Pseudopolydora species associated with mollusc shells on the south coast of South Africa, with the description of Ps. dayii, sp nov
- Authors: Simon, Carol A
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6875 , http://hdl.handle.net/10962/d1011623
- Description: Two species of the genus Pseudopolydora, Ps. dayii, sp. nov. and Ps. antennata, were associated with gastropods on the south and south-east coasts of South Africa. Pseudopolydora dayii is characterized by prominent post-chaetal notopodial lobes on chaetiger 1 with very long chaetae, a prominent occipital tentacle, having hooded hooks that start on chaetiger 9, branchiae that start on chaetiger 6, stout hooks and lobes placed latero-posteriorly to the hooded hooks in posterior chaetigers. It is a surface-fouler and was found on several species of wild gastropods at four of the five sites sampled and from additional material from the south-west coast and on cultured abalone (Haliotis midae) at a farm on the south-west coast. Three individuals of Ps. antennata were found only with oysters at the easternmost site. This was the first record of this species outside of the Western Cape Province and it is possible that their association with the oysters was fortuitous.
- Full Text:
- Date Issued: 2009
- Authors: Simon, Carol A
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6875 , http://hdl.handle.net/10962/d1011623
- Description: Two species of the genus Pseudopolydora, Ps. dayii, sp. nov. and Ps. antennata, were associated with gastropods on the south and south-east coasts of South Africa. Pseudopolydora dayii is characterized by prominent post-chaetal notopodial lobes on chaetiger 1 with very long chaetae, a prominent occipital tentacle, having hooded hooks that start on chaetiger 9, branchiae that start on chaetiger 6, stout hooks and lobes placed latero-posteriorly to the hooded hooks in posterior chaetigers. It is a surface-fouler and was found on several species of wild gastropods at four of the five sites sampled and from additional material from the south-west coast and on cultured abalone (Haliotis midae) at a farm on the south-west coast. Three individuals of Ps. antennata were found only with oysters at the easternmost site. This was the first record of this species outside of the Western Cape Province and it is possible that their association with the oysters was fortuitous.
- Full Text:
- Date Issued: 2009
Basic Chemistry: PAC 113F
- Authors: Soyaya, S.M , Mbentse, J Z
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:17834 , http://hdl.handle.net/10353/d1010388
- Description: Basic Chemistry: PAC 113F, supplementary degree examination June 2011.
- Full Text: false
- Date Issued: 2011-06
- Authors: Soyaya, S.M , Mbentse, J Z
- Date: 2011-06
- Language: English
- Type: Examination paper
- Identifier: vital:17834 , http://hdl.handle.net/10353/d1010388
- Description: Basic Chemistry: PAC 113F, supplementary degree examination June 2011.
- Full Text: false
- Date Issued: 2011-06
Gender and popular imaginaries in Africa:
- Spencer, Lynda G, Ligaga, Dina, Musila, Grace
- Authors: Spencer, Lynda G , Ligaga, Dina , Musila, Grace
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138860 , vital:37679 , DOI: 10.1080/10130950.2018.1526467
- Description: If we accept that many Africans’ social perceptions on a range of questions, including gender, are shaped by popular cultural productions which retain a keen pulse on the everyday, then it is important to reflect on the interface between gender and popular imaginaries. The debate on the definition of the ‘popular’ remains an open one with multiple interpretations and categories. This contestation in itself gestures towards popular culture’s inclination for ambiguity and slipperiness. As Karin Barber (2018:13) reminds us, the popular constitutes “expressive forms that are constantly emergent, ephemeral, embedded in daily life, given to extraordinary bursts of activity and rapid transformation”. For George Ogola, popular cultural forms “engage with and subject the polity to constant critique through informal but widely recognised forms of censure” (2017:2). In this special issue, we use popular imaginaries to mean the range of cultural productions, platforms, and interactions between consumers and producers - which are often interchangeable - that capture the material, the affective, as inflected and refracted in different texts, contexts and platforms.
- Full Text:
- Date Issued: 2018
- Authors: Spencer, Lynda G , Ligaga, Dina , Musila, Grace
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/138860 , vital:37679 , DOI: 10.1080/10130950.2018.1526467
- Description: If we accept that many Africans’ social perceptions on a range of questions, including gender, are shaped by popular cultural productions which retain a keen pulse on the everyday, then it is important to reflect on the interface between gender and popular imaginaries. The debate on the definition of the ‘popular’ remains an open one with multiple interpretations and categories. This contestation in itself gestures towards popular culture’s inclination for ambiguity and slipperiness. As Karin Barber (2018:13) reminds us, the popular constitutes “expressive forms that are constantly emergent, ephemeral, embedded in daily life, given to extraordinary bursts of activity and rapid transformation”. For George Ogola, popular cultural forms “engage with and subject the polity to constant critique through informal but widely recognised forms of censure” (2017:2). In this special issue, we use popular imaginaries to mean the range of cultural productions, platforms, and interactions between consumers and producers - which are often interchangeable - that capture the material, the affective, as inflected and refracted in different texts, contexts and platforms.
- Full Text:
- Date Issued: 2018
Taxation: ATV 311E & ATA 311E
- Authors: Stevens, N , Krug, L
- Date: 2009-06
- Subjects: Tax accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17407 , http://hdl.handle.net/10353/d1009771
- Description: Examination on Taxation: ATV 311E & ATA 311E - June Exams 2009
- Full Text:
- Date Issued: 2009-06
- Authors: Stevens, N , Krug, L
- Date: 2009-06
- Subjects: Tax accounting
- Language: English
- Type: Examination paper
- Identifier: vital:17407 , http://hdl.handle.net/10353/d1009771
- Description: Examination on Taxation: ATV 311E & ATA 311E - June Exams 2009
- Full Text:
- Date Issued: 2009-06
High genetic diversity and limited spatial structure in an endangered, endemic South African sparid, the red steenbras Petrus rupestris:
- Tang, Wei, Qiu, Yuanyuan, Li, Xiaonan, Soy, Rodah C, Mack, John, Nyokong, Tebello
- Authors: Tang, Wei , Qiu, Yuanyuan , Li, Xiaonan , Soy, Rodah C , Mack, John , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160390 , vital:40441 , DOI: 10.6060/mhc200183l
- Description: Earth-abundant first row transition metal corrole complexes have played an important role in fundamental research due to their unique molecular structures and attractive properties. In comparison to porphyrins, corroles have three inner N-H protons and are ring-contracted with a smaller macrocyclic cavity. First row transition metal corroles have been widely used as effective electrochemical catalysts for small molecule activations, such as hydrogen evolution, oxygen reduction/evolution and CO2 reduction reactions (HERs, ORRs/OERs and CO2 RRs) through homogenous and/or heterogenous prodecures. Several strategies have been used to modulate the catalytic efficiency of synthetic metallocorroles.
- Full Text:
- Date Issued: 2020
- Authors: Tang, Wei , Qiu, Yuanyuan , Li, Xiaonan , Soy, Rodah C , Mack, John , Nyokong, Tebello
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160390 , vital:40441 , DOI: 10.6060/mhc200183l
- Description: Earth-abundant first row transition metal corrole complexes have played an important role in fundamental research due to their unique molecular structures and attractive properties. In comparison to porphyrins, corroles have three inner N-H protons and are ring-contracted with a smaller macrocyclic cavity. First row transition metal corroles have been widely used as effective electrochemical catalysts for small molecule activations, such as hydrogen evolution, oxygen reduction/evolution and CO2 reduction reactions (HERs, ORRs/OERs and CO2 RRs) through homogenous and/or heterogenous prodecures. Several strategies have been used to modulate the catalytic efficiency of synthetic metallocorroles.
- Full Text:
- Date Issued: 2020
Cytotoxicity of triterpenoids from Clerodendrum glabrum against triple negative breast cancer cells in vitro:
- Teclegeorgish, Zecarias W, Mokgalaka, Ntebogeng S, Vukea, Nyeleti, de la Mare, Jo-Anne, Tembu, Vuyelwa J
- Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
- Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
- Full Text:
- Date Issued: 2020
- Authors: Teclegeorgish, Zecarias W , Mokgalaka, Ntebogeng S , Vukea, Nyeleti , de la Mare, Jo-Anne , Tembu, Vuyelwa J
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161511 , vital:40634 , https://doi.org/10.1016/j.sajb.2020.07.009
- Description: Clerodendrum glabrum is an indigenous medicinal plant that is used to treat cough, cold, sore throat and chest complaints. The stem bark of Clerodendrum glabrum afforded four tritepenoids namely, 3β-olean-12-en-3-yl palmitate (β-amyrin palmitate), (1), 3β hydroxy 5-glutinene (glutinol), (2), 3β-lup-20(29)-en-3-palmitate (Lupeol-3-palmitate), (3), 3β-lup-20(29)-en-3-ol (lupeol) (4) and one common phytosterol (stigmasterol) (5). The structures were established on the basis of their spectroscopic analysis. The compounds were screened for cytotoxicity against the HCC70 triple negative breast cancer (TNBC), MCF-7 hormone receptor positive breast cancer and MCF-12A non-cancerous mammary epithelial cell lines.
- Full Text:
- Date Issued: 2020
Compounds isolation and biological activities of Piptadeniastrum africanum (hook. f.) Brennan (Fabaceae) roots:
- Teinkela, Jean E M, Noundou, Xavier S, Mimba, Jeanne E Z, Meyer, Franck, Tabouguia, Octavie M, Nguedia, Jules C A, Hoppe, Heinrich C, Krause, Rui W M, Wintjens, René, Azebaze, Anatole G B
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
- Authors: Teinkela, Jean E M , Noundou, Xavier S , Mimba, Jeanne E Z , Meyer, Franck , Tabouguia, Octavie M , Nguedia, Jules C A , Hoppe, Heinrich C , Krause, Rui W M , Wintjens, René , Azebaze, Anatole G B
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150084 , vital:38938 , https://doi.org/10.1016/j.jep.2020.112716
- Description: The dicotyledonous plant Piptadeniastrum africanum (hook.f.) Brennan (Fabaceae) is used in traditional medicine to treat various human complaints including bronchitis, coughing, urino-genital ailments, meningitis, abdominal pain, treatment of wounds, malaria and gastrointestinal ailments, and is used as a purgative and worm expeller. The present study describes the phytochemical investigation and the determination of the antimicrobial, antiplasmodial and antitrypanosomal activities of crude extract, fractions and compounds extracted from Piptadeniastrum africanum roots.
- Full Text:
- Date Issued: 2020
Aesthetic autonomy at the border:
- Authors: Tello, Verónica
- Date: 2018
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/146244 , vital:38508 , ISBN 9781786606860
- Description: Book abstract. Every politics is an aesthetic. If necropolitics is the (accelerated) politics of what is usually referred to as the ‘apolitical age’, what are its manoeuvres, temporalities, intensities, textures, and tipping points? Bypassing revelatory and reconstructionist approaches – the tendency of which is to show that a particular site or practice is necropolitical by bringing its genealogy into evidence – this collection of essays by artist-philosophers and theorist curators articulates the pre-perceptual working of necropolitics through a focus on the senses, assignments of energy, attitudes, cognitive processes, and discursive frameworks.
- Full Text:
- Date Issued: 2018
- Authors: Tello, Verónica
- Date: 2018
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/146244 , vital:38508 , ISBN 9781786606860
- Description: Book abstract. Every politics is an aesthetic. If necropolitics is the (accelerated) politics of what is usually referred to as the ‘apolitical age’, what are its manoeuvres, temporalities, intensities, textures, and tipping points? Bypassing revelatory and reconstructionist approaches – the tendency of which is to show that a particular site or practice is necropolitical by bringing its genealogy into evidence – this collection of essays by artist-philosophers and theorist curators articulates the pre-perceptual working of necropolitics through a focus on the senses, assignments of energy, attitudes, cognitive processes, and discursive frameworks.
- Full Text:
- Date Issued: 2018
Distributed Web Computing: CSC 523
- Authors: Thinyane, M , Vogts, D
- Date: 2010-11
- Language: English
- Type: Examination paper
- Identifier: vital:17786 , http://hdl.handle.net/10353/d1010326
- Description: Distributed Web Computing: CSC 523, honours examination November 2010.
- Full Text: false
- Date Issued: 2010-11
- Authors: Thinyane, M , Vogts, D
- Date: 2010-11
- Language: English
- Type: Examination paper
- Identifier: vital:17786 , http://hdl.handle.net/10353/d1010326
- Description: Distributed Web Computing: CSC 523, honours examination November 2010.
- Full Text: false
- Date Issued: 2010-11
Un Langage, des Visions, une Passerelle:
- Authors: Tshilumba Mukendi, J S
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/146177 , vital:38502 , ISBN 9789074816496 , https://books.google.co.za/books?id=QDSdAQAACAAJanddq=Creer+en+postcolonie:+Voix+et+dissidences+belgo-congolaise+2010-2015andhl=enandsa=Xandved=0ahUKEwjts_Si_b_pAhXvShUIHWXwCd4Q6AEIJzAA
- Description: Book abstract. The authors and artists (Baloji, Toma Muteba Luntumbue, Nganji Laeh, Nina Miskina, Joëlle Sambi, Sarah Arens, Heleen Debeuckelaere, Bénédicte Kumbi ...) who contributed to the work to debate the Belgian postcolonial question and it will be punctuated by poetic and musical stops.
- Full Text:
- Date Issued: 2016
- Authors: Tshilumba Mukendi, J S
- Date: 2016
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/146177 , vital:38502 , ISBN 9789074816496 , https://books.google.co.za/books?id=QDSdAQAACAAJanddq=Creer+en+postcolonie:+Voix+et+dissidences+belgo-congolaise+2010-2015andhl=enandsa=Xandved=0ahUKEwjts_Si_b_pAhXvShUIHWXwCd4Q6AEIJzAA
- Description: Book abstract. The authors and artists (Baloji, Toma Muteba Luntumbue, Nganji Laeh, Nina Miskina, Joëlle Sambi, Sarah Arens, Heleen Debeuckelaere, Bénédicte Kumbi ...) who contributed to the work to debate the Belgian postcolonial question and it will be punctuated by poetic and musical stops.
- Full Text:
- Date Issued: 2016
Education Studies 2(A): ECA 421
- Vye, Z, Macanda, M A A, Sao, L, Madubedube, M, Jordaan, D C
- Authors: Vye, Z , Macanda, M A A , Sao, L , Madubedube, M , Jordaan, D C
- Date: 2010-01
- Subjects: Education
- Language: English
- Type: Examination paper
- Identifier: vital:17284 , http://hdl.handle.net/10353/d1010030
- Description: Examination on Education Studies 2(A): ECA 421, January 2010.
- Full Text: false
- Date Issued: 2010-01
- Authors: Vye, Z , Macanda, M A A , Sao, L , Madubedube, M , Jordaan, D C
- Date: 2010-01
- Subjects: Education
- Language: English
- Type: Examination paper
- Identifier: vital:17284 , http://hdl.handle.net/10353/d1010030
- Description: Examination on Education Studies 2(A): ECA 421, January 2010.
- Full Text: false
- Date Issued: 2010-01
Role of percutaneous penetration enhancers
- Walker, Roderick B, Smith, Eric W
- Authors: Walker, Roderick B , Smith, Eric W
- Date: 1996
- Language: English
- Type: text , Article
- Identifier: vital:6446 , http://hdl.handle.net/10962/d1006633
- Description: It is clear that scientists are now only beginning to comprehend the complexity of transdermal drug delivery. Elucidation of the biochemical composition and functioning of the intrinsic diffusional barrier of the stratum corneum has prompted investigation of chemical and physical means of enhancing the percutaneous penetration of poorly absorbed drugs. Chemical enhancers that aid absorption of co-administered moieties are currently believed to improve solubility within the stratum corneum or increase lipid fluidity of the intracellular bilayers. Alternatively,the use of ionto- or phonophoresis may facilitate the absorption of some drug molecules by physical alteration of the barrier. The role of penetration enhancer inclusion in topical formulations has been well documented and will undoubtedly, in the future, permit the delivery of broader classes of drugs through the stratum corneum.
- Full Text:
- Date Issued: 1996
- Authors: Walker, Roderick B , Smith, Eric W
- Date: 1996
- Language: English
- Type: text , Article
- Identifier: vital:6446 , http://hdl.handle.net/10962/d1006633
- Description: It is clear that scientists are now only beginning to comprehend the complexity of transdermal drug delivery. Elucidation of the biochemical composition and functioning of the intrinsic diffusional barrier of the stratum corneum has prompted investigation of chemical and physical means of enhancing the percutaneous penetration of poorly absorbed drugs. Chemical enhancers that aid absorption of co-administered moieties are currently believed to improve solubility within the stratum corneum or increase lipid fluidity of the intracellular bilayers. Alternatively,the use of ionto- or phonophoresis may facilitate the absorption of some drug molecules by physical alteration of the barrier. The role of penetration enhancer inclusion in topical formulations has been well documented and will undoubtedly, in the future, permit the delivery of broader classes of drugs through the stratum corneum.
- Full Text:
- Date Issued: 1996
A comparison of three techniques for fluorochrome marking of juvenile Clarias gariepinus otoliths
- Wartenberg, Reece, Booth, Anthony J, Weyl, Olaf L F
- Authors: Wartenberg, Reece , Booth, Anthony J , Weyl, Olaf L F
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123520 , vital:35450 , https://doi.10.3377/004.046.0119
- Description: African sharptooth catfish, Clarias gariepinus (Burchell 1822), is widely distributed with a natural range that extends from southern Turkey to the Orange River, South Africa (Skelton 2001). In addition to translocations within its southerly range (Cambray 2003), Cambray (2005) noted that as a result of poor aquaculture practices and introductions from a number of unknown sources, C. gariepinus has now invaded South America, Europe, Asia, and Australia. Its life history characteristics include a fast growth rate to a maximum length of 1300mmtotal length (TL) (Bruton 1976), a high fecundity, an omnivorous diet and the ability to breathe air (de Moor & Bruton 1988; Cambray 2003). Understanding the biology and population dynamics of this invader would assist in its management and possibly eradication.
- Full Text:
- Date Issued: 2011
- Authors: Wartenberg, Reece , Booth, Anthony J , Weyl, Olaf L F
- Date: 2011
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123520 , vital:35450 , https://doi.10.3377/004.046.0119
- Description: African sharptooth catfish, Clarias gariepinus (Burchell 1822), is widely distributed with a natural range that extends from southern Turkey to the Orange River, South Africa (Skelton 2001). In addition to translocations within its southerly range (Cambray 2003), Cambray (2005) noted that as a result of poor aquaculture practices and introductions from a number of unknown sources, C. gariepinus has now invaded South America, Europe, Asia, and Australia. Its life history characteristics include a fast growth rate to a maximum length of 1300mmtotal length (TL) (Bruton 1976), a high fecundity, an omnivorous diet and the ability to breathe air (de Moor & Bruton 1988; Cambray 2003). Understanding the biology and population dynamics of this invader would assist in its management and possibly eradication.
- Full Text:
- Date Issued: 2011
Conspecific alarm cue sensitivity by the estuarine calanoid copepod, Paracartia longipatella
- Wasserman, Ryan J, Kramer, Rachel, Vink, Tim J F, Froneman, P William
- Authors: Wasserman, Ryan J , Kramer, Rachel , Vink, Tim J F , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68062 , vital:29194 , https://doi.org/10.1111/aec.12135
- Description: Publisher version , Sensitivity to chemical cues associated with predation threat has been well observed in many freshwater zooplankters, yet few studies have highlighted such sensitivity in eury- and stenohaline metazoans. We aimed to assess sensitivity to conspecific chemical alarm cues in the estuarine copepod, Paracartia longipatella. Alarm cues associated with predation have been shown to have population level effects on certain zooplanktonic species. As such, we assessed the occurrence of such effects on population dynamics of P.longipatella over a 12 day period. Using experimental in situ mesocosms, we compared P.longipatella adult, copepodite and nauplii numbers between three treatments; one inoculated with conspecific alarm cues, one containing direct predation pressure (zooplanktivorous fish), and a control treatment containing no predation threat. Trends in population abundances were similar between the direct predation and alarm cue treatments for the six days of the experiment, decreasing in abundance. During the latter half of the study, however, P.longipatella abundances in the alarm cue treatment increased, while those in the presence of direct predation continued to decrease. In the treatment absent of any predation threat, P.longipatella abundances increased consistently over time for the duration of the study. We suggest that P.longipatella are indeed sensitive to conspecific alarm cues associated with predation threat. Furthermore, we propose that prolonged exposure to conspecific alarm cues in the absence of any real threat results in a reduction in sensitive to these cues.
- Full Text: false
- Date Issued: 2014
- Authors: Wasserman, Ryan J , Kramer, Rachel , Vink, Tim J F , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68062 , vital:29194 , https://doi.org/10.1111/aec.12135
- Description: Publisher version , Sensitivity to chemical cues associated with predation threat has been well observed in many freshwater zooplankters, yet few studies have highlighted such sensitivity in eury- and stenohaline metazoans. We aimed to assess sensitivity to conspecific chemical alarm cues in the estuarine copepod, Paracartia longipatella. Alarm cues associated with predation have been shown to have population level effects on certain zooplanktonic species. As such, we assessed the occurrence of such effects on population dynamics of P.longipatella over a 12 day period. Using experimental in situ mesocosms, we compared P.longipatella adult, copepodite and nauplii numbers between three treatments; one inoculated with conspecific alarm cues, one containing direct predation pressure (zooplanktivorous fish), and a control treatment containing no predation threat. Trends in population abundances were similar between the direct predation and alarm cue treatments for the six days of the experiment, decreasing in abundance. During the latter half of the study, however, P.longipatella abundances in the alarm cue treatment increased, while those in the presence of direct predation continued to decrease. In the treatment absent of any predation threat, P.longipatella abundances increased consistently over time for the duration of the study. We suggest that P.longipatella are indeed sensitive to conspecific alarm cues associated with predation threat. Furthermore, we propose that prolonged exposure to conspecific alarm cues in the absence of any real threat results in a reduction in sensitive to these cues.
- Full Text: false
- Date Issued: 2014
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
National count: number of votes cast: provisional Western Cape figures
- Authors: Western Cape Province
- Date: 19--?
- Subjects: South Africa -- Politics and government -- 1989- , Voting -- South Africa -- Western Cape
- Language: eng
- Type: text , book
- Identifier: http://hdl.handle.net/10962/77002 , vital:30654
- Full Text:
- Date Issued: 19--?
- Authors: Western Cape Province
- Date: 19--?
- Subjects: South Africa -- Politics and government -- 1989- , Voting -- South Africa -- Western Cape
- Language: eng
- Type: text , book
- Identifier: http://hdl.handle.net/10962/77002 , vital:30654
- Full Text:
- Date Issued: 19--?
Use of a non-hepatic cell line highlights limitations associated with cell-based assessment of metabolically induced toxicity:
- Weyers, Carli, Dingle, Laura M K, Wilhelmi, Brendan S, Edkins, Adrienne L, Veale, Clinton G
- Authors: Weyers, Carli , Dingle, Laura M K , Wilhelmi, Brendan S , Edkins, Adrienne L , Veale, Clinton G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160290 , vital:40431 , DOI: 10.1080/01480545.2019.1585869
- Description: Metabolically induced drug-toxicity is a major cause of drug failure late in drug optimization phases. Accordingly, in vitro metabolic profiling of compounds is being introduced at earlier stages of the drug discovery pipeline. An increasingly common method to obtain these profiles is through overexpression of key CYP450 metabolic enzymes in immortalized liver cells, to generate competent hepatocyte surrogates. Enhanced cytotoxicity is presumed to be due to toxic metabolite production via the overexpressed enzyme. However, metabolically induced toxicity is a complex multi-parameter phenomenon and the potential background contribution to metabolism arising from the use of liver cells which endogenously express CYP450 isoforms is consistently overlooked. In this study, we sought to reduce the potential background interference by applying this methodology in kidney-derived HEK293 cells which lack endogenous CYP450 expression.
- Full Text:
- Date Issued: 2020
- Authors: Weyers, Carli , Dingle, Laura M K , Wilhelmi, Brendan S , Edkins, Adrienne L , Veale, Clinton G
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160290 , vital:40431 , DOI: 10.1080/01480545.2019.1585869
- Description: Metabolically induced drug-toxicity is a major cause of drug failure late in drug optimization phases. Accordingly, in vitro metabolic profiling of compounds is being introduced at earlier stages of the drug discovery pipeline. An increasingly common method to obtain these profiles is through overexpression of key CYP450 metabolic enzymes in immortalized liver cells, to generate competent hepatocyte surrogates. Enhanced cytotoxicity is presumed to be due to toxic metabolite production via the overexpressed enzyme. However, metabolically induced toxicity is a complex multi-parameter phenomenon and the potential background contribution to metabolism arising from the use of liver cells which endogenously express CYP450 isoforms is consistently overlooked. In this study, we sought to reduce the potential background interference by applying this methodology in kidney-derived HEK293 cells which lack endogenous CYP450 expression.
- Full Text:
- Date Issued: 2020
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
Sectioned or whole otoliths? A global review of hard structure preparation techniques used in ageing sparid fishes
- Winkler, Alexander C, Duncan, Murray I, Farthing, Matthew W, Potts, Warren M
- Authors: Winkler, Alexander C , Duncan, Murray I , Farthing, Matthew W , Potts, Warren M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126733 , vital:35917 , https://doi.10.1007/s11160-019-09571-1
- Description: While otoliths are considered the most reliable structure to accurately age fish, a variety of otolith preparation techniques are available, which have consequences on the otolith’s optical properties and therefore interpretation of growth bands. Recently, numerous studies from a variety of authors have criticised the use of whole otoliths in ageing sparids with sectioned otoliths subsequently acknowledged as the most reliable preparation technique. Despite this criticism; ageing data is still being generated from whole otoliths and other unreliable structures such as scales. In an attempt to understand the severity of this issue we conducted a global literature review of otolith preparation protocols used for sparids. We identified global spatial inconsistencies in otolith preparation techniques with some regions predominately using methods other than sectioned otoliths to age sparids. The review highlights the need for a standardisation of otolith preparation methods and a move towards the use of sectioned otoliths, or at least valid support where alternative structures or preparation techniques are used. Given that large numbers of studies have been conducted on whole otoliths in certain regions, it may be necessary to revaluate the existing growth parameters to ensure that accurate information is incorporated into management structures.
- Full Text:
- Date Issued: 2019
- Authors: Winkler, Alexander C , Duncan, Murray I , Farthing, Matthew W , Potts, Warren M
- Date: 2019
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126733 , vital:35917 , https://doi.10.1007/s11160-019-09571-1
- Description: While otoliths are considered the most reliable structure to accurately age fish, a variety of otolith preparation techniques are available, which have consequences on the otolith’s optical properties and therefore interpretation of growth bands. Recently, numerous studies from a variety of authors have criticised the use of whole otoliths in ageing sparids with sectioned otoliths subsequently acknowledged as the most reliable preparation technique. Despite this criticism; ageing data is still being generated from whole otoliths and other unreliable structures such as scales. In an attempt to understand the severity of this issue we conducted a global literature review of otolith preparation protocols used for sparids. We identified global spatial inconsistencies in otolith preparation techniques with some regions predominately using methods other than sectioned otoliths to age sparids. The review highlights the need for a standardisation of otolith preparation methods and a move towards the use of sectioned otoliths, or at least valid support where alternative structures or preparation techniques are used. Given that large numbers of studies have been conducted on whole otoliths in certain regions, it may be necessary to revaluate the existing growth parameters to ensure that accurate information is incorporated into management structures.
- Full Text:
- Date Issued: 2019