d1006926
- Description: We present several characterizations of completely regular pseudocompact frames. The first is an extension to frames of characterizations of completely regular pseudocompact spaces given by Väänänen. We follow with an embedding-type characterization stating that a completely regular frame is pseudocompact if and only if it is a P-quotient of its Stone-Čech compactification. We then give a characterization in terms of ideals in the cozero parts of the frames concerned. This characterization seems to be new and its spatial counterpart does not seem to have been observed before. We also define relatively pseudocompact quotients, and show that a necessary and sufficient condition for a completely regular frame to be pseudocompact is that it be relatively pseudocompact in its Hewitt realcompactification. Consequently a proof of a result of Banaschewski and Gilmour that a completely regular frame is pseudocompact if and only if its Hewitt realcompactification is compact, is presented without the invocation of the Boolean Ultrafilter Theorem.
- Full Text:
- Date Issued: 2007
- Authors: Dube, T , Matutu, Phethiwe P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6783 , http://hdl.handle.net/10962/d1006926
- Description: We present several characterizations of completely regular pseudocompact frames. The first is an extension to frames of characterizations of completely regular pseudocompact spaces given by Väänänen. We follow with an embedding-type characterization stating that a completely regular frame is pseudocompact if and only if it is a P-quotient of its Stone-Čech compactification. We then give a characterization in terms of ideals in the cozero parts of the frames concerned. This characterization seems to be new and its spatial counterpart does not seem to have been observed before. We also define relatively pseudocompact quotients, and show that a necessary and sufficient condition for a completely regular frame to be pseudocompact is that it be relatively pseudocompact in its Hewitt realcompactification. Consequently a proof of a result of Banaschewski and Gilmour that a completely regular frame is pseudocompact if and only if its Hewitt realcompactification is compact, is presented without the invocation of the Boolean Ultrafilter Theorem.
- Full Text:
- Date Issued: 2007
A fuzzy classification technique for predicting species' distributions: applications using invasive alien plants and indigenous insects
- Robertson, Mark P, Villet, Martin H, Palmer, Anthony R
- Authors: Robertson, Mark P , Villet, Martin H , Palmer, Anthony R
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6897 , http://hdl.handle.net/10962/d1011659 , http://dx.doi.org/10.1111/j.1366-9516.2004.00108.x
- Description: A new predictive modelling technique called the fuzzy envelope model (FEM) is introduced. The technique can be used to predict potential distributions of organisms using presence-only locality records and a set of environmental predictor variables. FEM uses fuzzy logic to classify a set of predictor variable maps based on the values associated with presence records and combines the results to produce a potential distribution map for a target species. This technique represents several refinements of the envelope approach used in the BIOCLIM modelling package. These refinements are related to the way in which FEMs deal with uncertainty, the way in which this uncertainty is represented in the resultant potential distribution maps, and the way that these maps can be interpreted and applied. To illustrate its potential use in biogeographical studies, FEM was applied to predicting the potential distribution of three invasive alien plant species (Lantana camara L., Ricinus communis L. and Solanum mauritianum Scop.), and three native cicada species (Capicada decora Germar, Platypleura deusta Thun. and P. capensis L.) in South Africa, Lesotho and Swaziland. These models were quantitatively compared with models produced by means of the algorithm used in the BIOCLIM modelling package, which is referred to as a crisp envelope model (the CEM design). The average performance of models of the FEM design was consistently higher than those of the CEM design. There were significant differences in model performance among species but there was no significant interaction between model design and species. The average maximum kappa value ranged from 0.70 to 0.90 for FEM design and from 0.57 to 0.89 for the CEM design, which can be described as 'good' to 'excellent' using published ranges of agreement for the kappa statistic. This technique can be used to predict species' potential distributions that could be used for identifying regions at risk from invasion by alien species. These predictions could also be used in conservation planning in the case of native species.
- Full Text:
- Date Issued: 2004
- Authors: Robertson, Mark P , Villet, Martin H , Palmer, Anthony R
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6897 , http://hdl.handle.net/10962/d1011659 , http://dx.doi.org/10.1111/j.1366-9516.2004.00108.x
- Description: A new predictive modelling technique called the fuzzy envelope model (FEM) is introduced. The technique can be used to predict potential distributions of organisms using presence-only locality records and a set of environmental predictor variables. FEM uses fuzzy logic to classify a set of predictor variable maps based on the values associated with presence records and combines the results to produce a potential distribution map for a target species. This technique represents several refinements of the envelope approach used in the BIOCLIM modelling package. These refinements are related to the way in which FEMs deal with uncertainty, the way in which this uncertainty is represented in the resultant potential distribution maps, and the way that these maps can be interpreted and applied. To illustrate its potential use in biogeographical studies, FEM was applied to predicting the potential distribution of three invasive alien plant species (Lantana camara L., Ricinus communis L. and Solanum mauritianum Scop.), and three native cicada species (Capicada decora Germar, Platypleura deusta Thun. and P. capensis L.) in South Africa, Lesotho and Swaziland. These models were quantitatively compared with models produced by means of the algorithm used in the BIOCLIM modelling package, which is referred to as a crisp envelope model (the CEM design). The average performance of models of the FEM design was consistently higher than those of the CEM design. There were significant differences in model performance among species but there was no significant interaction between model design and species. The average maximum kappa value ranged from 0.70 to 0.90 for FEM design and from 0.57 to 0.89 for the CEM design, which can be described as 'good' to 'excellent' using published ranges of agreement for the kappa statistic. This technique can be used to predict species' potential distributions that could be used for identifying regions at risk from invasion by alien species. These predictions could also be used in conservation planning in the case of native species.
- Full Text:
- Date Issued: 2004
A gala night for Sponono
- Authors: Musi, Obed
- Language: English
- Type: Article
- Identifier: vital:13615 , http://hdl.handle.net/10962/d1012485
- Description: Photocopied article from the South African newspaper The World about a gala concert for Sponono Choir with Chris McGregor, Letta Mbuli, Dube and Dunkeld. A picture of Chris McGregor playing piano is also accompanying this article.
- Full Text:
- Authors: Musi, Obed
- Language: English
- Type: Article
- Identifier: vital:13615 , http://hdl.handle.net/10962/d1012485
- Description: Photocopied article from the South African newspaper The World about a gala concert for Sponono Choir with Chris McGregor, Letta Mbuli, Dube and Dunkeld. A picture of Chris McGregor playing piano is also accompanying this article.
- Full Text:
A generic database and spatial interface for the application of hydrological and water resource models
- Hughes, Denis A, Forsyth, D A
- Authors: Hughes, Denis A , Forsyth, D A
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7080 , http://hdl.handle.net/10962/d1012333
- Description: The paper discusses a software package that has been designed to enhance the efficiency of applying a range of hydrological and water resource simulation models. The SPATSIM (SPatial and Time Series Information Modeling) system has been developed in Delphi using MapObjects and incorporates a spatial data interface for access to the different types of information commonly associated with water resource analyses. All of the information is stored within database tables (Paradox by default) with generic structures. The structure and components of the system are briefly described and some example applications provided. The discussion identifies some of the criticisms that have been leveled at the software, the approach of the developers to user support and some possible future developments. The conclusions suggest that the development can be considered successful in that it has substantially improved the efficiency of the Institute for Water Research to undertake one of its core functions of hydrological model development and application.
- Full Text:
- Date Issued: 2006
- Authors: Hughes, Denis A , Forsyth, D A
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:7080 , http://hdl.handle.net/10962/d1012333
- Description: The paper discusses a software package that has been designed to enhance the efficiency of applying a range of hydrological and water resource simulation models. The SPATSIM (SPatial and Time Series Information Modeling) system has been developed in Delphi using MapObjects and incorporates a spatial data interface for access to the different types of information commonly associated with water resource analyses. All of the information is stored within database tables (Paradox by default) with generic structures. The structure and components of the system are briefly described and some example applications provided. The discussion identifies some of the criticisms that have been leveled at the software, the approach of the developers to user support and some possible future developments. The conclusions suggest that the development can be considered successful in that it has substantially improved the efficiency of the Institute for Water Research to undertake one of its core functions of hydrological model development and application.
- Full Text:
- Date Issued: 2006
A Geographic Information System for the African Coelacanth Ecosystem Programme
- Authors: Scott, Lucy E P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:7129 , http://hdl.handle.net/10962/d1010639
- Description: The African Coelacanth Ecosystem Programme (ACEP) Geographic Information System (GIS) has been developed to integrate, analyse and map all spatial data generated within the ACEP programme. A GIS is a multidisciplinary tool, and within ACEP the GIS has been used to integrate information from marine biology studies, oceanographic surveys, geophysical exploration as well as the observations made and footage taken from a research submersible. The core data in the GIS are based on deep marine ecosystems and the programme’s flagship species, Latimeria chalumnae (the coelacanth). Over and above the utility of the GIS as a tool for science through its considerable information storage, analysis and display capabilities, the ACEP GIS has been used for interactive environmental education purposes and to generate public awareness of the programme at various meetings, training events and conferences.
- Full Text:
- Date Issued: 2006
- Authors: Scott, Lucy E P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:7129 , http://hdl.handle.net/10962/d1010639
- Description: The African Coelacanth Ecosystem Programme (ACEP) Geographic Information System (GIS) has been developed to integrate, analyse and map all spatial data generated within the ACEP programme. A GIS is a multidisciplinary tool, and within ACEP the GIS has been used to integrate information from marine biology studies, oceanographic surveys, geophysical exploration as well as the observations made and footage taken from a research submersible. The core data in the GIS are based on deep marine ecosystems and the programme’s flagship species, Latimeria chalumnae (the coelacanth). Over and above the utility of the GIS as a tool for science through its considerable information storage, analysis and display capabilities, the ACEP GIS has been used for interactive environmental education purposes and to generate public awareness of the programme at various meetings, training events and conferences.
- Full Text:
- Date Issued: 2006
A Geographic Information System for the African Coelacanth Ecosystem Programme
- Authors: Scott, Lucy E P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:7159 , http://hdl.handle.net/10962/d1011886
- Description: The African Coelacanth Ecosystem Programme (ACEP) Geographic Information System (GIS) has been developed to integrate, analyse and map all spatial data generated within the ACEP programme. A GIS is a multidisciplinary tool, and within ACEP the GIS has been used to integrate information from marine biology studies, oceanographic surveys, geophysical exploration as well as the observations made and footage taken from a research submersible. The core data in the GIS are based on deep marine ecosystems and the programme’s flagship species, Latimeria chalumnae (the coelacanth). Over and above the utility of the GIS as a tool for science through its considerable information storage, analysis and display capabilities, the ACEP GIS has been used for interactive environmental education purposes and to generate public awareness of the programme at various meetings, training events and conferences.
- Full Text:
- Date Issued: 2006
- Authors: Scott, Lucy E P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:7159 , http://hdl.handle.net/10962/d1011886
- Description: The African Coelacanth Ecosystem Programme (ACEP) Geographic Information System (GIS) has been developed to integrate, analyse and map all spatial data generated within the ACEP programme. A GIS is a multidisciplinary tool, and within ACEP the GIS has been used to integrate information from marine biology studies, oceanographic surveys, geophysical exploration as well as the observations made and footage taken from a research submersible. The core data in the GIS are based on deep marine ecosystems and the programme’s flagship species, Latimeria chalumnae (the coelacanth). Over and above the utility of the GIS as a tool for science through its considerable information storage, analysis and display capabilities, the ACEP GIS has been used for interactive environmental education purposes and to generate public awareness of the programme at various meetings, training events and conferences.
- Full Text:
- Date Issued: 2006
A global study of forensically significant calliphorids: implications for identification
- Harvey, M L, Gaudieri, S, Villet, Martin H, Dadour, I R
- Authors: Harvey, M L , Gaudieri, S , Villet, Martin H , Dadour, I R
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6863 , http://hdl.handle.net/10962/d1011156
- Description: A proliferation of molecular studies of the forensically significant Calliphoridae in the last decade has seen molecule-based identification of immature and damaged specimens become a routine complement to traditional morphological identification as a preliminary to the accurate estimation of post-mortem intervals (PMI), which depends on the use of species-specific developmental data. Published molecular studies have tended to focus on generating data for geographically localised communities of species of importance, which has limited the consideration of intraspecific variation in species of global distribution. This study used phylogenetic analysis to assess the species status of 27 forensically important calliphorid species based on 1167 base pairs of the COI gene of 119 specimens from 22 countries, and confirmed the utility of the COI gene in identifying most species. The species Lucilia cuprina, Chrysomya megacephala, Ch. saffranea, Ch. albifrontalis and Calliphora stygia were unable to be monophyletically resolved based on these data. Identification of phylogenetically young species will require a faster-evolving molecular marker, but most species could be unambiguously characterised by sampling relatively few conspecific individuals if they were from distant localities. Intraspecific geographical variation was observed within Ch. rufifacies and L. cuprina, and is discussed with reference to unrecognised species.
- Full Text:
- Date Issued: 2008
- Authors: Harvey, M L , Gaudieri, S , Villet, Martin H , Dadour, I R
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:6863 , http://hdl.handle.net/10962/d1011156
- Description: A proliferation of molecular studies of the forensically significant Calliphoridae in the last decade has seen molecule-based identification of immature and damaged specimens become a routine complement to traditional morphological identification as a preliminary to the accurate estimation of post-mortem intervals (PMI), which depends on the use of species-specific developmental data. Published molecular studies have tended to focus on generating data for geographically localised communities of species of importance, which has limited the consideration of intraspecific variation in species of global distribution. This study used phylogenetic analysis to assess the species status of 27 forensically important calliphorid species based on 1167 base pairs of the COI gene of 119 specimens from 22 countries, and confirmed the utility of the COI gene in identifying most species. The species Lucilia cuprina, Chrysomya megacephala, Ch. saffranea, Ch. albifrontalis and Calliphora stygia were unable to be monophyletically resolved based on these data. Identification of phylogenetically young species will require a faster-evolving molecular marker, but most species could be unambiguously characterised by sampling relatively few conspecific individuals if they were from distant localities. Intraspecific geographical variation was observed within Ch. rufifacies and L. cuprina, and is discussed with reference to unrecognised species.
- Full Text:
- Date Issued: 2008
A Herefordshire life : the life and times of Leslie Evans, bell ringer, musician, craftsman and countryman : book review
- Authors: Lewis, Colin A
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6171 , http://hdl.handle.net/10962/d1012362 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2006
- Authors: Lewis, Colin A
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6171 , http://hdl.handle.net/10962/d1012362 , http://www.ringingworld.co.uk
- Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2006
A history of southern African research relevant to forensic entomology
- Williams, K A, Villet, Martin H
- Authors: Williams, K A , Villet, Martin H
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6909 , http://hdl.handle.net/10962/d1011862
- Description: Entomological forensic evidence has been used in southern Africa for decades but explicitly forensic research began in southern Africa only 26 years ago. Although applicable local research has accumulated since 1921, it is scattered in a diverse literature or unpublished. Some overseas research has also touched on local species. This review uses a historical approach to synthesize the southern African literature and to illustrate the cross-disciplinary, opportunistic nature of forensic entomology. Distinct phases of research focused on agriculture (1921-1950), medicine (1952- 1965), ecology (1968-1990) and forensics (1980-2005), but systematics spanned the entire period and tended to be ad hoc. Few scientists were involved, situated at geographically distant locations and with widely disparate research interests. The review concludes with an overview of southern African entomologists who have been involved in medico-legal investigations, and a critical evaluation of the past and future of the discipline locally.
- Full Text:
- Date Issued: 2006
- Authors: Williams, K A , Villet, Martin H
- Date: 2006
- Language: English
- Type: text , Article
- Identifier: vital:6909 , http://hdl.handle.net/10962/d1011862
- Description: Entomological forensic evidence has been used in southern Africa for decades but explicitly forensic research began in southern Africa only 26 years ago. Although applicable local research has accumulated since 1921, it is scattered in a diverse literature or unpublished. Some overseas research has also touched on local species. This review uses a historical approach to synthesize the southern African literature and to illustrate the cross-disciplinary, opportunistic nature of forensic entomology. Distinct phases of research focused on agriculture (1921-1950), medicine (1952- 1965), ecology (1968-1990) and forensics (1980-2005), but systematics spanned the entire period and tended to be ad hoc. Few scientists were involved, situated at geographically distant locations and with widely disparate research interests. The review concludes with an overview of southern African entomologists who have been involved in medico-legal investigations, and a critical evaluation of the past and future of the discipline locally.
- Full Text:
- Date Issued: 2006
A longitudinal cohort study of rural adolescent vs adult South African mothers and their children from birth to 24 months
- Authors: Karl le Roux1
- Date: 2019
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/11260/4626 , vital:44144
- Full Text:
- Authors: Karl le Roux1
- Date: 2019
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/11260/4626 , vital:44144
- Full Text:
A memorable band
- Unknown
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Gallotone , The Castle Lager Big Band , Jazz
- Language: English
- Type: Article
- Identifier: vital:13757 , http://hdl.handle.net/10962/d1012772
- Description: Photocopied article from the newspaper Pretoria News about the recordings by Chris McGregor and the Castle Lager Big Band.
- Full Text:
- Authors: Unknown
- Subjects: McGregor, Chris--1936-1990 , Gallotone , The Castle Lager Big Band , Jazz
- Language: English
- Type: Article
- Identifier: vital:13757 , http://hdl.handle.net/10962/d1012772
- Description: Photocopied article from the newspaper Pretoria News about the recordings by Chris McGregor and the Castle Lager Big Band.
- Full Text:
A newly discovered population of the critically endangered false limpet Siphonaria compressa Allanson, 1958 (Pulmonata: Siphonariidae), with observations on its reproductive biology
- Allanson, Brian R, Herbert, D G
- Authors: Allanson, Brian R , Herbert, D G
- Date: 2005-05-23
- Language: English
- Type: Article
- Identifier: vital:6833 , http://hdl.handle.net/10962/d1007570
- Description: The endangered false limpet, Siphonaria compressa, originally described by Allanson in 1958 from Langebaan Lagoon, Saldanha, has been found living in intertidal eelgrass meadows in the embayment of the Knysna River estuary at Bollard Bay, Leisure Isle, Knysna, South Africa. This represents only the second known site of occurrence of the species. Although classified by the IUCN as critically endangered, the Knysna population is viable. , Acrobat Distiller 6.0 (Windows)
- Full Text:
- Authors: Allanson, Brian R , Herbert, D G
- Date: 2005-05-23
- Language: English
- Type: Article
- Identifier: vital:6833 , http://hdl.handle.net/10962/d1007570
- Description: The endangered false limpet, Siphonaria compressa, originally described by Allanson in 1958 from Langebaan Lagoon, Saldanha, has been found living in intertidal eelgrass meadows in the embayment of the Knysna River estuary at Bollard Bay, Leisure Isle, Knysna, South Africa. This represents only the second known site of occurrence of the species. Although classified by the IUCN as critically endangered, the Knysna population is viable. , Acrobat Distiller 6.0 (Windows)
- Full Text:
A non-paraphyletic classification of the afrotropical genus Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae)
- Lugo-Ortiz, C R, Barber-James, Helen M, McCafferty, W P, De Moor, Ferdy C
- Authors: Lugo-Ortiz, C R , Barber-James, Helen M , McCafferty, W P , De Moor, Ferdy C
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:7006 , http://hdl.handle.net/10962/d1008384
- Description: Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae) is shown to be a monophyletic grouping defined by an anteromedially emarginate and laterally expanded and flattened pronotum in the larva. Attempts to restrict the concept of Acanthiops to Ac. marlieri (Demoulin) and re-erect Afroptiloides Gillies, syn. n., for Ac. elgonensis Lugo-Ortiz & McCafferty, Ac. griffithsi Lugo-Ortiz & McCafferty, Ac. tsitsa Barber-James & McCafferty, Ac. variegatus (Gillies), Ac. varius (Crass) and Ac. zomba Lugo-Ortiz & McCafferty, are shown to be based on inconsistent and inadequate morphological features that result in a paraphyletic taxonomy. The unofficial separate treatment of Ac. cooperi (Gillies & Wuillot) and Ac. erepens (Gillies) under Platycloeon Gillies & Wuillot is also shown to be paraphyletic. Acanthiops faro Barber-James & McCafferty, sp. n., is described from larvae from Guinea, and is distinguished by the combination of a papillate projection on labial palp segment 2, small tubercles on terga 1-8 and abdominal colour pattern. Acanthiops io Lugo-Ortiz & McCafferty, sp. n., is described from larvae from the Democratic Republic of Congo, and is distinguished by the combination of a papillate projection on palp segment 2, elongate tubercles on terga 1-9 and abdominal colour pattern. The larva of Ac. erepens (Gillies) is redescribed to incorporate morphological features and variability previously not accounted for, and larvae originally assigned to Baetis cataractae Crass are shown to be equivalent to Ac. erepens. New locality data or emendations on locality data are provided for Ac. griffithsi, Ac. tsitsa Barber-James & McCafferty and Ac. varius (Crass).
- Full Text:
- Date Issued: 2001
- Authors: Lugo-Ortiz, C R , Barber-James, Helen M , McCafferty, W P , De Moor, Ferdy C
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:7006 , http://hdl.handle.net/10962/d1008384
- Description: Acanthiops Waltz & McCafferty (Ephemeroptera: Baetidae) is shown to be a monophyletic grouping defined by an anteromedially emarginate and laterally expanded and flattened pronotum in the larva. Attempts to restrict the concept of Acanthiops to Ac. marlieri (Demoulin) and re-erect Afroptiloides Gillies, syn. n., for Ac. elgonensis Lugo-Ortiz & McCafferty, Ac. griffithsi Lugo-Ortiz & McCafferty, Ac. tsitsa Barber-James & McCafferty, Ac. variegatus (Gillies), Ac. varius (Crass) and Ac. zomba Lugo-Ortiz & McCafferty, are shown to be based on inconsistent and inadequate morphological features that result in a paraphyletic taxonomy. The unofficial separate treatment of Ac. cooperi (Gillies & Wuillot) and Ac. erepens (Gillies) under Platycloeon Gillies & Wuillot is also shown to be paraphyletic. Acanthiops faro Barber-James & McCafferty, sp. n., is described from larvae from Guinea, and is distinguished by the combination of a papillate projection on labial palp segment 2, small tubercles on terga 1-8 and abdominal colour pattern. Acanthiops io Lugo-Ortiz & McCafferty, sp. n., is described from larvae from the Democratic Republic of Congo, and is distinguished by the combination of a papillate projection on palp segment 2, elongate tubercles on terga 1-9 and abdominal colour pattern. The larva of Ac. erepens (Gillies) is redescribed to incorporate morphological features and variability previously not accounted for, and larvae originally assigned to Baetis cataractae Crass are shown to be equivalent to Ac. erepens. New locality data or emendations on locality data are provided for Ac. griffithsi, Ac. tsitsa Barber-James & McCafferty and Ac. varius (Crass).
- Full Text:
- Date Issued: 2001
A novel biosensor for the detection and monitoring of -d-galactosidase of faecal origin in water
- Wutor, V C, Togo, C A, Limson, Janice L, Pletschke, Brett I
- Authors: Wutor, V C , Togo, C A , Limson, Janice L , Pletschke, Brett I
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6468 , http://hdl.handle.net/10962/d1005797 , http://dx.doi.org/10.1016/j.enzmictec.2006.10.039
- Description: A voltammetric sensor prepared by the immobilization of metallophthalocyanine complexes onto a glassy carbon electrode has been developed for the detection of β-d-galactosidase (B-GAL) of faecal origin in water. Electrooxidation of chlorophenol red, a breakdown product of the chromogenic substrate chlorophenol red β-d-galactopyranoside, was used as a measure of β-d-galactosidase activity. At metallophthalocyanine modified electrodes, in particular copper(II) phthalocyanine, a decrease in electrode fouling was observed. The sensor was sensitive to fluctuations in pH, not significantly affected by temperature variations and could detect one colony forming unit/100 mL in 15 min. Loss of 40% sensitivity was observed over a period of 30 days. A strong correlation between sensor sensitivity and colony forming units was observed. The sensor is capable of detecting viable but nonculturable bacteria, overcoming this drawback of the use of culture media for detection of coliforms.
- Full Text:
- Date Issued: 2007
- Authors: Wutor, V C , Togo, C A , Limson, Janice L , Pletschke, Brett I
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6468 , http://hdl.handle.net/10962/d1005797 , http://dx.doi.org/10.1016/j.enzmictec.2006.10.039
- Description: A voltammetric sensor prepared by the immobilization of metallophthalocyanine complexes onto a glassy carbon electrode has been developed for the detection of β-d-galactosidase (B-GAL) of faecal origin in water. Electrooxidation of chlorophenol red, a breakdown product of the chromogenic substrate chlorophenol red β-d-galactopyranoside, was used as a measure of β-d-galactosidase activity. At metallophthalocyanine modified electrodes, in particular copper(II) phthalocyanine, a decrease in electrode fouling was observed. The sensor was sensitive to fluctuations in pH, not significantly affected by temperature variations and could detect one colony forming unit/100 mL in 15 min. Loss of 40% sensitivity was observed over a period of 30 days. A strong correlation between sensor sensitivity and colony forming units was observed. The sensor is capable of detecting viable but nonculturable bacteria, overcoming this drawback of the use of culture media for detection of coliforms.
- Full Text:
- Date Issued: 2007
A performative-performance analytical approach: infusing Butlerian theory into the narrative-discursive method
- Morison, Tracy, Macleod, Catriona I
- Authors: Morison, Tracy , Macleod, Catriona I
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6212 , http://hdl.handle.net/10962/d1003065 , http://dx.doi.org/10.1177/1077800413494344
- Description: Judith Butler’s theory of performativity provides gender theorists with a rich theoretical language for thinking about gender. Despite this, Butlerian theory is difficult to apply, as Butler does not provide guidance on actual analysis of language use in context. In order to address this limitation, we suggest carefully supplementing performativity with the notion of performance in a manner that allows for the inclusion of relational specificities and the mechanisms through which gender, and gender trouble, occur. To do this, we turn to current developments within discursive psychology and narrative theory. We extend the narrative-discursive method proposed by Taylor and colleagues, infusing it with Butlerian theory in order to fashion a dual analytical lens, which we call the performativity-performance approach. We provide a brief example of how the proposed analytical process may be implemented.
- Full Text:
- Date Issued: 2013
- Authors: Morison, Tracy , Macleod, Catriona I
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6212 , http://hdl.handle.net/10962/d1003065 , http://dx.doi.org/10.1177/1077800413494344
- Description: Judith Butler’s theory of performativity provides gender theorists with a rich theoretical language for thinking about gender. Despite this, Butlerian theory is difficult to apply, as Butler does not provide guidance on actual analysis of language use in context. In order to address this limitation, we suggest carefully supplementing performativity with the notion of performance in a manner that allows for the inclusion of relational specificities and the mechanisms through which gender, and gender trouble, occur. To do this, we turn to current developments within discursive psychology and narrative theory. We extend the narrative-discursive method proposed by Taylor and colleagues, infusing it with Butlerian theory in order to fashion a dual analytical lens, which we call the performativity-performance approach. We provide a brief example of how the proposed analytical process may be implemented.
- Full Text:
- Date Issued: 2013
A phenomenological case study of a lecturer's understanding of himself as an assessor
- Authors: Grant, Rose
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6087 , http://hdl.handle.net/10962/d1008582
- Description: Based on the findings of research conducted as part of a doctoral study aimed at obtaining an understanding of what it means to be an assessor in higher education, this paper outlines the experience of an individual lecturer at a South African university and describes the meaning he makes of his practice as an assessor within the context of a changing understanding of the nature and purpose of higher education. Making a case for personal agency and innovation as critical qualities in the assessment endeavour, the researcher suggests that, in contrast to a view of education increasingly focused on standardization, accountability and outcomes, student assessment is essentially a human encounter in which the humanity and emotions of both lecturer and student need to be acknowledged.
- Full Text:
- Date Issued: 2008
- Authors: Grant, Rose
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6087 , http://hdl.handle.net/10962/d1008582
- Description: Based on the findings of research conducted as part of a doctoral study aimed at obtaining an understanding of what it means to be an assessor in higher education, this paper outlines the experience of an individual lecturer at a South African university and describes the meaning he makes of his practice as an assessor within the context of a changing understanding of the nature and purpose of higher education. Making a case for personal agency and innovation as critical qualities in the assessment endeavour, the researcher suggests that, in contrast to a view of education increasingly focused on standardization, accountability and outcomes, student assessment is essentially a human encounter in which the humanity and emotions of both lecturer and student need to be acknowledged.
- Full Text:
- Date Issued: 2008
A possible relation between dietary zinc and cAMP in the regulation of tumour cell proliferation in the rat
- Skeef, Noel S, Duncan, John R
- Authors: Skeef, Noel S , Duncan, John R
- Date: 1988
- Language: English
- Type: Article
- Identifier: vital:6473 , http://hdl.handle.net/10962/d1006154 , http://dx.doi.org/10.1079/BJN19880052
- Description: The possibility of an effect of zinc on the rate of tumour cell division, mediated through a regulation of cellular cAMP concentration, was investigated in the present study in rats. Dietary Zn deficiency (< 1·5 mg Zn/kg) but not Zn excess (500 mg Zn/kg) resulted in an increased cAMP concentration in transplanted hepatoma cells. Neither treatment had any effect on the cAMP concentration in regenerating liver or normal resting liver. Both the deficient and excess Zn diets resulted in a small reduction in tumour growth (not statistically significant). The results seem to indicate that the relation investigated in the present study does not apply in the cell line used.
- Full Text:
- Date Issued: 1988
- Authors: Skeef, Noel S , Duncan, John R
- Date: 1988
- Language: English
- Type: Article
- Identifier: vital:6473 , http://hdl.handle.net/10962/d1006154 , http://dx.doi.org/10.1079/BJN19880052
- Description: The possibility of an effect of zinc on the rate of tumour cell division, mediated through a regulation of cellular cAMP concentration, was investigated in the present study in rats. Dietary Zn deficiency (< 1·5 mg Zn/kg) but not Zn excess (500 mg Zn/kg) resulted in an increased cAMP concentration in transplanted hepatoma cells. Neither treatment had any effect on the cAMP concentration in regenerating liver or normal resting liver. Both the deficient and excess Zn diets resulted in a small reduction in tumour growth (not statistically significant). The results seem to indicate that the relation investigated in the present study does not apply in the cell line used.
- Full Text:
- Date Issued: 1988
A preliminary investigation of spinal kinematics during sugar cane harvesting
- Authors: Todd, Andrew I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6759 , http://hdl.handle.net/10962/d1009462
- Description: The sugar cane industry forms a significant portion of the South African economy, and unlike many other countries the harvesting of sugar cane in South Africa remains manual in nature. The focus of the present study was therefore on the assessment of spinal kinematics (range of motion, velocities and accelerations in all three cardinal planes) during the harvesting process. Eight workers were recruited from the Illovo Esperanza farm in Kwa-zulu Natal as subjects for the study. The experimental protocol was conducted in situ and required subjects to cut the sugar cane using specially modified knives as they would under normal harvesting conditions. The motion performance was quantified using the lumbar motion monitor (LMM), a triaxial electrogoniometer. Results indicate that the harvesting of sugar cane places excessive demands on the spine. During cutting, subjects were required to maintain the spine in a high degree of flexion throughout the task which also demonstrated significant twisting and lateral bending. Of particular concern were the high lateral velocities (ranging between 50 and 90 m.s-1), as this is a key risk factor in the development of lower back pain. It is evident from these results that new techniques of harvesting sugar cane are essential to reduce the rate of injury within this industry.
- Full Text:
- Date Issued: 2008
- Authors: Todd, Andrew I
- Date: 2008
- Language: English
- Type: Article
- Identifier: vital:6759 , http://hdl.handle.net/10962/d1009462
- Description: The sugar cane industry forms a significant portion of the South African economy, and unlike many other countries the harvesting of sugar cane in South Africa remains manual in nature. The focus of the present study was therefore on the assessment of spinal kinematics (range of motion, velocities and accelerations in all three cardinal planes) during the harvesting process. Eight workers were recruited from the Illovo Esperanza farm in Kwa-zulu Natal as subjects for the study. The experimental protocol was conducted in situ and required subjects to cut the sugar cane using specially modified knives as they would under normal harvesting conditions. The motion performance was quantified using the lumbar motion monitor (LMM), a triaxial electrogoniometer. Results indicate that the harvesting of sugar cane places excessive demands on the spine. During cutting, subjects were required to maintain the spine in a high degree of flexion throughout the task which also demonstrated significant twisting and lateral bending. Of particular concern were the high lateral velocities (ranging between 50 and 90 m.s-1), as this is a key risk factor in the development of lower back pain. It is evident from these results that new techniques of harvesting sugar cane are essential to reduce the rate of injury within this industry.
- Full Text:
- Date Issued: 2008
A preliminary report on the age and significance of Quaternary lacustrine deposits at Birnam, north-east Cape Province, South Africa
- Hanvey, Patricia M, Lewis, Colin A
- Authors: Hanvey, Patricia M , Lewis, Colin A
- Date: 1990
- Language: English
- Type: Article
- Identifier: vital:6686 , http://hdl.handle.net/10962/d1006688
- Description: The paper presents the results of preliminary investigations at Birnam, in the Rhodes area of the eastern Cape Drakensberg, which may have important implications for palaeoenvironmental reconstructions in Southern Africa. A study has been undertaken on a sedimentary sequence exposed by fluvial incision on the outer bend of the River Bokspruit, at an altitude of 1850 m.
- Full Text: false
- Date Issued: 1990
- Authors: Hanvey, Patricia M , Lewis, Colin A
- Date: 1990
- Language: English
- Type: Article
- Identifier: vital:6686 , http://hdl.handle.net/10962/d1006688
- Description: The paper presents the results of preliminary investigations at Birnam, in the Rhodes area of the eastern Cape Drakensberg, which may have important implications for palaeoenvironmental reconstructions in Southern Africa. A study has been undertaken on a sedimentary sequence exposed by fluvial incision on the outer bend of the River Bokspruit, at an altitude of 1850 m.
- Full Text: false
- Date Issued: 1990
A preliminary survey of the estuaries on the south coast of South Africa, Cape St Blaize, Mossel Bay - Robberg Peninsula, Plettenberg Bay, with particular reference to the fish fauna
- James, Nicola Caroline, Harrison, T D
- Authors: James, Nicola Caroline , Harrison, T D
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7141 , http://hdl.handle.net/10962/d1011834
- Description: The coastal river systems on the south coast of South Africa from Cape St Blaize to Robberg Peninsula were surveyed during October and November 1994. The ichthyofaunal and physico-chemical characteristics of each system are presented and their suitability as estuarine nursery areas is discussed. Five systems (Rooi, Meul, Grooteiland, Kranshoek and Crooks) are outlets of small coastal streams and probably provide little or no habitat for either resident estuarine or migrant marine fishes owing to their small size. Four systems (Maalgate, Gwaing, Skaapkop and Kaaimans) are located within deeply incised valleys and have a permanent connection with the sea. The amount of marginal and intertidal habitat available to fishes, however, is limited due to their morphology. Six systems (Hartenbos, Groot Brak, Touw, Swartvlei, Goukamma and Noetsie) are intermittently open to the sea. Although the Touw and Swartvlei are connected to coastal lake systems, flow within these estuaries is not sufficient to prevent the build up of a sand barrier at the mouth. The Hartenbos, Groot Brak, Goukamma, and Noetsie are also periodically closed by a sand bar. The construction of a dam in the lower catchment of the Groot Brak has affected the hydrology of the system. The two remaining estuaries (Klein Brak and Knysna) are permanently open. In addition to strong tidal currents, the fixing of the mouth of the Knysna Estuary between rocky headlands also serves to maintain a permanent connection with the sea. Mugilidae and Sparidae were represented by the greatest number of species, and also dominated catches numerically and by mass. The fish fauna of all the estuaries surveyed were dominated by the juveniles of estuarine-dependent marine species and estuarine-resident species were also well represented in catches. The estuaries surveyed provide a vital habitat for both marine migrant species and resident species, most of which are endemic to the region.
- Full Text:
- Date Issued: 2008
- Authors: James, Nicola Caroline , Harrison, T D
- Date: 2008
- Language: English
- Type: text , Article
- Identifier: vital:7141 , http://hdl.handle.net/10962/d1011834
- Description: The coastal river systems on the south coast of South Africa from Cape St Blaize to Robberg Peninsula were surveyed during October and November 1994. The ichthyofaunal and physico-chemical characteristics of each system are presented and their suitability as estuarine nursery areas is discussed. Five systems (Rooi, Meul, Grooteiland, Kranshoek and Crooks) are outlets of small coastal streams and probably provide little or no habitat for either resident estuarine or migrant marine fishes owing to their small size. Four systems (Maalgate, Gwaing, Skaapkop and Kaaimans) are located within deeply incised valleys and have a permanent connection with the sea. The amount of marginal and intertidal habitat available to fishes, however, is limited due to their morphology. Six systems (Hartenbos, Groot Brak, Touw, Swartvlei, Goukamma and Noetsie) are intermittently open to the sea. Although the Touw and Swartvlei are connected to coastal lake systems, flow within these estuaries is not sufficient to prevent the build up of a sand barrier at the mouth. The Hartenbos, Groot Brak, Goukamma, and Noetsie are also periodically closed by a sand bar. The construction of a dam in the lower catchment of the Groot Brak has affected the hydrology of the system. The two remaining estuaries (Klein Brak and Knysna) are permanently open. In addition to strong tidal currents, the fixing of the mouth of the Knysna Estuary between rocky headlands also serves to maintain a permanent connection with the sea. Mugilidae and Sparidae were represented by the greatest number of species, and also dominated catches numerically and by mass. The fish fauna of all the estuaries surveyed were dominated by the juveniles of estuarine-dependent marine species and estuarine-resident species were also well represented in catches. The estuaries surveyed provide a vital habitat for both marine migrant species and resident species, most of which are endemic to the region.
- Full Text:
- Date Issued: 2008