Colonisation and community structure of benthic diatoms on artificial substrates following a major flood event: a case of the Kowie River (Eastern Cape, South Africa)
- Dalu, Tatenda, Froneman, P William, Chari, Lenin D, Richoux, Nicole B
- Authors: Dalu, Tatenda , Froneman, P William , Chari, Lenin D , Richoux, Nicole B
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143357 , vital:38239 , http://dx.doi.org/10.4314/wsa.v40i3.10
- Description: A major flooding event that occurred during October–November 2012 caused major changes in the Kowie River hydromorphology and aquatic communities. The aim of our study was to identify the environmental variables that structure riverine benthic diatom communities at upstream and downstream locations 25 km apart on the Kowie River, South Africa. This was undertaken using tiles as artificial substrates so that we could study how the communities developed after the flood disturbance. The diatom community structure was assessed over a 28-day period following a flood event in October 2012. The Mann Whitney test indicated that there was a statistically significant difference (p 0.05) in total dissolved solids, salinity, pH and oxygen reduction potential between the two sites. In total, 58 diatom species belonging to 30 genera were identified over the 28-day study.
- Full Text:
- Date Issued: 2014
- Authors: Dalu, Tatenda , Froneman, P William , Chari, Lenin D , Richoux, Nicole B
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/143357 , vital:38239 , http://dx.doi.org/10.4314/wsa.v40i3.10
- Description: A major flooding event that occurred during October–November 2012 caused major changes in the Kowie River hydromorphology and aquatic communities. The aim of our study was to identify the environmental variables that structure riverine benthic diatom communities at upstream and downstream locations 25 km apart on the Kowie River, South Africa. This was undertaken using tiles as artificial substrates so that we could study how the communities developed after the flood disturbance. The diatom community structure was assessed over a 28-day period following a flood event in October 2012. The Mann Whitney test indicated that there was a statistically significant difference (p 0.05) in total dissolved solids, salinity, pH and oxygen reduction potential between the two sites. In total, 58 diatom species belonging to 30 genera were identified over the 28-day study.
- Full Text:
- Date Issued: 2014
Comparison between base metals and platinum group metals in nitrogen, M codoped TiO 2 (M= Fe, Cu, Pd, Os) for photocatalytic removal of an organic dye in water
- Kuvarega, Alex T, Mamba, Bhekie B, Krause, Rui W M
- Authors: Kuvarega, Alex T , Mamba, Bhekie B , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125129 , vital:35734 , https://doi.org/10.1155/2014/962102
- Description: The photocatalytic performance of a number of nonmetal and metal codoped TiO2 for the degradation of eosin yellow under simulated solar radiation was investigated. The synthesised materials were characterised by FTIR, Raman spectroscopy, XRD, DRUV-Vis, SEM, and TEM.The N, metal codoped TiO2 containing 0.5 wt.% of the metal consisted mainly of the anatase phase, with a particle size range of 15–28 nm. The particles were largely spherical and shifted the absorption edge well into the visible region. Band gap reduction was more pronounced for the N, PGM codoped TiO2 compared to N, base metal codoped samples. Codoping led to an enhancement in the photocatalytic activity of the materials for the degradation of eosin yellow. N, Pd codoped TiO2 was the most effective photocatalyst (99.9% dye removal) while N, Cu codoped TiO2 showed the least activity (25.5% removal). The mechanism for the photocatalytic enhancement was proposed on the basis of formation of an electron deficient Schottky barrier at the semiconductor-metal interface, which acts as an electron sink and thus retards electron-hole recombination. It was shown that the ability of the photocatalyst to degrade the dye depends on the nature and type of the metal dopant in the codoped TiO2 system.
- Full Text:
- Date Issued: 2014
- Authors: Kuvarega, Alex T , Mamba, Bhekie B , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125129 , vital:35734 , https://doi.org/10.1155/2014/962102
- Description: The photocatalytic performance of a number of nonmetal and metal codoped TiO2 for the degradation of eosin yellow under simulated solar radiation was investigated. The synthesised materials were characterised by FTIR, Raman spectroscopy, XRD, DRUV-Vis, SEM, and TEM.The N, metal codoped TiO2 containing 0.5 wt.% of the metal consisted mainly of the anatase phase, with a particle size range of 15–28 nm. The particles were largely spherical and shifted the absorption edge well into the visible region. Band gap reduction was more pronounced for the N, PGM codoped TiO2 compared to N, base metal codoped samples. Codoping led to an enhancement in the photocatalytic activity of the materials for the degradation of eosin yellow. N, Pd codoped TiO2 was the most effective photocatalyst (99.9% dye removal) while N, Cu codoped TiO2 showed the least activity (25.5% removal). The mechanism for the photocatalytic enhancement was proposed on the basis of formation of an electron deficient Schottky barrier at the semiconductor-metal interface, which acts as an electron sink and thus retards electron-hole recombination. It was shown that the ability of the photocatalyst to degrade the dye depends on the nature and type of the metal dopant in the codoped TiO2 system.
- Full Text:
- Date Issued: 2014
Comparison of fluorophore and peroxidase labeled aptamer assays for MUC1 detection in cancer cells
- Flanagan, Shane, Limson, Janice, Fogel, Ronen
- Authors: Flanagan, Shane , Limson, Janice , Fogel, Ronen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431076 , vital:72742 , xlink:href="10.1109/BioCAS.2014.6981720"
- Description: Aptamers hold great promise for cancer diagnosis and therapy. Several biosensors incorporate aptamers as biorecognition elements for tumor markers although few evaluate their detection in a native conformation and cellular micro-environment. In this study, fluorophore and peroxidase labeled aptamer configurations were compared for the detection of MCF7 breast and SW620 colon cancer cell lines expressing the tumor marker MUC1. Fluorescence based detection showed selective binding to the cell lines relative to a nonbinding control sequence with sequence specific binding differences between MUC1 aptamers accredited to variation in the glycosylation state of expressed MUC1. The peroxidase labeled assay showed high detection sensitivity although low binding specificity was observed for the MUC1 aptamers to the cell lines. Results suggest that aptamers susceptible to non specific binding to cells may limit the applicability of enzymatic amplification to improve aptasensor sensitivity.
- Full Text:
- Date Issued: 2014
- Authors: Flanagan, Shane , Limson, Janice , Fogel, Ronen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431076 , vital:72742 , xlink:href="10.1109/BioCAS.2014.6981720"
- Description: Aptamers hold great promise for cancer diagnosis and therapy. Several biosensors incorporate aptamers as biorecognition elements for tumor markers although few evaluate their detection in a native conformation and cellular micro-environment. In this study, fluorophore and peroxidase labeled aptamer configurations were compared for the detection of MCF7 breast and SW620 colon cancer cell lines expressing the tumor marker MUC1. Fluorescence based detection showed selective binding to the cell lines relative to a nonbinding control sequence with sequence specific binding differences between MUC1 aptamers accredited to variation in the glycosylation state of expressed MUC1. The peroxidase labeled assay showed high detection sensitivity although low binding specificity was observed for the MUC1 aptamers to the cell lines. Results suggest that aptamers susceptible to non specific binding to cells may limit the applicability of enzymatic amplification to improve aptasensor sensitivity.
- Full Text:
- Date Issued: 2014
Comparison of the biology of geographically distinct populations of the citrus pest, Thaumatotibia leucotreta (Meyrick)(Lepidoptera: Tortricidae)
- Opoku-Debrah, John K, Hill, Martin P, Knox, Caroline M, Moore, Sean D
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline M , Moore, Sean D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405769 , vital:70204 , xlink:href="https://hdl.handle.net/10520/EJC160246"
- Description: Baculovirus biopesticides are an important component of integrated pest management programmes worldwide. One such example is the Cryptophlebia leucotreta granulovirus (CrleGV) which is used for the control of false codling moth, Thaumatotibia (= Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of citrus and other crops in South Africa. A potential problem associated with constant application of viral biopesticides is the differing susceptibility to the virus observed between different geographic populations of the insect host. This could be related to a number of factors, including biological performance and fitness of the target insect population. This study compared a variety of phenotypic traits between geographically distinct T. leucotreta populations collected from the Addo, Marble Hall, Citrusdal and Nelspruit regions of South Africa, and reared under laboratory conditions for several generations. Traits including pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and developmental time were used as parameters to measure biological performance and fitness. Insects from the Citrusdal region of the Western Cape exhibited significantly lower pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and the longest duration in larval and pupal development compared to the other colonies investigated. This is the first study to report differences in the performance of laboratory reared T. leucotreta from different geographic locations, and the findings may have important implications for the application of viral biopesticides for the control of this pest in South Africa.
- Full Text:
- Date Issued: 2014
- Authors: Opoku-Debrah, John K , Hill, Martin P , Knox, Caroline M , Moore, Sean D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/405769 , vital:70204 , xlink:href="https://hdl.handle.net/10520/EJC160246"
- Description: Baculovirus biopesticides are an important component of integrated pest management programmes worldwide. One such example is the Cryptophlebia leucotreta granulovirus (CrleGV) which is used for the control of false codling moth, Thaumatotibia (= Cryptophlebia) leucotreta (Meyrick) (Lepidoptera: Tortricidae), a pest of citrus and other crops in South Africa. A potential problem associated with constant application of viral biopesticides is the differing susceptibility to the virus observed between different geographic populations of the insect host. This could be related to a number of factors, including biological performance and fitness of the target insect population. This study compared a variety of phenotypic traits between geographically distinct T. leucotreta populations collected from the Addo, Marble Hall, Citrusdal and Nelspruit regions of South Africa, and reared under laboratory conditions for several generations. Traits including pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and developmental time were used as parameters to measure biological performance and fitness. Insects from the Citrusdal region of the Western Cape exhibited significantly lower pupal mass, female fecundity, egg hatch, pupal survival, adult eclosion and the longest duration in larval and pupal development compared to the other colonies investigated. This is the first study to report differences in the performance of laboratory reared T. leucotreta from different geographic locations, and the findings may have important implications for the application of viral biopesticides for the control of this pest in South Africa.
- Full Text:
- Date Issued: 2014
Competition between two aquatic macrophytes, Lagarosiphon major (Ridley) Moss (Hydrocharitaceae) and Myriophyllum spicatum Linnaeus (Haloragaceae) as influenced by substrate sediment and nutrients
- Martin, Grant D, Coetzee, Julie A
- Authors: Martin, Grant D , Coetzee, Julie A
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76925 , vital:30641 , https://doi.org/10.1016/j.aquabot.2013.11.001
- Description: Competition between two globally economic and ecologically important submerged aquatic macrophytes, Lagarosiphon major (Rid.) Moss ex Wager and Myriophyllum spicatum L., was studied in response to growing in different substrate nutrient and sediment treatments. Addition series experiments were conducted with mixed plantings of L. major and M. spicatum grown under two soil nutrient concentrations (high vs. low) and two sediment treatments (sand vs. loam). Competitive ability of the plants was determined using an inverse linear model of the total dry weights as the yield variable. In high nutrient sediment treatments, L. major was the stronger competitor relative to M. spicatum, with one L. major plant being competitively equivalent to 2.5 M. spicatum plants in terms of their respective ability to reduce L. major biomass. In the loam sediment treatments, L. major was an even stronger competitor relative to M. spicatum with one L. major being equivalent to 10 M. spicatum plants. Additionally, L. major had a faster relative growth rate (RGR) than M. spicatum when grown in mixed cultures, a loam sediment type and at both high and low planting densities. The results indicated that L. major is a superior competitor to M. spicatum and that both nutrient and sediment conditions significantly affect the competitive ability of both species. The results contribute to the understanding of competition between submerged invasive macrophytes, and provide insight into the establishment and spread of invasive submerged macrophytes.
- Full Text:
- Date Issued: 2014
- Authors: Martin, Grant D , Coetzee, Julie A
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76925 , vital:30641 , https://doi.org/10.1016/j.aquabot.2013.11.001
- Description: Competition between two globally economic and ecologically important submerged aquatic macrophytes, Lagarosiphon major (Rid.) Moss ex Wager and Myriophyllum spicatum L., was studied in response to growing in different substrate nutrient and sediment treatments. Addition series experiments were conducted with mixed plantings of L. major and M. spicatum grown under two soil nutrient concentrations (high vs. low) and two sediment treatments (sand vs. loam). Competitive ability of the plants was determined using an inverse linear model of the total dry weights as the yield variable. In high nutrient sediment treatments, L. major was the stronger competitor relative to M. spicatum, with one L. major plant being competitively equivalent to 2.5 M. spicatum plants in terms of their respective ability to reduce L. major biomass. In the loam sediment treatments, L. major was an even stronger competitor relative to M. spicatum with one L. major being equivalent to 10 M. spicatum plants. Additionally, L. major had a faster relative growth rate (RGR) than M. spicatum when grown in mixed cultures, a loam sediment type and at both high and low planting densities. The results indicated that L. major is a superior competitor to M. spicatum and that both nutrient and sediment conditions significantly affect the competitive ability of both species. The results contribute to the understanding of competition between submerged invasive macrophytes, and provide insight into the establishment and spread of invasive submerged macrophytes.
- Full Text:
- Date Issued: 2014
Conjugates of platinum nanoparticles with gallium tetra–(4-Carboxyphenyl) porphyrin and their use in photodynamic antimicrobial chemotherapy when in solution or embedded in electrospun fiber
- Managa, Muthumuni, Antunes, Edith M, Nyokong, Tebello
- Authors: Managa, Muthumuni , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193791 , vital:45396 , xlink:href="https://doi.org/10.1016/j.poly.2014.03.050"
- Description: The conjugation of Pt nanoparticles with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP) showed greater antimicrobial activity against a gram positive and drug resistant bacteria Staphylococcus aureus, than when the porphyrin was used alone. ClGaTCPP and its conjugate with platinum nanoparticle was successfully electrospun into a polystyrene polymer where the diameter ranged from 10 to 22 μm. The conjugates within the fiber still showed activity towards S. aureus.
- Full Text:
- Date Issued: 2014
- Authors: Managa, Muthumuni , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193791 , vital:45396 , xlink:href="https://doi.org/10.1016/j.poly.2014.03.050"
- Description: The conjugation of Pt nanoparticles with ClGa(III) 5,10,15,20-tetrakis-(4-carboxyphenyl) porphyrin (ClGaTCPP) showed greater antimicrobial activity against a gram positive and drug resistant bacteria Staphylococcus aureus, than when the porphyrin was used alone. ClGaTCPP and its conjugate with platinum nanoparticle was successfully electrospun into a polystyrene polymer where the diameter ranged from 10 to 22 μm. The conjugates within the fiber still showed activity towards S. aureus.
- Full Text:
- Date Issued: 2014
Conjugation of mono-substituted phthalocyanine derivatives to CdSe@ ZnS quantum dots and their applications as fluorescent-based sensors
- Adegoke, Oluwasesan, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189842 , vital:44936 , xlink:href="https://doi.org/10.1016/j.synthmet.2013.11.016"
- Description: Unsymmetrically substituted derivatives of aluminium amino phthalocyanines were synthesized for the first time, fully characterized and conjugated to CdSe@ZnS quantum dots (QDs). The conjugates were employed as fluorescence-based sensors for anion sensing. Among the anions that enhanced the fluorescence of the probe, fluoride ion was chosen as the test ion to test the efficacy of the probe. Förster resonance energy transfer from the QDs to the phthalocyanine was observed as an indication for the fluorescence quenching of the QDs upon binding to the phthalocyanine. The fluorescence of the linked QDs was progressively enhanced, and linearly proportional to increasing concentrations of fluoride ion. The type of substituent attached to the phthalocyanine ring influenced the efficiency of fluorescence enhancement. The proposed nanoprobe has been employed to detect fluoride ion in cell culture medium and tap water.
- Full Text:
- Date Issued: 2014
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189842 , vital:44936 , xlink:href="https://doi.org/10.1016/j.synthmet.2013.11.016"
- Description: Unsymmetrically substituted derivatives of aluminium amino phthalocyanines were synthesized for the first time, fully characterized and conjugated to CdSe@ZnS quantum dots (QDs). The conjugates were employed as fluorescence-based sensors for anion sensing. Among the anions that enhanced the fluorescence of the probe, fluoride ion was chosen as the test ion to test the efficacy of the probe. Förster resonance energy transfer from the QDs to the phthalocyanine was observed as an indication for the fluorescence quenching of the QDs upon binding to the phthalocyanine. The fluorescence of the linked QDs was progressively enhanced, and linearly proportional to increasing concentrations of fluoride ion. The type of substituent attached to the phthalocyanine ring influenced the efficiency of fluorescence enhancement. The proposed nanoprobe has been employed to detect fluoride ion in cell culture medium and tap water.
- Full Text:
- Date Issued: 2014
Conscientious objection to performing same-sex marriage in South Africa
- Authors: Kruuse, Helen
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/129186 , vital:36228 , https://doi.org/10.1093/lawfam/ebu001
- Description: This article considers whether public servants should be exempt from South Africa’s equality provisions and anti-discrimination legislation in solemnizing same-sex marriages. In order to deal with this question, the article analyses the treatment of freedom of conscience and conscientious objection by comparing the solemnization of same-sex marriage by public servants, with another public service: that of terminations of pregnancy. While each situation will inevitably turn on the particular circumstances of the case, I argue that there should be a content-neutral guiding principle (as well as consistency) in dealing with these situations. The issue in each situation is narrowed to whether a civil servant’s personal convictions can override the state’s secular obligations in providing a service, and whether there is room for a qualified right to conscientious objection. By analysing the matter in this way, it is clear that the unqualified statutory exemption clause in South Africa’s Civil Union Act is constitutionally objectionable.
- Full Text: false
- Date Issued: 2014
- Authors: Kruuse, Helen
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/129186 , vital:36228 , https://doi.org/10.1093/lawfam/ebu001
- Description: This article considers whether public servants should be exempt from South Africa’s equality provisions and anti-discrimination legislation in solemnizing same-sex marriages. In order to deal with this question, the article analyses the treatment of freedom of conscience and conscientious objection by comparing the solemnization of same-sex marriage by public servants, with another public service: that of terminations of pregnancy. While each situation will inevitably turn on the particular circumstances of the case, I argue that there should be a content-neutral guiding principle (as well as consistency) in dealing with these situations. The issue in each situation is narrowed to whether a civil servant’s personal convictions can override the state’s secular obligations in providing a service, and whether there is room for a qualified right to conscientious objection. By analysing the matter in this way, it is clear that the unqualified statutory exemption clause in South Africa’s Civil Union Act is constitutionally objectionable.
- Full Text: false
- Date Issued: 2014
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
Contextualising Curriculum Design and Recontextualising Its Implementation: The Case of Climate Change Education for Southern African Transfrontier Conservation Area Practitioners
- Mukute, Mutizwa, Pesanayi, Tichaona V
- Authors: Mukute, Mutizwa , Pesanayi, Tichaona V
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387173 , vital:68212 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/121965"
- Description: This paper discusses how the climate change education needs of park managers, ecologists, and community development officers in Southern African Development Community (SADC) Transfrontier Conservation Areas (TFCAs) were established through contextual profiling. It subsequently analyses how a curriculum that was designed in response to a contextual profiling process was recontextualised during implementation by the SADC Regional Environmental Education Programme (REEP), with support from German Federal Enterprise for International Cooperation (GIZ). The paper’s purpose is to trace the trajectory of contextualised curriculum development and implementation with a view to identifying how the twin concepts of contextual profiling and recontextualisation were utilised and lessons were learnt. The paper has potential value for educators/trainers interested in increasing the relevance of protected area workplace learning and its congruence to learners’ realities.
- Full Text:
- Date Issued: 2014
- Authors: Mukute, Mutizwa , Pesanayi, Tichaona V
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387173 , vital:68212 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/121965"
- Description: This paper discusses how the climate change education needs of park managers, ecologists, and community development officers in Southern African Development Community (SADC) Transfrontier Conservation Areas (TFCAs) were established through contextual profiling. It subsequently analyses how a curriculum that was designed in response to a contextual profiling process was recontextualised during implementation by the SADC Regional Environmental Education Programme (REEP), with support from German Federal Enterprise for International Cooperation (GIZ). The paper’s purpose is to trace the trajectory of contextualised curriculum development and implementation with a view to identifying how the twin concepts of contextual profiling and recontextualisation were utilised and lessons were learnt. The paper has potential value for educators/trainers interested in increasing the relevance of protected area workplace learning and its congruence to learners’ realities.
- Full Text:
- Date Issued: 2014
Contrasting architecture of key African and Australian savanna tree taxa drives intercontinental structural divergence
- Moncrieff, Glenn R, Lehmann, Caroline E, Schnitzler, Jan, Gambiza, James, Hiernaux, Pierre, Ryan, Casey M, Shackleton, Charlie M, Williams, Richard J, Higgins, Steven I
- Authors: Moncrieff, Glenn R , Lehmann, Caroline E , Schnitzler, Jan , Gambiza, James , Hiernaux, Pierre , Ryan, Casey M , Shackleton, Charlie M , Williams, Richard J , Higgins, Steven I
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180919 , vital:43670 , xlink:href="https://doi.org/10.1111/geb.12205"
- Description: We examined differences in the architecture of African and Australian savanna trees. We sought to attribute variation in tree architecture to current environments, wood density and phylogeny, and thereby elucidate the relative importance of biogeographic idiosyncrasies versus current factors in underpinning architectural differences.
- Full Text:
- Date Issued: 2014
- Authors: Moncrieff, Glenn R , Lehmann, Caroline E , Schnitzler, Jan , Gambiza, James , Hiernaux, Pierre , Ryan, Casey M , Shackleton, Charlie M , Williams, Richard J , Higgins, Steven I
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180919 , vital:43670 , xlink:href="https://doi.org/10.1111/geb.12205"
- Description: We examined differences in the architecture of African and Australian savanna trees. We sought to attribute variation in tree architecture to current environments, wood density and phylogeny, and thereby elucidate the relative importance of biogeographic idiosyncrasies versus current factors in underpinning architectural differences.
- Full Text:
- Date Issued: 2014
Cosmological efficacy and the politics of Sacred Place: Soli Rainmaking in contemporary Zambia
- Authors: Simbao, Ruth K
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147482 , vital:38642 , https://doi.org/10.1162/AFAR_a_00163
- Description: In this article I analyze cosmological efficacy in light of the politicization and apparent secularization of contemporary annual ceremonies in Zambia, south-central Africa, which are framed by scholars as neotraditional (Lentz 2001), folklorized (van Binsbergen 1994), or retraditionalized (Gould 2005:3, 6) events. My term “festivalization” registers the formalization of Zambian performances such as rituals, harvest festivals, inaugurations, and initiations as annual festival events, but does not imply a pejorative attitude towards cultural change and so-called inauthenticity, as the words “folklorization” or “retraditionalization” seem to do.
- Full Text:
- Date Issued: 2014
- Authors: Simbao, Ruth K
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/147482 , vital:38642 , https://doi.org/10.1162/AFAR_a_00163
- Description: In this article I analyze cosmological efficacy in light of the politicization and apparent secularization of contemporary annual ceremonies in Zambia, south-central Africa, which are framed by scholars as neotraditional (Lentz 2001), folklorized (van Binsbergen 1994), or retraditionalized (Gould 2005:3, 6) events. My term “festivalization” registers the formalization of Zambian performances such as rituals, harvest festivals, inaugurations, and initiations as annual festival events, but does not imply a pejorative attitude towards cultural change and so-called inauthenticity, as the words “folklorization” or “retraditionalization” seem to do.
- Full Text:
- Date Issued: 2014
Critical realist versus mainstream interdisciplinarity
- Authors: Price, Leigh
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391143 , vital:68624 , xlink:href="https://doi.org/10.1179/1476743013Z.00000000019"
- Description: In this paper I argue for the superiority of a critical realist understanding of interdisciplinarity over a mainstream understanding of it. I begin by exploring the reasons for the failure of mainstream researchers to achieve interdisciplinarity. My main argument is that mainstream interdisciplinary researchers tend to hypostatize facts, fetishize constant conjunctions of events and apply to open systems an epistemology designed for closed systems. I also explain how mainstream interdisciplinarity supports oppression and gross inequality. I argue that mainstream interdisciplinarity is not true interdisciplinarity and refer to it accordingly as ‘condisciplinarity’. By way of example, I examine the condisciplinarity of the World Health Organization’s ecological model applied to the issue of men’s violence against women. Specifically, I argue that critical realist interdisciplinarity is preferable because it acknowledges inter alia the empirical, actual and real layers of reality, which allows it to develop depth-explanations of phenomena. In practice, this means that critical realist interdisciplinarity can potentially provide explanations that, compared to condisciplinarity, are broader (include more of the human and non-human context) and deeper (include for example individuals’ conscious and unconscious psychological motivations). In the World Health Organization’s example of the causes of men’s violence against women, condisciplinarity resulted in the absence of historical, global and unconscious aspects of the problem. It is also restricted the analysis to reductive, constant-conjunction based theories of the causes of the problem, specifically ‘risk factors’, thereby providing a relatively shallow explanation for the problem.
- Full Text:
- Date Issued: 2014
- Authors: Price, Leigh
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391143 , vital:68624 , xlink:href="https://doi.org/10.1179/1476743013Z.00000000019"
- Description: In this paper I argue for the superiority of a critical realist understanding of interdisciplinarity over a mainstream understanding of it. I begin by exploring the reasons for the failure of mainstream researchers to achieve interdisciplinarity. My main argument is that mainstream interdisciplinary researchers tend to hypostatize facts, fetishize constant conjunctions of events and apply to open systems an epistemology designed for closed systems. I also explain how mainstream interdisciplinarity supports oppression and gross inequality. I argue that mainstream interdisciplinarity is not true interdisciplinarity and refer to it accordingly as ‘condisciplinarity’. By way of example, I examine the condisciplinarity of the World Health Organization’s ecological model applied to the issue of men’s violence against women. Specifically, I argue that critical realist interdisciplinarity is preferable because it acknowledges inter alia the empirical, actual and real layers of reality, which allows it to develop depth-explanations of phenomena. In practice, this means that critical realist interdisciplinarity can potentially provide explanations that, compared to condisciplinarity, are broader (include more of the human and non-human context) and deeper (include for example individuals’ conscious and unconscious psychological motivations). In the World Health Organization’s example of the causes of men’s violence against women, condisciplinarity resulted in the absence of historical, global and unconscious aspects of the problem. It is also restricted the analysis to reductive, constant-conjunction based theories of the causes of the problem, specifically ‘risk factors’, thereby providing a relatively shallow explanation for the problem.
- Full Text:
- Date Issued: 2014
Critical spaces: processes of othering in British Institutions of Higher Education
- Authors: Phiri, Aretha
- Date: 2014
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60741 , vital:27824 , http://www.jfsonline.org/issue7-8/articles/phiri/
- Description: Global recession and the economic crisis have affected contemporary British society in predictable ways. But this age of austerity has also unveiled the continued sinister machinations of whiteness. While not necessarily homogeneous, austerity rhetoric, as it is currently conventionally deployed, works to perpetuate white masculinist privilege and further entrenches the normative value of whiteness, while simultaneously masking and marginalizing those ethnic minority populations traditionally othered from mainstream sociopolitical discourse. More specifically, recent austerity measures adversely affect the situation of women and the future of feminist theory and practice in British higher education. This paper investigates and problematizes the deployment of austerity discourse within higher learning for its perpetuation of the normativity and hegemony of a masculinist whiteness, which further disadvantages (white) women and disrupts the practice of feminism(s) in academia.
- Full Text:
- Date Issued: 2014
- Authors: Phiri, Aretha
- Date: 2014
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/60741 , vital:27824 , http://www.jfsonline.org/issue7-8/articles/phiri/
- Description: Global recession and the economic crisis have affected contemporary British society in predictable ways. But this age of austerity has also unveiled the continued sinister machinations of whiteness. While not necessarily homogeneous, austerity rhetoric, as it is currently conventionally deployed, works to perpetuate white masculinist privilege and further entrenches the normative value of whiteness, while simultaneously masking and marginalizing those ethnic minority populations traditionally othered from mainstream sociopolitical discourse. More specifically, recent austerity measures adversely affect the situation of women and the future of feminist theory and practice in British higher education. This paper investigates and problematizes the deployment of austerity discourse within higher learning for its perpetuation of the normativity and hegemony of a masculinist whiteness, which further disadvantages (white) women and disrupts the practice of feminism(s) in academia.
- Full Text:
- Date Issued: 2014
Cytotoxicity, phytochemical analysis and antioxidant activity of crude extracts from Rhizomes of Elephantorrhiza Elephantina and Pentanisia Prunelloides
- Mpofu, Smart J, Msagati, Titus A M, Krause, Rui W M
- Authors: Mpofu, Smart J , Msagati, Titus A M , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125097 , vital:35728 , https://doi.org/10.4314/ajtcam.v11i1.6
- Description: Background: Elephantorrhiza elephantina (Ee) and Pentanisia prunelloides (Pp) are two medicinal plants which are widely used to remedy various ailments including diarrhoea, dysentery, inflammation, fever, rheumatism, heartburn, tuberculosis, haemorrhoids, skin diseases, perforated peptic ulcers and sore joints in southern Africa (South Africa, Swaziland, Botswana and Zimbabwe). The following study was conducted to explore the in vitro cytotoxicity, antioxidant properties and phytochemical profile of the two medicinal plants. Materials and Methods: The cytotoxicity of the aqueous and methanol extracts and fractions of both species was studied using the brine shrimp lethality tests (BST) for the first time. Results: The results demonstrated that the lethality (LC50) for crude extracts for both plants ranged between 1.8 and 5.8 ppm and was relatively greater than that for the methanol, ethyl acetate and chloroform fractions of the extracts which ranged between 2.1 ppm and 27 ppm. This suggested that crude extracts were more potent than their respective fractions, further explaining that the different fractions of phytochemicals in these plant species work jointly (in synergy) to exert their therapeutic efficacy. Both aqueous and methanol extracts of the two medicinal plants demonstrated a high degree of antioxidant capacity against the DPPH radical with the Duh and Yen inhibition percentage ranging between 4.5% and 72%. Phytochemical studies of the rhizome extracts showed that the major compounds present include flavonoids, tannins, anthocyanidins, anthraquinones, triterpenoids (oleanolic acid), the steroidal saponin Diosgenin, the sugars, rhamnose, glucuronic acid, Arabinose and hexoses. Conclusion: This is the first report of the detection and isolation of diosgenin and oleanolic acid from the rhizome extracts of Ee and Pp. All structures were determined using spectroscopic/spectrometric techniques (1H NMR and 13C and LC-ESI-MS) and by comparison with literature data.
- Full Text:
- Date Issued: 2014
- Authors: Mpofu, Smart J , Msagati, Titus A M , Krause, Rui W M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/125097 , vital:35728 , https://doi.org/10.4314/ajtcam.v11i1.6
- Description: Background: Elephantorrhiza elephantina (Ee) and Pentanisia prunelloides (Pp) are two medicinal plants which are widely used to remedy various ailments including diarrhoea, dysentery, inflammation, fever, rheumatism, heartburn, tuberculosis, haemorrhoids, skin diseases, perforated peptic ulcers and sore joints in southern Africa (South Africa, Swaziland, Botswana and Zimbabwe). The following study was conducted to explore the in vitro cytotoxicity, antioxidant properties and phytochemical profile of the two medicinal plants. Materials and Methods: The cytotoxicity of the aqueous and methanol extracts and fractions of both species was studied using the brine shrimp lethality tests (BST) for the first time. Results: The results demonstrated that the lethality (LC50) for crude extracts for both plants ranged between 1.8 and 5.8 ppm and was relatively greater than that for the methanol, ethyl acetate and chloroform fractions of the extracts which ranged between 2.1 ppm and 27 ppm. This suggested that crude extracts were more potent than their respective fractions, further explaining that the different fractions of phytochemicals in these plant species work jointly (in synergy) to exert their therapeutic efficacy. Both aqueous and methanol extracts of the two medicinal plants demonstrated a high degree of antioxidant capacity against the DPPH radical with the Duh and Yen inhibition percentage ranging between 4.5% and 72%. Phytochemical studies of the rhizome extracts showed that the major compounds present include flavonoids, tannins, anthocyanidins, anthraquinones, triterpenoids (oleanolic acid), the steroidal saponin Diosgenin, the sugars, rhamnose, glucuronic acid, Arabinose and hexoses. Conclusion: This is the first report of the detection and isolation of diosgenin and oleanolic acid from the rhizome extracts of Ee and Pp. All structures were determined using spectroscopic/spectrometric techniques (1H NMR and 13C and LC-ESI-MS) and by comparison with literature data.
- Full Text:
- Date Issued: 2014
Dependence on environmental resources and implications for household welfare: evidence from the Kalahari drylands, South Africa
- Thondhlana, Gladman, Muchapondwa, Edwin
- Authors: Thondhlana, Gladman , Muchapondwa, Edwin
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67810 , vital:29149 , https://doi.org/10.1016/j.ecolecon.2014.10.003
- Description: Publisher version , This paper examines dependence on environmental resources and impacts on household welfare among the indigenous San and Mier rural communities neighbouring Kgalagadi Transfrontier Park in South Africa. Data on the various household income types, including environmental income, were collected through a structured survey of 200 households. Environmental income constituted 20% of the total income. The poorest income quintile showed the highest relative dependence on environmental income (31%), though absolute environmental income increased with total income. Poverty analyses showed that poverty incidence and poverty gap would increase by 13 and 7 percentage points respectively without environmental income. Gini-coefficient analyses revealed that income inequality would increase by 6 percentage points for all households if environmental income was excluded. The results generally suggest that environmental income is important for both the poor and the well-off, and wealth accumulation might be tied to resource use. There is a case for promoting sound environmental management, and sustainable and fair resource use in the Kalahari drylands in order to help pull more households out of poverty. Our findings also point to issues of heterogeneity in resource access even among indigenous communities previously thought to be homogenous. These should be key considerations for conservation interventions.
- Full Text: false
- Date Issued: 2014
- Authors: Thondhlana, Gladman , Muchapondwa, Edwin
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67810 , vital:29149 , https://doi.org/10.1016/j.ecolecon.2014.10.003
- Description: Publisher version , This paper examines dependence on environmental resources and impacts on household welfare among the indigenous San and Mier rural communities neighbouring Kgalagadi Transfrontier Park in South Africa. Data on the various household income types, including environmental income, were collected through a structured survey of 200 households. Environmental income constituted 20% of the total income. The poorest income quintile showed the highest relative dependence on environmental income (31%), though absolute environmental income increased with total income. Poverty analyses showed that poverty incidence and poverty gap would increase by 13 and 7 percentage points respectively without environmental income. Gini-coefficient analyses revealed that income inequality would increase by 6 percentage points for all households if environmental income was excluded. The results generally suggest that environmental income is important for both the poor and the well-off, and wealth accumulation might be tied to resource use. There is a case for promoting sound environmental management, and sustainable and fair resource use in the Kalahari drylands in order to help pull more households out of poverty. Our findings also point to issues of heterogeneity in resource access even among indigenous communities previously thought to be homogenous. These should be key considerations for conservation interventions.
- Full Text: false
- Date Issued: 2014
Design of a Network Packet Processing platform
- Pennefather, Sean, Irwin, Barry V W
- Authors: Pennefather, Sean , Irwin, Barry V W
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427901 , vital:72472 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622772_Design_of_a_Network_Packet_Processing_platform/links/5b9a187f92851c4ba8181bd6/Design-of-a-Network-Packet-Processing-platform.pdf
- Description: This paper describes the design considerations investigated in the implementation of a prototype embedded network packet processing platform. The purpose of this system is to provide a means for researchers to process, and manipulate network traffic using an embedded standalone hardware platform, with the provision this be soft-configurable and flexible in its functionality. The performance of the Ethernet layer subsystem implemented using XMOS MCU’s is investigated. Future applications of this prototype are discussed.
- Full Text:
- Date Issued: 2014
- Authors: Pennefather, Sean , Irwin, Barry V W
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427901 , vital:72472 , https://www.researchgate.net/profile/Barry-Ir-win/publication/327622772_Design_of_a_Network_Packet_Processing_platform/links/5b9a187f92851c4ba8181bd6/Design-of-a-Network-Packet-Processing-platform.pdf
- Description: This paper describes the design considerations investigated in the implementation of a prototype embedded network packet processing platform. The purpose of this system is to provide a means for researchers to process, and manipulate network traffic using an embedded standalone hardware platform, with the provision this be soft-configurable and flexible in its functionality. The performance of the Ethernet layer subsystem implemented using XMOS MCU’s is investigated. Future applications of this prototype are discussed.
- Full Text:
- Date Issued: 2014
Development and evaluation of pictograms on medication labels for patients with limited literacy skills in a culturally diverse multiethnic population:
- Kheir, Nadir, Awaisu, Ahmed, Radoui, Amina, El Badawi, Aya, Jean, Linda, Dowse, Roslind
- Authors: Kheir, Nadir , Awaisu, Ahmed , Radoui, Amina , El Badawi, Aya , Jean, Linda , Dowse, Roslind
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156720 , vital:40041 , https://doi.org/10.1016/j.sapharm.2013.11.003
- Description: Much of the migrant workforce in Qatar is of low literacy level and does not understand Arabic or English, presenting a significant challenge to health care professionals. Medicine labels are typically in Arabic and English and are therefore poorly understood by these migrant workers. To develop pictograms illustrating selected medicine label instructions and to evaluate comprehension of the pictograms or conventional text supported with verbal instructions in foreign workers with low literacy skills.
- Full Text:
- Date Issued: 2014
- Authors: Kheir, Nadir , Awaisu, Ahmed , Radoui, Amina , El Badawi, Aya , Jean, Linda , Dowse, Roslind
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156720 , vital:40041 , https://doi.org/10.1016/j.sapharm.2013.11.003
- Description: Much of the migrant workforce in Qatar is of low literacy level and does not understand Arabic or English, presenting a significant challenge to health care professionals. Medicine labels are typically in Arabic and English and are therefore poorly understood by these migrant workers. To develop pictograms illustrating selected medicine label instructions and to evaluate comprehension of the pictograms or conventional text supported with verbal instructions in foreign workers with low literacy skills.
- Full Text:
- Date Issued: 2014
Development of Graphene/CdSe Quantum Dots‐Co Phthalocyanine Nanocomposite for Oxygen Reduction Reaction
- Nyoni, Stephen, Nyokong, Tebello
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189944 , vital:44950 , xlink:href="https://doi.org/10.1002/elan.201400372"
- Description: Nanocomposites containing CdSe quantum dots, tetra(4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II)) (CoPyPc) and reduced graphene nanosheets (rGNS) were devoloped and used for the modification of a glassy carbon electrode. Characterization of the nanocomposites was done by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses. Cyclic voltammetry (CV) was used for electrochemical characterization of the prepared nanocomposite for oxygen reduction reaction. The oxygen reduction activity for rGNS/CdSe-CoPyPc nanocomposite was found to be superior over the individual nanomaterials in this study. The activity of the nanocomposite towards oxygen reduction was also tested for tolerance to methanol crossover effect using chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) studies.
- Full Text:
- Date Issued: 2014
- Authors: Nyoni, Stephen , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189944 , vital:44950 , xlink:href="https://doi.org/10.1002/elan.201400372"
- Description: Nanocomposites containing CdSe quantum dots, tetra(4-(4,6-diaminopyrimidin-2-ylthio) phthalocyaninatocobalt(II)) (CoPyPc) and reduced graphene nanosheets (rGNS) were devoloped and used for the modification of a glassy carbon electrode. Characterization of the nanocomposites was done by transmission electron microscopy (TEM) and X-ray diffraction (XRD) analyses. Cyclic voltammetry (CV) was used for electrochemical characterization of the prepared nanocomposite for oxygen reduction reaction. The oxygen reduction activity for rGNS/CdSe-CoPyPc nanocomposite was found to be superior over the individual nanomaterials in this study. The activity of the nanocomposite towards oxygen reduction was also tested for tolerance to methanol crossover effect using chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) studies.
- Full Text:
- Date Issued: 2014
Diagnosing the sexual pattern of Diplodus cervinus hottentotus (Pisces: Sparidae) from southern Angola
- Winkler, Alexander C, Santos, Carmen V D, Potts, Warren M
- Authors: Winkler, Alexander C , Santos, Carmen V D , Potts, Warren M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124286 , vital:35589 , https://doi.10.1007/s11160-006-9034-6
- Description: The sexual pattern of Diplodus cervinus hottentotus was investigated in southern Angola. Females were significantly smaller and found in greater numbers, with an adult sex ratio of 1.0:0.7, F:M. Histological observations of preserved gonads indicated that the species is a rudimentary hermaphrodite, possessing a non-functional bisexual ovotestis before maturation. Histological examination of five macroscopically staged ‘bisexual’ individuals revealed that they were functional males with residual ovarian tissue in the gonad, which had persisted from a juvenile bisexual stage. Although empirical population structure and macroscopic observations suggested protogyny, histological evidence suggested otherwise, confirming the need for the use of histology when diagnosing the sexual pattern of sparid fishes.
- Full Text:
- Date Issued: 2014
- Authors: Winkler, Alexander C , Santos, Carmen V D , Potts, Warren M
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124286 , vital:35589 , https://doi.10.1007/s11160-006-9034-6
- Description: The sexual pattern of Diplodus cervinus hottentotus was investigated in southern Angola. Females were significantly smaller and found in greater numbers, with an adult sex ratio of 1.0:0.7, F:M. Histological observations of preserved gonads indicated that the species is a rudimentary hermaphrodite, possessing a non-functional bisexual ovotestis before maturation. Histological examination of five macroscopically staged ‘bisexual’ individuals revealed that they were functional males with residual ovarian tissue in the gonad, which had persisted from a juvenile bisexual stage. Although empirical population structure and macroscopic observations suggested protogyny, histological evidence suggested otherwise, confirming the need for the use of histology when diagnosing the sexual pattern of sparid fishes.
- Full Text:
- Date Issued: 2014