Recent African derivation of Chrysomya putoria from C. chloropyga and mitochondrial DNA paraphyly of cytochrome oxidase subunit one in blowflies of forensic importance
- Wells, J D, Lunt, N, Villet, Martin H
- Authors: Wells, J D , Lunt, N , Villet, Martin H
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6888 , http://hdl.handle.net/10962/d1011648
- Description: Chrysomya chloropyga (Wiedemann) and C. putoria (Wiedemann) (Diptera: Calliphoridae) are closely related Afrotropical blowflies that breed in carrion and latrines, reaching high density in association with humans and spreading to other continents. In some cases of human death, Chyrsomya specimens provide forensic clues. Because the immature stages of such flies are often difficult to identify taxonomically, it is useful to develop DNA-based tests for specimen identification. Therefore we attempted to distinguish between C. chloropyga and C. putoria using mitochondrial DNA (mtDNA) sequence data from a 593-bp region of the gene for cytochrome oxidase subunit one (COI). Twelve specimens from each species yielded a total of five haplotypes, none being unique to C. putoria. Therefore it was not possible to distinguish between the two species using this locus. Maximum parsimony analysis indicated paraphyletic C. chloropyga mtDNA with C. putoria nested therein. Based on these and previously published data, we infer that C. putoria diverged very recently from C. chloropyga.
- Full Text:
- Date Issued: 2004
- Authors: Wells, J D , Lunt, N , Villet, Martin H
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6888 , http://hdl.handle.net/10962/d1011648
- Description: Chrysomya chloropyga (Wiedemann) and C. putoria (Wiedemann) (Diptera: Calliphoridae) are closely related Afrotropical blowflies that breed in carrion and latrines, reaching high density in association with humans and spreading to other continents. In some cases of human death, Chyrsomya specimens provide forensic clues. Because the immature stages of such flies are often difficult to identify taxonomically, it is useful to develop DNA-based tests for specimen identification. Therefore we attempted to distinguish between C. chloropyga and C. putoria using mitochondrial DNA (mtDNA) sequence data from a 593-bp region of the gene for cytochrome oxidase subunit one (COI). Twelve specimens from each species yielded a total of five haplotypes, none being unique to C. putoria. Therefore it was not possible to distinguish between the two species using this locus. Maximum parsimony analysis indicated paraphyletic C. chloropyga mtDNA with C. putoria nested therein. Based on these and previously published data, we infer that C. putoria diverged very recently from C. chloropyga.
- Full Text:
- Date Issued: 2004
Science after a century at Rhodes University
- Authors: Woods, D R
- Date: 2004
- Language: English
- Type: Article , text
- Identifier: vital:7123 , http://hdl.handle.net/10962/d1006584
- Description: Rhodes Centenary issue , The small University of Rhodes (6142 students), in the rural city of Grahamstown, was established in 1904 as a result of a £50 000 grant from the Rhodes Trust in Oxford. It grew out of St Andrew’s College, which provided the first four professors and 41 students. The first paper from Rhodes in the South African Journal of Science (then called the Report of the South African Association for the Advancement of Science) was by Selmar Schonland, one of the university’s founding fathers. Entitled: ‘Biological and ethnological observations on a trip to the N.E. Kalahari’, it appeared in 1904. The following pages provide a glimpse into the growth and achievements of various departments in the faculties of Science and Pharmacy and associated institutes a century after the university was born.
- Full Text:
- Date Issued: 2004
- Authors: Woods, D R
- Date: 2004
- Language: English
- Type: Article , text
- Identifier: vital:7123 , http://hdl.handle.net/10962/d1006584
- Description: Rhodes Centenary issue , The small University of Rhodes (6142 students), in the rural city of Grahamstown, was established in 1904 as a result of a £50 000 grant from the Rhodes Trust in Oxford. It grew out of St Andrew’s College, which provided the first four professors and 41 students. The first paper from Rhodes in the South African Journal of Science (then called the Report of the South African Association for the Advancement of Science) was by Selmar Schonland, one of the university’s founding fathers. Entitled: ‘Biological and ethnological observations on a trip to the N.E. Kalahari’, it appeared in 1904. The following pages provide a glimpse into the growth and achievements of various departments in the faculties of Science and Pharmacy and associated institutes a century after the university was born.
- Full Text:
- Date Issued: 2004
The development of a toxicity database using freshwater macroinvertebrates, and its application to the protection of South African water resources
- Palmer, Carolyn G, Muller, Wilhelmine J, Gordon, Andrew K, Scherman, Patricia A, Davies-Coleman, Heather D, Pakhomova, L, de Kock, E
- Authors: Palmer, Carolyn G , Muller, Wilhelmine J , Gordon, Andrew K , Scherman, Patricia A , Davies-Coleman, Heather D , Pakhomova, L , de Kock, E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7073 , http://hdl.handle.net/10962/d1009528
- Description: There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.
- Full Text:
- Date Issued: 2004
- Authors: Palmer, Carolyn G , Muller, Wilhelmine J , Gordon, Andrew K , Scherman, Patricia A , Davies-Coleman, Heather D , Pakhomova, L , de Kock, E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7073 , http://hdl.handle.net/10962/d1009528
- Description: There is a growing international trend towards the protection of freshwater resources from pollution by imposing instream guidelines and specified waste-discharge conditions. Current methods for devising freshwater quality guidelines are based on species sensitivity distributions (SSDs) that are used to identify pollutant concentrations, ensuring the protection of a modelled percentage of species (95% protection is a common goal). SSDs are derived from the toxicity test results of as many taxa as possible for each polluting substance. Waste-discharge licences can be for single substances, specified in terms of chemical concentrations, and derived in conjunction with instream guidelines; or for complex mixtures, specified in terms of toxic units. In both cases toxicity test results are the core data used. The emphasis on SSDs calls into question the species constituting the test populations. It is likely that SSDs based in part on the responses of local organisms will achieve superior site-specific ecological protection. Until the early 1990s, there were very few data on the tolerances of South African freshwater organisms. In the intervening decade, the Unilever Centre for Environmental Water Quality at Rhodes University has developed a toxicity database that, to date, records the responses of 21 South African freshwater taxa to 26 single-substance pollutants or mixtures. This is the most comprehensive database of South African toxicity responses available and has been used in the drawing up of methods and guidelines to protect water resources. This paper aims to make these data available and to describe applications of the data using selected case studies.
- Full Text:
- Date Issued: 2004
The wing coupling apparatus and the morphometric analysis of honeybee populations
- Hepburn, H Randall, Radloff, Sarah E
- Authors: Hepburn, H Randall , Radloff, Sarah E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6904 , http://hdl.handle.net/10962/d1011760
- Description: Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.
- Full Text:
- Date Issued: 2004
- Authors: Hepburn, H Randall , Radloff, Sarah E
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:6904 , http://hdl.handle.net/10962/d1011760
- Description: Significant differences between countries were found in the distribution of the number of hamuli within Apis andreniformis, A. florea, A. cerana and A. koschevnikovi. The mean hamuli numbers for Apis mellifera intermissa differed significantly among localities in Algeria. Significant differences in intercolonial variability between countries were found within A. cerana. There was no significant infraspecific variability within A. andreniformis, A. florea, A. koschevnikovi and A. m. intermissa. Significant differences in the mean number of hamuli occur between A. m. intermissa and A. andreniformis, A. florea and A. cerana; also between A. cerana/A. koschevnikovi and A. andreniformis and A. florea. Significant differences were found in the distribution and variability of the number of hamuli between species (populations). The mean numbers of hamuli for A. andreniformis differed from those of A. florea. Both these population means differed from those of A. cerana, A. koschevnikovi and A. m. intermissa. No significant differences were found between A. cerana and A. koschevnikovi. When the analysis included data for A. dorsata, A. nigrocincta, A. m. carnica, A. m. caucasica and A. m. ligustica, the results showed significant differences in hamuli numbers between A. andreniformis/A. florea and A. cerana/A. koschevnikovi/A. nigrocincta and A. m. intermissa/A. m. carnica/A. m. caucasica/A. m. ligustica. Hamuli numbers in A. dorsata significantly differed from those of other populations except A. m. intermissa. These results show that hamuli numbers are useful in the classification of honeybee populations. Whether hamuli would be useful in multivariate analysis depends on the correlation between the number of hamuli and the other characters used.
- Full Text:
- Date Issued: 2004
Three decades of hydrological modelling research in South Africa
- Authors: Hughes, Denis A
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7072 , http://hdl.handle.net/10962/d1009526
- Description: This paper presents a review of the research undertaken in the field of hydrological modelling over roughly the last three decades, concentrating primarily on South African work in an international context. The focus is on deterministic, rainfall-runoff models and addresses issues related to model design as well as to the application of models in practice. I provide a brief description of what hydrological models are and what they are used for and discuss also the following issues: • Developments in understanding hydrological process and the extent to which these have filtered down into models. • Model calibration and parameter estimation. • Trends in data availability and how these have affected model development. • Trends in computer technology and their impacts on model development. I suggest that there have been substantial developments in the science and practice of hydrological modelling, but that there remain many problems that need to be addressed to improve the ability of models to contribute to the solution of problems of water resource management. Southern African scientists have contributed to the body of knowledge on hydrological modelling, despite the limited resources available compared to resources elsewhere. Internationally, the focus has not always been on the practical issues of model application and has commonly tended towards the more theoretical and mathematical issues of model calibration. This is not a trend that has found much favour in southern Africa (particularly amongst research funding agencies), where there are many problems of water resource management that have the potential to be resolved with existing models, applied in an appropriate way. The paper concludes by suggesting that further research needs to focus on the integration of the best in international developments with the tried and tested models that have been developed locally. The context of this research should be the search for more reliable estimations of water resource availability.
- Full Text:
- Date Issued: 2004
- Authors: Hughes, Denis A
- Date: 2004
- Language: English
- Type: text , Article
- Identifier: vital:7072 , http://hdl.handle.net/10962/d1009526
- Description: This paper presents a review of the research undertaken in the field of hydrological modelling over roughly the last three decades, concentrating primarily on South African work in an international context. The focus is on deterministic, rainfall-runoff models and addresses issues related to model design as well as to the application of models in practice. I provide a brief description of what hydrological models are and what they are used for and discuss also the following issues: • Developments in understanding hydrological process and the extent to which these have filtered down into models. • Model calibration and parameter estimation. • Trends in data availability and how these have affected model development. • Trends in computer technology and their impacts on model development. I suggest that there have been substantial developments in the science and practice of hydrological modelling, but that there remain many problems that need to be addressed to improve the ability of models to contribute to the solution of problems of water resource management. Southern African scientists have contributed to the body of knowledge on hydrological modelling, despite the limited resources available compared to resources elsewhere. Internationally, the focus has not always been on the practical issues of model application and has commonly tended towards the more theoretical and mathematical issues of model calibration. This is not a trend that has found much favour in southern Africa (particularly amongst research funding agencies), where there are many problems of water resource management that have the potential to be resolved with existing models, applied in an appropriate way. The paper concludes by suggesting that further research needs to focus on the integration of the best in international developments with the tried and tested models that have been developed locally. The context of this research should be the search for more reliable estimations of water resource availability.
- Full Text:
- Date Issued: 2004
The Educational Journal
- Date: 2003-12
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38670 , vital:34867 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-12
- Date: 2003-12
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38670 , vital:34867 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-12
The Educational Journal
- Date: 2003-10
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38724 , vital:34884 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-10
- Date: 2003-10
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38724 , vital:34884 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-10
The Educational Journal
- Date: 2003-08
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38429 , vital:34763 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-08
- Date: 2003-08
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38429 , vital:34763 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-08
New Unity Movement Bulletin
- Date: 2003-07
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/33748 , vital:33013 , Bulk File 7
- Description: The Bulletin was the official newsletter of the New Unity Movement. It was published about twice a year and contained articles reflecting the organisation's views on resistance to the Apartheid government.
- Full Text: false
- Date Issued: 2003-07
- Date: 2003-07
- Subjects: Government, Resistance to -- South Africa , South Africa -- History -- 20th century , South Africa -- Politics and government
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/33748 , vital:33013 , Bulk File 7
- Description: The Bulletin was the official newsletter of the New Unity Movement. It was published about twice a year and contained articles reflecting the organisation's views on resistance to the Apartheid government.
- Full Text: false
- Date Issued: 2003-07
The Educational Journal
- Date: 2003-06
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38609 , vital:34839 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-06
- Date: 2003-06
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38609 , vital:34839 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-06
The Educational Journal
- Date: 2003-05
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38339 , vital:34589 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-05
- Date: 2003-05
- Subjects: Education – South Africa , South Africa – Economic conditions , South Africa – Social conditions
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/10948/38339 , vital:34589 , Bulk File 7
- Description: The Educational Journal was the official organ of the Teachers' League of South Africa and focussed on education within the context of a racialized South Africa. From the 2000s, the journal was published by the National Union of Public Service and Allied Workers (NUPSAW), a trade union formed in August 1998 from the amalgamation of militant and moderate trade unions and also operated in the education sphere.
- Full Text: false
- Date Issued: 2003-05
6-Hydroxymelatonin protects against cyanide induced oxidative stress in rat brain homogenates
- Maharaj, Deepa S, Walker, Roderick B, Glass, Beverley D, Daya, Santylal
- Authors: Maharaj, Deepa S , Walker, Roderick B , Glass, Beverley D , Daya, Santylal
- Date: 2003
- Language: English
- Type: Article , text
- Identifier: vital:6405 , http://hdl.handle.net/10962/d1006478
- Description: Both 6-hydroxymelatonin and N-acetyl-N-formyl-5-methoxykynurenamine are photodegradants and enzymatic metabolites of melatonin and are known to retain equipotent activity against potassium cyanide-induced superoxide generation compared to melatonin. It is not clear whether one or both of these metabolites is responsible for this effect. The present study therefore investigates the possible manner in which 6-hydroxymelatonin protects against oxidative stress induced by cyanide in rat brain homogenates. We examined the ability of 6-hydroxymelatonin to scavenge KCN-induced superoxide anion generation as well as lipid peroxidation. In addition, we also examined the effect of this indole on lactate dehydrogenase activity (LDH) as well as mitochondrial electron transport using dichlorophenol–indophenol as an electron acceptor. The results of this study show that 6-hydroxymelatonin significantly reduces KCN-induced superoxide anion generation, which is accompanied by a commensurate reduction in lipid peroxidation. Partial reversal of the KCN-induced reduction in mitochondrial electron transport is accompanied by a similar reversal of mitochondrial LDH activity blunted by KCN. It can thus be proposed that 6-hydroxymelatonin is potentially neuroprotective against KCN-induced neurotoxicity.
- Full Text:
- Date Issued: 2003
- Authors: Maharaj, Deepa S , Walker, Roderick B , Glass, Beverley D , Daya, Santylal
- Date: 2003
- Language: English
- Type: Article , text
- Identifier: vital:6405 , http://hdl.handle.net/10962/d1006478
- Description: Both 6-hydroxymelatonin and N-acetyl-N-formyl-5-methoxykynurenamine are photodegradants and enzymatic metabolites of melatonin and are known to retain equipotent activity against potassium cyanide-induced superoxide generation compared to melatonin. It is not clear whether one or both of these metabolites is responsible for this effect. The present study therefore investigates the possible manner in which 6-hydroxymelatonin protects against oxidative stress induced by cyanide in rat brain homogenates. We examined the ability of 6-hydroxymelatonin to scavenge KCN-induced superoxide anion generation as well as lipid peroxidation. In addition, we also examined the effect of this indole on lactate dehydrogenase activity (LDH) as well as mitochondrial electron transport using dichlorophenol–indophenol as an electron acceptor. The results of this study show that 6-hydroxymelatonin significantly reduces KCN-induced superoxide anion generation, which is accompanied by a commensurate reduction in lipid peroxidation. Partial reversal of the KCN-induced reduction in mitochondrial electron transport is accompanied by a similar reversal of mitochondrial LDH activity blunted by KCN. It can thus be proposed that 6-hydroxymelatonin is potentially neuroprotective against KCN-induced neurotoxicity.
- Full Text:
- Date Issued: 2003
Analysis of the calling songs of Platypleura hirtipennis (Germar, 1834) and P. plumosa (Germar, 1834) (Hemiptera: Cicadidae)
- Sanborn, Allen F, Phillips, P K, Villet, Martin H
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6896 , http://hdl.handle.net/10962/d1011656
- Description: [From the introduction]: Most male cicadas produce a calling song in order to attract conspecific females. These songs have been shown to differ in closely related species (e.g. Alexander & Moore 1962; Villet 1988, 1989; Boulard 1995; Marshall & Cooley 2000; Sanborn & Phillips 2001) and in species which share habitats (e.g. Sueur 2002). The former is an inevitable part of the divergence of recognition signals that characterizes the speciation process in animals using acoustic signals (Villet 1995), while the latter would be expected from a signal that acts as a reproductive isolating mechanism (Claridge 1985; Marshall & Cooley 2000). Calling songs are therefore of value in resolving taxonomic problems in the cicadas.
- Full Text:
- Date Issued: 2003
Endothermy and chorusing behaviour in the African platypleurine cicada Pycna semiclara (Germar, 1834) (Hemiptera: Cicadidae)
- Villet, Martin H, Sanborn, Allen F, Phillips, P K
- Authors: Villet, Martin H , Sanborn, Allen F , Phillips, P K
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6892 , http://hdl.handle.net/10962/d1011652 , http://dx.doi.org/10.1139/z03-119
- Description: Cicadas use acoustic signals to find mates and therefore offer a phylogenetically independent opportunity to test the generality of ideas about acoustic communication that were developed from studies of other animals. Pycna semiclara (Germar, 1834) (Hemiptera: Cicadidae) is a forest-dwelling platypleurine cicada that uses its calling song to form choruses and attract mates. Additionally, P. semiclara produces an encounter call that is involved in courtship and also in spacing males within choruses. Males generally call from exposed trunks and branches within the understory but clear of the undergrowth and fight with other males that call within about 50 cm of them. Choruses sing sporadically throughout the day but focus most of their calling activity into half-hour bouts at dawn and dusk. Body size and ambient temperature had no significant effect on spectral or temporal characteristics of the calling song. Body temperature measurements indicate that P. semiclara thermoregulates endothermically, with a body temperature of more than 22 °C above ambient temperature being measured during calling activity at dusk. Such endothermy provides an advantage to the cicadas by allowing them to call during crepuscular hours when atmospheric conditions are most optimal for acoustic communication and predation risks are minimal. Coincidentally, endogenously regulating body temperature allows the temporal characteristics of the call to be unaffected by ambient temperature changes.
- Full Text:
- Date Issued: 2003
- Authors: Villet, Martin H , Sanborn, Allen F , Phillips, P K
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6892 , http://hdl.handle.net/10962/d1011652 , http://dx.doi.org/10.1139/z03-119
- Description: Cicadas use acoustic signals to find mates and therefore offer a phylogenetically independent opportunity to test the generality of ideas about acoustic communication that were developed from studies of other animals. Pycna semiclara (Germar, 1834) (Hemiptera: Cicadidae) is a forest-dwelling platypleurine cicada that uses its calling song to form choruses and attract mates. Additionally, P. semiclara produces an encounter call that is involved in courtship and also in spacing males within choruses. Males generally call from exposed trunks and branches within the understory but clear of the undergrowth and fight with other males that call within about 50 cm of them. Choruses sing sporadically throughout the day but focus most of their calling activity into half-hour bouts at dawn and dusk. Body size and ambient temperature had no significant effect on spectral or temporal characteristics of the calling song. Body temperature measurements indicate that P. semiclara thermoregulates endothermically, with a body temperature of more than 22 °C above ambient temperature being measured during calling activity at dusk. Such endothermy provides an advantage to the cicadas by allowing them to call during crepuscular hours when atmospheric conditions are most optimal for acoustic communication and predation risks are minimal. Coincidentally, endogenously regulating body temperature allows the temporal characteristics of the call to be unaffected by ambient temperature changes.
- Full Text:
- Date Issued: 2003
Foam drug delivery in dermatology: beyond the scalp
- Purdon, Carryn H, Haigh, John M, Surber, Christian, Smith, Eric W
- Authors: Purdon, Carryn H , Haigh, John M , Surber, Christian , Smith, Eric W
- Date: 2003
- Subjects: Adis International Limited , Drug delivery systems , Skin disorders
- Language: English
- Type: text , Article
- Identifier: vital:6418 , http://hdl.handle.net/10962/d1006541
- Description: Consumers of topical formulations apply a wide spectrum of preparations, both cosmetic and dermatological, to their healthy or diseased skin. These formulations range in physicochemical nature from solid through semisolid to liquid. Pharmaceutical foams are pressurized dosage forms containing one or more active ingredients that, upon valve actuation, emit a fine dispersion of liquid and/or solid materials in a gaseous medium. Foam formulations are generally easier to apply, are less dense, and spread more easily than other topical dosage forms. Foams may be formulated in various ways to provide emollient or drying functions to the skin, depending on the formulation constituents. Therefore, this delivery technology should be a useful addition to the spectrum of formulations available for topical use; however, as yet, only a few are commercially available. Probably the most convincing argument for the use of foams is ease of use by the patient, and consumer acceptance. Most foam dosage forms used in dermatology to date have incorporated corticosteroids, although some products have also been used to deliver antiseptics, antifungal agents, anti-inflammatory agents, local anesthetic agents, skin emollients, and protectants. Although there is no clinical evidence that foam formulations are currently superior to other conventional delivery vehicles, these formulations have a clear application advantage and with continued developments in the science of supersaturation technology, it seems certain that foam delivery systems will retain their place in the dermatological and cosmetic armamentarium.
- Full Text:
- Date Issued: 2003
- Authors: Purdon, Carryn H , Haigh, John M , Surber, Christian , Smith, Eric W
- Date: 2003
- Subjects: Adis International Limited , Drug delivery systems , Skin disorders
- Language: English
- Type: text , Article
- Identifier: vital:6418 , http://hdl.handle.net/10962/d1006541
- Description: Consumers of topical formulations apply a wide spectrum of preparations, both cosmetic and dermatological, to their healthy or diseased skin. These formulations range in physicochemical nature from solid through semisolid to liquid. Pharmaceutical foams are pressurized dosage forms containing one or more active ingredients that, upon valve actuation, emit a fine dispersion of liquid and/or solid materials in a gaseous medium. Foam formulations are generally easier to apply, are less dense, and spread more easily than other topical dosage forms. Foams may be formulated in various ways to provide emollient or drying functions to the skin, depending on the formulation constituents. Therefore, this delivery technology should be a useful addition to the spectrum of formulations available for topical use; however, as yet, only a few are commercially available. Probably the most convincing argument for the use of foams is ease of use by the patient, and consumer acceptance. Most foam dosage forms used in dermatology to date have incorporated corticosteroids, although some products have also been used to deliver antiseptics, antifungal agents, anti-inflammatory agents, local anesthetic agents, skin emollients, and protectants. Although there is no clinical evidence that foam formulations are currently superior to other conventional delivery vehicles, these formulations have a clear application advantage and with continued developments in the science of supersaturation technology, it seems certain that foam delivery systems will retain their place in the dermatological and cosmetic armamentarium.
- Full Text:
- Date Issued: 2003
Hot-blooded singers: endothermy facilitates crepuscular signaling in African platypleurine cicadas (Hemiptera: Cicadidae: Platypleura spp.)
- Sanborn, Allen F, Villet, Martin H, Phillips, P K
- Authors: Sanborn, Allen F , Villet, Martin H , Phillips, P K
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6919 , http://hdl.handle.net/10962/d1011882
- Description: The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature (Tb) show that these animals regulate Tb through endogenous heat production. Maximum Tb measured was 22.1°C above ambient temperature during calling activity at dusk. The mean Tb during dusk activity did not differ from the mean Tb during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate Tb. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Villet, Martin H , Phillips, P K
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6919 , http://hdl.handle.net/10962/d1011882
- Description: The cicada genus Platypleura has a wide distribution across Africa and southern Asia. We describe endothermic thermoregulation in four South African species that show crepuscular signaling behavior. This is the first evidence of thermoregulation in platypleurine cicadas. Field measurements of body temperature (Tb) show that these animals regulate Tb through endogenous heat production. Maximum Tb measured was 22.1°C above ambient temperature during calling activity at dusk. The mean Tb during dusk activity did not differ from the mean Tb during diurnal activity. A unique behavior for cicadas, a temperature-dependent telescoping pulsation of the abdomen, was observed in the laboratory during endogenous warm-up. This behavior is part of a unique method of heat generation in endothermic cicadas. Males generally call from trunks and branches within the canopy and appear to use endothermy even when the sun is available to elevate Tb. Endothermy may provide the cicadas with the advantage of decreasing predation and acoustic competition by permitting calling from perches that most complement their cryptic coloration patterns and that ectotherms cannot use due to thermal constraints. In addition, endothermy may permit calling activity during crepuscular hours when atmospheric conditions are optimal for acoustic communication and predation risks are minimal.
- Full Text:
- Date Issued: 2003
Molecular identification of some forensically important blowflies of southern Africa and Australia
- Harvey, M L, Mansell, M W, Villet, Martin H, Dadour, I R
- Authors: Harvey, M L , Mansell, M W , Villet, Martin H , Dadour, I R
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6953 , http://hdl.handle.net/10962/d1011986
- Description: One major aspect of research in forensic entomology is the investigation of molecular techniques for the accurate identification of insects. Studies to date have addressed the corpse fauna of many geographical regions, but generally neglected the southern African calliphorid species. In this study, forensically significant calliphorids from South Africa, Swaziland, Botswana and Zimbabwe and Australia were sequenced over an 1167 base pair region of the COI gene. Phylogenetic analysis was performed to examine the ability of the region to resolve species identities and taxonomic relationships between species. Analyses by neighbour-joining, maximum parsimony and maximum likelihood methods all showed the potential of this region to provide the necessary species-level identifications for application to post-mortem interval (PMI) estimation; however, higher level taxonomic relationships did vary according to method of analysis. Intraspecific variation was also considered in relation to determining suitable maximum levels of variation to be expected during analysis. Individuals of some species in the study represented populations from both South Africa and the east coast of Australia, yet maximum intraspecific variation over this gene region was calculated at 0.8%, with minimum interspecific variation at 3%, indicating distinct ranges of variation to be expected at intra- and interspecific levels. This region therefore appears to provide southern African forensic entomologists with a new technique for providing accurate identification for application to estimation of PMI.
- Full Text:
- Date Issued: 2003
- Authors: Harvey, M L , Mansell, M W , Villet, Martin H , Dadour, I R
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6953 , http://hdl.handle.net/10962/d1011986
- Description: One major aspect of research in forensic entomology is the investigation of molecular techniques for the accurate identification of insects. Studies to date have addressed the corpse fauna of many geographical regions, but generally neglected the southern African calliphorid species. In this study, forensically significant calliphorids from South Africa, Swaziland, Botswana and Zimbabwe and Australia were sequenced over an 1167 base pair region of the COI gene. Phylogenetic analysis was performed to examine the ability of the region to resolve species identities and taxonomic relationships between species. Analyses by neighbour-joining, maximum parsimony and maximum likelihood methods all showed the potential of this region to provide the necessary species-level identifications for application to post-mortem interval (PMI) estimation; however, higher level taxonomic relationships did vary according to method of analysis. Intraspecific variation was also considered in relation to determining suitable maximum levels of variation to be expected during analysis. Individuals of some species in the study represented populations from both South Africa and the east coast of Australia, yet maximum intraspecific variation over this gene region was calculated at 0.8%, with minimum interspecific variation at 3%, indicating distinct ranges of variation to be expected at intra- and interspecific levels. This region therefore appears to provide southern African forensic entomologists with a new technique for providing accurate identification for application to estimation of PMI.
- Full Text:
- Date Issued: 2003
Potter's fingerprints: some prehistoric southern African utilityware in an intimate light.
- Authors: Steele, John
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/945 , vital:30070
- Description: Extensive archaeological excavations in southern Africa during the past century have revealed a richly described heritage of widely distributed First-Millennium (C.E.) Agriculturist ceramics. In viewing both artefacts and assessments thereof it can be observed that ways of thinking shape ways of seeing, and explanations ofwhat is seen. Thus, because conceptual frameworks are inseparable from what is observed and explanations that result, consideration is given to some particular mindsets that have led to recent theories concenring local prehistoric material culture. In conclusion, a brief look at dialogues initiated by some contemporary potters who interrogate cherished lifeways and belief systems serve to elucidate current trends towards finding meaning in prehistoric southern African ceramics.
- Full Text:
- Date Issued: 2003
- Authors: Steele, John
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: http://hdl.handle.net/11260/945 , vital:30070
- Description: Extensive archaeological excavations in southern Africa during the past century have revealed a richly described heritage of widely distributed First-Millennium (C.E.) Agriculturist ceramics. In viewing both artefacts and assessments thereof it can be observed that ways of thinking shape ways of seeing, and explanations ofwhat is seen. Thus, because conceptual frameworks are inseparable from what is observed and explanations that result, consideration is given to some particular mindsets that have led to recent theories concenring local prehistoric material culture. In conclusion, a brief look at dialogues initiated by some contemporary potters who interrogate cherished lifeways and belief systems serve to elucidate current trends towards finding meaning in prehistoric southern African ceramics.
- Full Text:
- Date Issued: 2003
Seasonal phenology of the diamondback moth, Plutella xylostella (L.), (Lepidoptera: Plutellidae), and its parasitoids on canola, Brassica napus (L.), in Gauteng province, South Africa
- Mosiane, S M, Kfir, R, Villet, Martin H
- Authors: Mosiane, S M , Kfir, R , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6856 , http://hdl.handle.net/10962/d1011139
- Description: Canola, Brassica napus L. (Brassicaceae), is a relativelynewcrop in SouthAfrica. Several insect pests, including diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), that attack cruciferous vegetables, also attack canola. The aims of this study were to determine the seasonal phenology of P. xylostella populations on canola, and the composition, relative abundance and seasonal phenology of parasitoids attacking P. xylostella on this crop. Diamondback moth adults were monitored with synthetic sex-pheromone traps. Larval and pupal populations of P. xylostella were monitored weekly for three years at Bapsfontein and Rietondale in Gauteng province. Samples of diamondback moth larvae, pupae and parasitoid cocoons were collected and transported to the laboratory. Parasitoids that emerged were identified and their incidence recorded. Berlese funnel catches were used as an indicator of the accuracy of the visual counts. The infestation level of P. xylostella larvae was high from May to August at Rietondale, while at Bapsfontein it was high from September to December. There was a high correlation (r=0.79, P<0.001) between pheromone trap catches and subsequent larval infestations at Bapsfontein. The pheromone traps indicated that diamondback moth adults were present throughout the year. Berlese funnel catches indicated that a large number of larvae, especially first instars, were overlooked during visual plant scouting. Parasitism rates were often very high, reaching 90–100 %. The following parasitoids were recorded from field-collected P. xylostella: the larval parasitoids Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) and Apanteles halfordi Ullyett (Hymenoptera: Braconidae), the larval/pupal parasitoids Diadegma mollipla (Holmgren) (Hymenoptera: Ichneumonidae) and Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae), the pupal parasitoid Diadromus collaris (Gravenhorst) (Hymenoptera: Ichneumonidae), and the hyperparasitoids Mesochorus sp. (Hymenoptera: Ichneumonidae) and Pteromalus sp. (Hymenoptera: Pteromalidae). Cotesia plutellae was the most abundant parasitoid throughout the study.
- Full Text:
- Date Issued: 2003
- Authors: Mosiane, S M , Kfir, R , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6856 , http://hdl.handle.net/10962/d1011139
- Description: Canola, Brassica napus L. (Brassicaceae), is a relativelynewcrop in SouthAfrica. Several insect pests, including diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), that attack cruciferous vegetables, also attack canola. The aims of this study were to determine the seasonal phenology of P. xylostella populations on canola, and the composition, relative abundance and seasonal phenology of parasitoids attacking P. xylostella on this crop. Diamondback moth adults were monitored with synthetic sex-pheromone traps. Larval and pupal populations of P. xylostella were monitored weekly for three years at Bapsfontein and Rietondale in Gauteng province. Samples of diamondback moth larvae, pupae and parasitoid cocoons were collected and transported to the laboratory. Parasitoids that emerged were identified and their incidence recorded. Berlese funnel catches were used as an indicator of the accuracy of the visual counts. The infestation level of P. xylostella larvae was high from May to August at Rietondale, while at Bapsfontein it was high from September to December. There was a high correlation (r=0.79, P<0.001) between pheromone trap catches and subsequent larval infestations at Bapsfontein. The pheromone traps indicated that diamondback moth adults were present throughout the year. Berlese funnel catches indicated that a large number of larvae, especially first instars, were overlooked during visual plant scouting. Parasitism rates were often very high, reaching 90–100 %. The following parasitoids were recorded from field-collected P. xylostella: the larval parasitoids Cotesia plutellae (Kurdjumov) (Hymenoptera: Braconidae) and Apanteles halfordi Ullyett (Hymenoptera: Braconidae), the larval/pupal parasitoids Diadegma mollipla (Holmgren) (Hymenoptera: Ichneumonidae) and Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae), the pupal parasitoid Diadromus collaris (Gravenhorst) (Hymenoptera: Ichneumonidae), and the hyperparasitoids Mesochorus sp. (Hymenoptera: Ichneumonidae) and Pteromalus sp. (Hymenoptera: Pteromalidae). Cotesia plutellae was the most abundant parasitoid throughout the study.
- Full Text:
- Date Issued: 2003
Thermal responses in some Eastern Cape African Cicadas (Hemiptera: Cicadidae)
- Sanborn, Allen F, Phillips, P K, Villet, Martin H
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6918 , http://hdl.handle.net/10962/d1011881
- Description: Thermal responses were measured in cicadas collected in the Eastern Cape Province of South Africa. The thermal responses of 22 species from 5 biomes were determined. Shade-seeking temperature was the most variable and related to the various biomes. Mean shade-seeking temperature was greatest for species inhabiting the thicket biome and lowest for species inhabiting the forest biome. The animals that live in the thicket biome may adapt to the greater thermal stress to take advantage of a habitat that permits lower predation pressure. There is a correlation between body size and shade-seeking temperatures with smaller species exhibiting lower thermal responses within a particular habitat. This may be related to the greater heat exchange in smaller species. Heat torpor temperatures did not differ between the various biomes.
- Full Text:
- Date Issued: 2003
- Authors: Sanborn, Allen F , Phillips, P K , Villet, Martin H
- Date: 2003
- Language: English
- Type: text , Article
- Identifier: vital:6918 , http://hdl.handle.net/10962/d1011881
- Description: Thermal responses were measured in cicadas collected in the Eastern Cape Province of South Africa. The thermal responses of 22 species from 5 biomes were determined. Shade-seeking temperature was the most variable and related to the various biomes. Mean shade-seeking temperature was greatest for species inhabiting the thicket biome and lowest for species inhabiting the forest biome. The animals that live in the thicket biome may adapt to the greater thermal stress to take advantage of a habitat that permits lower predation pressure. There is a correlation between body size and shade-seeking temperatures with smaller species exhibiting lower thermal responses within a particular habitat. This may be related to the greater heat exchange in smaller species. Heat torpor temperatures did not differ between the various biomes.
- Full Text:
- Date Issued: 2003