Photophysicochemical behavior and antimicrobial activity of dihydroxosilicon tris (diaquaplatinum) octacarboxyphthalocyanine
- Managa, Muthumuni, Idowu, Mopelola A I, Antunes, Edith M, Nyokong, Tebello
- Authors: Managa, Muthumuni , Idowu, Mopelola A I , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241527 , vital:50947 , xlink:href="https://doi.org/10.1016/j.saa.2014.01.087"
- Description: Platination of dihydroxosilicon octacarboxyphthalocyanine (OH)2SiOCPc was successfully carried out to give dihydroxosilicon tris(diaquaplatinum)octacarboxyphthalocyanine (OH)2SiOCPc(Pt)3 conjugate. Slight blue shifting of the absorption spectrum of (OH)2SiOCPc(Pt)3 was observed on conjugation with platinum. Comparative photophysicochemical behavior and antimicrobial photo-activities of (OH)2SiOCPc(Pt)3 conjugate with (OH)2SiOCPc or Pt nanoparticles revealed that the heavy atom, Pt on the periphery of the phthalocyanine significantly enhanced its singlet oxygen generation with a quantum yield of 0.56 obtained for the (OH)2SiOCPc(Pt)3 conjugate. The (OH)2SiOCPc(Pt)3 conjugate showed highest antimicrobial activity towards Candida albicans and Escherichia coli compared to (OH)2SiOCPc and Pt nanoparticles alone under illumination.
- Full Text:
- Authors: Managa, Muthumuni , Idowu, Mopelola A I , Antunes, Edith M , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241527 , vital:50947 , xlink:href="https://doi.org/10.1016/j.saa.2014.01.087"
- Description: Platination of dihydroxosilicon octacarboxyphthalocyanine (OH)2SiOCPc was successfully carried out to give dihydroxosilicon tris(diaquaplatinum)octacarboxyphthalocyanine (OH)2SiOCPc(Pt)3 conjugate. Slight blue shifting of the absorption spectrum of (OH)2SiOCPc(Pt)3 was observed on conjugation with platinum. Comparative photophysicochemical behavior and antimicrobial photo-activities of (OH)2SiOCPc(Pt)3 conjugate with (OH)2SiOCPc or Pt nanoparticles revealed that the heavy atom, Pt on the periphery of the phthalocyanine significantly enhanced its singlet oxygen generation with a quantum yield of 0.56 obtained for the (OH)2SiOCPc(Pt)3 conjugate. The (OH)2SiOCPc(Pt)3 conjugate showed highest antimicrobial activity towards Candida albicans and Escherichia coli compared to (OH)2SiOCPc and Pt nanoparticles alone under illumination.
- Full Text:
Photophysicochemical properties and TD-DFT calculations of a novel terminal alkyne substituted metal free phthalocyanine
- Yilmaz, Yusuf, Mack, John, Sönmez, Mehmet, Nyokong, Tebello
- Authors: Yilmaz, Yusuf , Mack, John , Sönmez, Mehmet , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241562 , vital:50950 , xlink:href="https://doi.org/10.1142/S1088424613501241"
- Description: The synthesis of a novel free base tetrakis(prop-2-ynyloxy)phthalocyanine (2) is described, along with its characterization by IR, UV-visible absorption, and 1H NMR spectroscopy and mass spectrometry. The compound exhibited good solubility in a wide range of organic solvents and no significant aggregation was observed over a wide concentration range. The values for the singlet oxygen (ΦΔ), photodegradation, fluorescence (ΦF) and triplet state quantum yields and the fluorescence and triplet state lifetimes are reported. A relatively high ΦΔ value of 0.46 was obtained in DMSO. The ability to carry out "click" chemistry at the ligand periphery enhances the potential utility of 2 for use in bioconjugates in photodynamic therapy (PDT). A moderately high ΦF value of 0.18 is observed for emission in the therapeutic window in the near-IR region, which suggests that it may also be possible to determine the level of localization of 2 in tumor cells through bioimaging.
- Full Text:
- Authors: Yilmaz, Yusuf , Mack, John , Sönmez, Mehmet , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241562 , vital:50950 , xlink:href="https://doi.org/10.1142/S1088424613501241"
- Description: The synthesis of a novel free base tetrakis(prop-2-ynyloxy)phthalocyanine (2) is described, along with its characterization by IR, UV-visible absorption, and 1H NMR spectroscopy and mass spectrometry. The compound exhibited good solubility in a wide range of organic solvents and no significant aggregation was observed over a wide concentration range. The values for the singlet oxygen (ΦΔ), photodegradation, fluorescence (ΦF) and triplet state quantum yields and the fluorescence and triplet state lifetimes are reported. A relatively high ΦΔ value of 0.46 was obtained in DMSO. The ability to carry out "click" chemistry at the ligand periphery enhances the potential utility of 2 for use in bioconjugates in photodynamic therapy (PDT). A moderately high ΦF value of 0.18 is observed for emission in the therapeutic window in the near-IR region, which suggests that it may also be possible to determine the level of localization of 2 in tumor cells through bioimaging.
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Phylogeny of the family Trogidae (Coleoptera: Scarabaeoidea) inferred from mitochondrial and nuclear ribosomal DNA sequence data
- Strümpher, Werner P, Sole, Catherine L, Villet, Martin H, Scholtz, Clarke H
- Authors: Strümpher, Werner P , Sole, Catherine L , Villet, Martin H , Scholtz, Clarke H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442253 , vital:73970 , https://doi.org/10.1111/syen.12074
- Description: Trogidae constitute a monophyletic and biologically unique family within Scarabaeoidea, being the only keratinophagous group in the superfamily. Traditionally, the family has been divided into three distinctive genera, Polynoncus Burmeister, Omorgus Erichson and Trox Fabricius. Although the taxonomy of the group is relatively well studied, changes to the existing classification have recently been proposed and the family as currently constituted has not been subjected to phylogenetic analyses. Here we present a molecular phylogeny for this cosmopolitan family based on three partially sequenced gene regions: 16S rRNA, 18S rRNA and 28S rRNA (domain 2). Included in the analyses are representatives belonging to four of the five extant genera (and three of the four subgenera) from all major zoogeographic regions, representing about 20% of the known trogid species diversity in the family. Phylogenetic analyses performed included parsimony and Bayesian inference. We deduce their historical biogeography by using trogid fossils as calibration points for divergence estimates. Our analyses resolved relationships between and within genera and subgenera that are largely congruent with existing phylogeny hypotheses based on morphological data. We recovered four well‐supported radiations: Polynoncus, Omorgus, Holarctic Trox and African Phoberus MacLeay. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. The subgenera Trox and Phoberus should be elevated to genera to include the Holarctic and all the Afrotropical species, respectively, and Afromorgus returned to subgeneric rank. Estimates of divergence time are consistent with a Pangaean origin of the family in the Early Jurassic. The subsequent diversification of the major lineages is largely attributed to the break‐up of Pangaea and Gondwana in the Middle Jurassic and early Late Cretaceous, respectively.
- Full Text:
- Authors: Strümpher, Werner P , Sole, Catherine L , Villet, Martin H , Scholtz, Clarke H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442253 , vital:73970 , https://doi.org/10.1111/syen.12074
- Description: Trogidae constitute a monophyletic and biologically unique family within Scarabaeoidea, being the only keratinophagous group in the superfamily. Traditionally, the family has been divided into three distinctive genera, Polynoncus Burmeister, Omorgus Erichson and Trox Fabricius. Although the taxonomy of the group is relatively well studied, changes to the existing classification have recently been proposed and the family as currently constituted has not been subjected to phylogenetic analyses. Here we present a molecular phylogeny for this cosmopolitan family based on three partially sequenced gene regions: 16S rRNA, 18S rRNA and 28S rRNA (domain 2). Included in the analyses are representatives belonging to four of the five extant genera (and three of the four subgenera) from all major zoogeographic regions, representing about 20% of the known trogid species diversity in the family. Phylogenetic analyses performed included parsimony and Bayesian inference. We deduce their historical biogeography by using trogid fossils as calibration points for divergence estimates. Our analyses resolved relationships between and within genera and subgenera that are largely congruent with existing phylogeny hypotheses based on morphological data. We recovered four well‐supported radiations: Polynoncus, Omorgus, Holarctic Trox and African Phoberus MacLeay. On the basis of this study, it is proposed that taxonomic changes to the generic classification of the family be made. The subgenera Trox and Phoberus should be elevated to genera to include the Holarctic and all the Afrotropical species, respectively, and Afromorgus returned to subgeneric rank. Estimates of divergence time are consistent with a Pangaean origin of the family in the Early Jurassic. The subsequent diversification of the major lineages is largely attributed to the break‐up of Pangaea and Gondwana in the Middle Jurassic and early Late Cretaceous, respectively.
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Phytoplankton community diversity along a river-estuary continuum
- Dalu, Tatenda, Froneman, P William, Richoux, Nicole B
- Authors: Dalu, Tatenda , Froneman, P William , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457284 , vital:75622 , xlink:href="https://hdl.handle.net/10520/EJC156752"
- Description: In this paper we examine the aspects of phytoplankton communities along a riverine-estuarine continuum in the Kowie system, Eastern Cape (South Africa). This study aims to relate the phytoplankton population community structure to physicochemical parameters and estimate the different chlorophyll-a concentrations for the Kowie system. Eight sampling sites along a 70 km reach of the Kowie system were sampled over a one-year period. One hundred and seventy-eight species belonging to 78 genera were recorded within the riverine-estuarine continuum. Diatoms were predominant, accounting for 81.9% of the total abundance. The estuary had 98 species (55 genera) recorded whereas the river had 141 species (67 genera). Using a two-way analysis of variance (ANOVA), species richness was found to differ significantly amongst seasons. The chl-a concentration along the estuarine-riverine continuum increased from spring to a high in summer (river mean = 7.9 mg m -3 and estuary mean = 3.3 mg m -3 ) before decreasing to a low in winter. Kruskal Wallis ANOVA showed significant differences among chl-a concentration with seasons and sites. Redundancy analysis identified five factors salinity, water depth, aerial cover, nitrates and ammonia that were significant (p is less than 0.05) in affecting phytoplankton variation. The relatively small study indicates the need for further monitoring to gain a better understanding of Kowie system phytoplankton.
- Full Text:
- Authors: Dalu, Tatenda , Froneman, P William , Richoux, Nicole B
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/457284 , vital:75622 , xlink:href="https://hdl.handle.net/10520/EJC156752"
- Description: In this paper we examine the aspects of phytoplankton communities along a riverine-estuarine continuum in the Kowie system, Eastern Cape (South Africa). This study aims to relate the phytoplankton population community structure to physicochemical parameters and estimate the different chlorophyll-a concentrations for the Kowie system. Eight sampling sites along a 70 km reach of the Kowie system were sampled over a one-year period. One hundred and seventy-eight species belonging to 78 genera were recorded within the riverine-estuarine continuum. Diatoms were predominant, accounting for 81.9% of the total abundance. The estuary had 98 species (55 genera) recorded whereas the river had 141 species (67 genera). Using a two-way analysis of variance (ANOVA), species richness was found to differ significantly amongst seasons. The chl-a concentration along the estuarine-riverine continuum increased from spring to a high in summer (river mean = 7.9 mg m -3 and estuary mean = 3.3 mg m -3 ) before decreasing to a low in winter. Kruskal Wallis ANOVA showed significant differences among chl-a concentration with seasons and sites. Redundancy analysis identified five factors salinity, water depth, aerial cover, nitrates and ammonia that were significant (p is less than 0.05) in affecting phytoplankton variation. The relatively small study indicates the need for further monitoring to gain a better understanding of Kowie system phytoplankton.
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Platinum share prices and the Marikana tragedy: an event study
- Authors: Sunga, Tapuwa Terence
- Date: 2014
- Subjects: Marikana (Rustenburg, South Africa) , Massacres -- South Africa -- Rustenburg , Stocks -- Prices -- South Africa , Stocks -- Prices -- Mathematical models
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1094 , http://hdl.handle.net/10962/d1013002
- Description: An event study is an economic tool of analysis that has begun to gain popularity in recent empirical literature. It is a technique that gives a researcher the opportunity to map out the reaction of a firm's stock to an event, usually making use of daily or monthly data. However, up to this point, event study methodology has generally been applied to more traditional phenomena capable of affecting equity value, such as dividend and macroeconomic policy announcements, and there have only been a few exceptions to this. This study looks at what impact the tragic shootings at Lonmin mine in Marikana on August 16th 2012 had on the share prices of platinum mining firms based in South Africa using event study methodology. It makes use of the technique to investigate how the share prices responded to the tragedy over a number of trading days, including the day of the shootings. To be best of our knowledge, no attempt has been made to analyse the impact on share prices using events of this nature. For the investigation, daily returns data was used for each firm. The abnormal returns and cumulative abnormal returns to each were then calculated and compared with their respective expected returns in order to determine whether investors in the shares of that particular firm reacted positively, negatively or not at all. The evidence found suggests that tragedies of this nature are capable of influencing share prices in the same manner as more traditional economic phenomena. Overall, only one firm was found to have been negatively affected by the shootings in a persistent manner, while the shares of the other firms examined reacted in a manner that was positive overall, but varied according to individual firm characteristics such as size. These finding conformed to our a priori expectations. In addition, the results also confirm the benefits of applying event study methodology to a wide variety of phenomena that fall outside the boundaries usually associated with business.
- Full Text:
- Authors: Sunga, Tapuwa Terence
- Date: 2014
- Subjects: Marikana (Rustenburg, South Africa) , Massacres -- South Africa -- Rustenburg , Stocks -- Prices -- South Africa , Stocks -- Prices -- Mathematical models
- Language: English
- Type: Thesis , Masters , MCom
- Identifier: vital:1094 , http://hdl.handle.net/10962/d1013002
- Description: An event study is an economic tool of analysis that has begun to gain popularity in recent empirical literature. It is a technique that gives a researcher the opportunity to map out the reaction of a firm's stock to an event, usually making use of daily or monthly data. However, up to this point, event study methodology has generally been applied to more traditional phenomena capable of affecting equity value, such as dividend and macroeconomic policy announcements, and there have only been a few exceptions to this. This study looks at what impact the tragic shootings at Lonmin mine in Marikana on August 16th 2012 had on the share prices of platinum mining firms based in South Africa using event study methodology. It makes use of the technique to investigate how the share prices responded to the tragedy over a number of trading days, including the day of the shootings. To be best of our knowledge, no attempt has been made to analyse the impact on share prices using events of this nature. For the investigation, daily returns data was used for each firm. The abnormal returns and cumulative abnormal returns to each were then calculated and compared with their respective expected returns in order to determine whether investors in the shares of that particular firm reacted positively, negatively or not at all. The evidence found suggests that tragedies of this nature are capable of influencing share prices in the same manner as more traditional economic phenomena. Overall, only one firm was found to have been negatively affected by the shootings in a persistent manner, while the shares of the other firms examined reacted in a manner that was positive overall, but varied according to individual firm characteristics such as size. These finding conformed to our a priori expectations. In addition, the results also confirm the benefits of applying event study methodology to a wide variety of phenomena that fall outside the boundaries usually associated with business.
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Political grey : areas of ambiguity and contradiction
- Authors: Koekemoer, Carmen
- Date: 2014
- Subjects: Politics in art , Art -- Political aspects -- South Africa , Leadership in art , Portraits, African , Portraits, European , Art and revolutions -- South Africa
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2492 , http://hdl.handle.net/10962/d1013136
- Description: This Master of Fine Arts submission, consisting of a thesis titled ‘Political Grey: Areas of Ambiguity and Contradiction’ accompanied by an exhibition titled ‘Positions’, encompasses the concept of leadership while uncovering and expressing its ‘grey areas’ in a contemporary and undefined moment in South Africa. The concept of leadership has been complicated throughout the thesis in terms of how it is conceptualised in a traditional royal African art context as well as how Leader-Figures have been and are portrayed in both Western and African portrait genres. The notion that the new is built upon the old is continued throughout my thesis and is evident in the accompanying body of work. This notion is expressed on a number of levels: by the re-contextualisation of the print medium; the creative processes described as ‘postproduction’ which I use in my work; as well as that which is described as a ‘post-transitional’ moment. The recent political history of the country is considered, with reference made to the anti-apartheid movement and resistance art produced. Printmaking, viewed as an archetypal medium for resistance, is discussed, with reference made to its socio-political role during the 1980s as well as to the extent to which it continues to be used by contemporary artists in a different realm of conflict and change. This is demonstrated by the shift from the medium as a tool for protest to the medium as an instrument of political irony and pointed commentary.
- Full Text:
- Authors: Koekemoer, Carmen
- Date: 2014
- Subjects: Politics in art , Art -- Political aspects -- South Africa , Leadership in art , Portraits, African , Portraits, European , Art and revolutions -- South Africa
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2492 , http://hdl.handle.net/10962/d1013136
- Description: This Master of Fine Arts submission, consisting of a thesis titled ‘Political Grey: Areas of Ambiguity and Contradiction’ accompanied by an exhibition titled ‘Positions’, encompasses the concept of leadership while uncovering and expressing its ‘grey areas’ in a contemporary and undefined moment in South Africa. The concept of leadership has been complicated throughout the thesis in terms of how it is conceptualised in a traditional royal African art context as well as how Leader-Figures have been and are portrayed in both Western and African portrait genres. The notion that the new is built upon the old is continued throughout my thesis and is evident in the accompanying body of work. This notion is expressed on a number of levels: by the re-contextualisation of the print medium; the creative processes described as ‘postproduction’ which I use in my work; as well as that which is described as a ‘post-transitional’ moment. The recent political history of the country is considered, with reference made to the anti-apartheid movement and resistance art produced. Printmaking, viewed as an archetypal medium for resistance, is discussed, with reference made to its socio-political role during the 1980s as well as to the extent to which it continues to be used by contemporary artists in a different realm of conflict and change. This is demonstrated by the shift from the medium as a tool for protest to the medium as an instrument of political irony and pointed commentary.
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Political party institutionalization : a case study of Kenya
- Mutizwa-Mangiza, Shingai Price
- Authors: Mutizwa-Mangiza, Shingai Price
- Date: 2014
- Subjects: Kenya -- Politics and government , Political parties -- Kenya , Kenya -- History , Kenya -- Colonial influence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2881 , http://hdl.handle.net/10962/d1013258
- Description: This thesis explores the nature and extent of political party institutionalization in Kenya. More specifically, it focuses on the four dimensions of party institutionalization, namely organizational systemness, value-infusion, decisional autonomy and reification. The study itself is largely located within the historical-institutionalist school of thought, with particular emphasis on the path dependency strand of this theoretical framework. However, the study also employs a political economy approach. It recognizes that the development trajectory of party politics in Kenya did not evolve in a vacuum but within a particular historical-institutional and political-economic context. The thesis advances the notion that those current low levels of party institutionalization that are evident in almost all parties, and the relatively peripheral role that they have in Kenya's governance can be traced to Kenya's colonial and post-colonial political history, the resource poor environment and the onset of globalization.
- Full Text:
- Authors: Mutizwa-Mangiza, Shingai Price
- Date: 2014
- Subjects: Kenya -- Politics and government , Political parties -- Kenya , Kenya -- History , Kenya -- Colonial influence
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2881 , http://hdl.handle.net/10962/d1013258
- Description: This thesis explores the nature and extent of political party institutionalization in Kenya. More specifically, it focuses on the four dimensions of party institutionalization, namely organizational systemness, value-infusion, decisional autonomy and reification. The study itself is largely located within the historical-institutionalist school of thought, with particular emphasis on the path dependency strand of this theoretical framework. However, the study also employs a political economy approach. It recognizes that the development trajectory of party politics in Kenya did not evolve in a vacuum but within a particular historical-institutional and political-economic context. The thesis advances the notion that those current low levels of party institutionalization that are evident in almost all parties, and the relatively peripheral role that they have in Kenya's governance can be traced to Kenya's colonial and post-colonial political history, the resource poor environment and the onset of globalization.
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Polyamide nanofiber membranes functionalized with zinc phthalocyanines
- Goethals, Annelies, Mugadza, Tawanda, Arslanoglu, Yasin, Zugle, Ruphino, Antunes, Edith M, Van Hulle, Stijn W, Nyokong, Tebello, De Clerck, Karen
- Authors: Goethals, Annelies , Mugadza, Tawanda , Arslanoglu, Yasin , Zugle, Ruphino , Antunes, Edith M , Van Hulle, Stijn W , Nyokong, Tebello , De Clerck, Karen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241505 , vital:50945 , xlink:href="https://doi.org/10.1002/app.40486"
- Description: Electrospinning is an efficient method for the production of polyamide nanofiber membranes that are suitable for water filtration. Previous studies have shown that nanofiber membranes have high clean water permeability. The pathogen removal efficiency can be improved by functionalization with (organic) biocides. However, these membranes, like other membranes, are vulnerable to fouling which reduces the filtration efficiency. Therefore the present article investigates the potential of zinc phthalocyanines, which can produce singlet oxygen in the presence of visible light, as a functionalizing agent. The polyamide nanofiber membranes were functionalized with phthalocyanines using both a pre-functionalizing and post-functionalizing method. Only the post-functionalization method shows to result in nanofiber membranes capable of producing singlet oxygen. After 30 min 45% of 1,2-diphenylisobenzofuran (DPBF), used as an oxygen quencher, was removed by reaction with singlet oxygen. This resulted in a removal rate of 0.33 mol DBPF mol−1Zn min−1. During short term leaching tests, phthalocyanines could not be detected.
- Full Text:
- Authors: Goethals, Annelies , Mugadza, Tawanda , Arslanoglu, Yasin , Zugle, Ruphino , Antunes, Edith M , Van Hulle, Stijn W , Nyokong, Tebello , De Clerck, Karen
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241505 , vital:50945 , xlink:href="https://doi.org/10.1002/app.40486"
- Description: Electrospinning is an efficient method for the production of polyamide nanofiber membranes that are suitable for water filtration. Previous studies have shown that nanofiber membranes have high clean water permeability. The pathogen removal efficiency can be improved by functionalization with (organic) biocides. However, these membranes, like other membranes, are vulnerable to fouling which reduces the filtration efficiency. Therefore the present article investigates the potential of zinc phthalocyanines, which can produce singlet oxygen in the presence of visible light, as a functionalizing agent. The polyamide nanofiber membranes were functionalized with phthalocyanines using both a pre-functionalizing and post-functionalizing method. Only the post-functionalization method shows to result in nanofiber membranes capable of producing singlet oxygen. After 30 min 45% of 1,2-diphenylisobenzofuran (DPBF), used as an oxygen quencher, was removed by reaction with singlet oxygen. This resulted in a removal rate of 0.33 mol DBPF mol−1Zn min−1. During short term leaching tests, phthalocyanines could not be detected.
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Positioning non-timber forest products on the development agenda
- Shackleton, Charlie M, Pandey, Ashok K
- Authors: Shackleton, Charlie M , Pandey, Ashok K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180992 , vital:43679 , xlink:href="https://doi.org/10.1016/j.forpol.2013.07.004"
- Description: Non-timber forests products (NTFPs) provide multiple livelihood benefits to local communities and regional and national economies. And yet this knowledge is rarely drawn upon in debates around and design of poverty alleviation or land use policies, strategies and projects. Unless the accumulating wealth of empirical evidence can be translated into policies and approaches at higher levels, and integrated into poverty alleviation programmes, it will have little impact on local and national poverty profiles. In this paper we propose and briefly discuss eight steps to facilitate integration of NTFPs into the development agenda, for the benefit of local communities. These include: (1) proper inventory of NTFP stocks, (2) research on NTFP ecology and sustainable harvest levels, (3) introduction of extension services for NTFPs, (4) inclusion of NTFPs in land management and trade-off decisions, (5) integration of NTFPs into sectoral policies, (6) ensuring NTFP commercialisation is not at the expense of local livelihood needs, (7) promoting security of access and use, and (8) examination of local contextual drivers of unsustainable use. Each is presented along with examples or proposals towards implementation.
- Full Text:
- Authors: Shackleton, Charlie M , Pandey, Ashok K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180992 , vital:43679 , xlink:href="https://doi.org/10.1016/j.forpol.2013.07.004"
- Description: Non-timber forests products (NTFPs) provide multiple livelihood benefits to local communities and regional and national economies. And yet this knowledge is rarely drawn upon in debates around and design of poverty alleviation or land use policies, strategies and projects. Unless the accumulating wealth of empirical evidence can be translated into policies and approaches at higher levels, and integrated into poverty alleviation programmes, it will have little impact on local and national poverty profiles. In this paper we propose and briefly discuss eight steps to facilitate integration of NTFPs into the development agenda, for the benefit of local communities. These include: (1) proper inventory of NTFP stocks, (2) research on NTFP ecology and sustainable harvest levels, (3) introduction of extension services for NTFPs, (4) inclusion of NTFPs in land management and trade-off decisions, (5) integration of NTFPs into sectoral policies, (6) ensuring NTFP commercialisation is not at the expense of local livelihood needs, (7) promoting security of access and use, and (8) examination of local contextual drivers of unsustainable use. Each is presented along with examples or proposals towards implementation.
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Potential Gaps during the Transition from the Embodied through Symbolic to Formal Worlds of Reflective Symmetry:
- Mhlolo, Michael K, Schäfer, Marc
- Authors: Mhlolo, Michael K , Schäfer, Marc
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141117 , vital:37945 , https://doi.org/10.1080/10288457.2014.925269
- Description: Even though reflective symmetry is heavily embedded in the everyday, learners continue to experience challenges when they mathematize concepts from this informal/everyday context. In this article we argue that symmetry exists in nature, it can also be symbolized algebraically and it can be abstracted into the world of axioms and theorems. We problematize this multiple nature of symmetry which on one hand is supportive and on the other acts as a contributory factor to learners' gaps in knowledge. Tall's three worlds of mathematics helped us to show the transition of symmetry from the embodied through symbolic to the formal world and the inherent gaps attributed to the shifts in thinking thereof. We then used this same framework to analyse learners' responses to a reflective symmetry task. The results show that many learner responses could be explained explicitly by the lack of flexibility in the applicability of experiences in the embodied world of reflective symmetry.
- Full Text:
- Authors: Mhlolo, Michael K , Schäfer, Marc
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141117 , vital:37945 , https://doi.org/10.1080/10288457.2014.925269
- Description: Even though reflective symmetry is heavily embedded in the everyday, learners continue to experience challenges when they mathematize concepts from this informal/everyday context. In this article we argue that symmetry exists in nature, it can also be symbolized algebraically and it can be abstracted into the world of axioms and theorems. We problematize this multiple nature of symmetry which on one hand is supportive and on the other acts as a contributory factor to learners' gaps in knowledge. Tall's three worlds of mathematics helped us to show the transition of symmetry from the embodied through symbolic to the formal world and the inherent gaps attributed to the shifts in thinking thereof. We then used this same framework to analyse learners' responses to a reflective symmetry task. The results show that many learner responses could be explained explicitly by the lack of flexibility in the applicability of experiences in the embodied world of reflective symmetry.
- Full Text:
Poverty incidence among smallholder farmers in the amathole district municipality, Eastern Cape Province, South Africa
- Baiyegunhi, Lloyd J S, Fraser, Gavin C G
- Authors: Baiyegunhi, Lloyd J S , Fraser, Gavin C G
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/472681 , vital:77562 , DOI: 10.31901/24566608.2014/46.03.02
- Description: Strategies aimed at poverty alleviation need to identify factors that are strongly associated with poverty and are amenable to modification by policy. The study employed a household welfare function, approximated by household expenditure per adult equivalent to offer explanation for the incidence of poverty and its correlates. Data were collected from a household level survey of 150 smallholder farmers in the Amathole District Municipality, Eastern Cape Province of South Africa. The Foster, Greer, and Thorbecke (FGT) poverty index was used to analyse the extent and severity of poverty and the results revealed that about 44 percent of the sampled households live below poverty line with average poverty gap of 0.097, while results from the Tobit regression model showed that household head’s gender, age, education, households’ dependency ratio, occupation, security of land rights, credit availability, social capital and assets ownership are important determinants of smallholder farmers’ poverty. Implications for smallholder farmers’ poverty reduction were discussed.
- Full Text:
- Authors: Baiyegunhi, Lloyd J S , Fraser, Gavin C G
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/472681 , vital:77562 , DOI: 10.31901/24566608.2014/46.03.02
- Description: Strategies aimed at poverty alleviation need to identify factors that are strongly associated with poverty and are amenable to modification by policy. The study employed a household welfare function, approximated by household expenditure per adult equivalent to offer explanation for the incidence of poverty and its correlates. Data were collected from a household level survey of 150 smallholder farmers in the Amathole District Municipality, Eastern Cape Province of South Africa. The Foster, Greer, and Thorbecke (FGT) poverty index was used to analyse the extent and severity of poverty and the results revealed that about 44 percent of the sampled households live below poverty line with average poverty gap of 0.097, while results from the Tobit regression model showed that household head’s gender, age, education, households’ dependency ratio, occupation, security of land rights, credit availability, social capital and assets ownership are important determinants of smallholder farmers’ poverty. Implications for smallholder farmers’ poverty reduction were discussed.
- Full Text:
Predation by alien largemouth bass, Micropterus salmoides Lacepéde 1802 (Centrarchidae: Perciformes), on indigenous marine fish species in the Kowie System, South Africa
- Authors: Magoro, Mandla Leon
- Date: 2014
- Subjects: Largemouth bass -- South Africa -- Port Alfred , Largemouth bass -- Food -- South Africa -- Port Alfred , Estuarine fishes -- South Africa -- Port Alfred , Estuarine fishes -- Predators of , Centrarchidae , Fishes -- Effect of human beings on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5851 , http://hdl.handle.net/10962/d1011939 , Largemouth bass -- South Africa -- Port Alfred , Largemouth bass -- Food -- South Africa -- Port Alfred , Estuarine fishes -- South Africa -- Port Alfred , Estuarine fishes -- Predators of , Centrarchidae , Fishes -- Effect of human beings on
- Description: Estuaries serve as nursery areas for a large number of estuary-associated fish species. Some of these taxa also use river catchments as nursery areas. During the upstream migration of this latter group, the juveniles are prone to predation by native and alien predatory fish inhabiting the system. The rate of invasion of ecosystems by alien organisms can be directly linked to anthropogenic influences, including both intentional and unintentional introductions by alien organisms into new regions. The largemouth bass, Micropterus salmoides, is a facultative piscivorous fish that has been successfully introduced worldwide for the main purpose of sport fishing. Where introduced, it has been found to negatively impact native fish and invertebrate species through predation, competitive exclusion and displacement of indigenous fish species. The aim of this thesis was to investigate the predatory impact of largemouth bass on the estuary-associated Cape moony Monodactylus falciformis, Cape stumpnose Rhabdosargus holubi and freshwater mullet Myxus capensis in the lower Kowie River of the Eastern Cape Province, South Africa. A combination of approaches was employed during this study. Stomach contents, stable isotopes and fatty acid analyses were employed for the reconstruction of the diet of largemouth bass. Acoustic telemetry was used to elucidate largemouth bass movements, particularly their ability to enter the upper reaches of the Kowie Estuary. Stomach contents and stable isotopes analyses showed that M. salmoides exhibit an ontogenic shift in diet, with small and medium sized individuals consuming the higher proportion of fish prey, while large sized individuals mostly consumed invertebrates such as crabs (Potamonautes sidneyi) and Odonata larvae, while consuming only a small proportion of estuary-associated fish. Fatty acid analysis only showed a direct connection between the fatty acid profiles of largemouth bass and those of M. capensis and M. falciformis. The acoustic telemetry results indicated that some M. salmoides individuals periodically move into the upper reaches of the estuary following river flood events. The results obtained from all these approaches highlight the risk posed by largemouth bass introductions on indigenous fish species, particularly those that enter the areas occupied by these top predators.
- Full Text:
- Authors: Magoro, Mandla Leon
- Date: 2014
- Subjects: Largemouth bass -- South Africa -- Port Alfred , Largemouth bass -- Food -- South Africa -- Port Alfred , Estuarine fishes -- South Africa -- Port Alfred , Estuarine fishes -- Predators of , Centrarchidae , Fishes -- Effect of human beings on
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5851 , http://hdl.handle.net/10962/d1011939 , Largemouth bass -- South Africa -- Port Alfred , Largemouth bass -- Food -- South Africa -- Port Alfred , Estuarine fishes -- South Africa -- Port Alfred , Estuarine fishes -- Predators of , Centrarchidae , Fishes -- Effect of human beings on
- Description: Estuaries serve as nursery areas for a large number of estuary-associated fish species. Some of these taxa also use river catchments as nursery areas. During the upstream migration of this latter group, the juveniles are prone to predation by native and alien predatory fish inhabiting the system. The rate of invasion of ecosystems by alien organisms can be directly linked to anthropogenic influences, including both intentional and unintentional introductions by alien organisms into new regions. The largemouth bass, Micropterus salmoides, is a facultative piscivorous fish that has been successfully introduced worldwide for the main purpose of sport fishing. Where introduced, it has been found to negatively impact native fish and invertebrate species through predation, competitive exclusion and displacement of indigenous fish species. The aim of this thesis was to investigate the predatory impact of largemouth bass on the estuary-associated Cape moony Monodactylus falciformis, Cape stumpnose Rhabdosargus holubi and freshwater mullet Myxus capensis in the lower Kowie River of the Eastern Cape Province, South Africa. A combination of approaches was employed during this study. Stomach contents, stable isotopes and fatty acid analyses were employed for the reconstruction of the diet of largemouth bass. Acoustic telemetry was used to elucidate largemouth bass movements, particularly their ability to enter the upper reaches of the Kowie Estuary. Stomach contents and stable isotopes analyses showed that M. salmoides exhibit an ontogenic shift in diet, with small and medium sized individuals consuming the higher proportion of fish prey, while large sized individuals mostly consumed invertebrates such as crabs (Potamonautes sidneyi) and Odonata larvae, while consuming only a small proportion of estuary-associated fish. Fatty acid analysis only showed a direct connection between the fatty acid profiles of largemouth bass and those of M. capensis and M. falciformis. The acoustic telemetry results indicated that some M. salmoides individuals periodically move into the upper reaches of the estuary following river flood events. The results obtained from all these approaches highlight the risk posed by largemouth bass introductions on indigenous fish species, particularly those that enter the areas occupied by these top predators.
- Full Text:
Predicting the geographic distribution of Lucilia sericata and Lucilia cuprina (Diptera Calliphoridae) in South Africa
- Williams, Kirstin A, Richards, Cameron S, Villet, Martin H
- Authors: Williams, Kirstin A , Richards, Cameron S , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440681 , vital:73803 , https://hdl.handle.net/10520/EJC158017
- Description: Lucilia sericata (Meigen, 1826) and Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae: Luciliinae) have medical, veterinary and forensic importance. Knowing their distribution in South Africa would allow more effective management and utilisation of these flies. Their predicted geographic distributions in South Africa were modelled using maximum entropy analysis of selected climatic variables. The most important environmental variables in modelling the distributions were the magnitude of monthly rainfall and the magnitude of the monthly maximum temperature for L. sericata and the seasonal variation in monthly mean humidity and magnitude of monthly rainfall for L. cuprina. A clear geographical bias was shown in museum records and supports the need for focused surveys. There was no correlation between the predicted distribution of L. cuprina and sheep farming in South Africa, nor between the predicted distribution of L. sericata and human population density. Although their patterns of occurrence differed, both species are widely distributed in South Africa and therefore one cannot identify these flies by locality alone - morphological or molecular identification is necessary.
- Full Text:
- Authors: Williams, Kirstin A , Richards, Cameron S , Villet, Martin H
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/440681 , vital:73803 , https://hdl.handle.net/10520/EJC158017
- Description: Lucilia sericata (Meigen, 1826) and Lucilia cuprina (Wiedemann, 1830) (Diptera: Calliphoridae: Luciliinae) have medical, veterinary and forensic importance. Knowing their distribution in South Africa would allow more effective management and utilisation of these flies. Their predicted geographic distributions in South Africa were modelled using maximum entropy analysis of selected climatic variables. The most important environmental variables in modelling the distributions were the magnitude of monthly rainfall and the magnitude of the monthly maximum temperature for L. sericata and the seasonal variation in monthly mean humidity and magnitude of monthly rainfall for L. cuprina. A clear geographical bias was shown in museum records and supports the need for focused surveys. There was no correlation between the predicted distribution of L. cuprina and sheep farming in South Africa, nor between the predicted distribution of L. sericata and human population density. Although their patterns of occurrence differed, both species are widely distributed in South Africa and therefore one cannot identify these flies by locality alone - morphological or molecular identification is necessary.
- Full Text:
Pregnancy among young women in South Africa
- Macleod, Catriona I, Tracey, Tiffany
- Authors: Macleod, Catriona I , Tracey, Tiffany
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434371 , vital:73052 , ISBN 978-1-4899-8025-0 , https://doi.org/10.1007/978-1-4899-8026-7
- Description: In 1994, South Africa witnessed its first democratic elections after centuries of colonial and then apartheid rule. As time passes since that euphoric moment in 1994, the difficulties of transformation have become evident. In terms of sexual and reproductive health, HIV/AIDS is acknowledged as one of the most significant challenges, with South Africa having one of the highest infection rates globally. Pregnancy among teenage women is receiving increasing attention as well. For example, public concern has been expressed that the recently introduced Child Support Grant (CSG) acts as a ‘perverse incentive’ for young women to bear children. This emotional claim was refuted by separately commissioned reviews of research on girls who received the grant. National statistics paint an interesting picture that negates the popular opinion in South Africa that rates of teenage pregnancy and childbearing are escalating. The 1998, the South African Demographic and Health Survey (SADHS) indicated that 35 % of women had had a child by the age of 19 years, while in the 2003 SADHS survey, this had decreased to 27 %. The rights-based approach adopted by the South African government to sexual and reproductive health enshrines a young woman’s right to prevent an unwanted pregnancy, to plan a pregnancy with her partner should they wish, to make an independent decision concerning the outcome of a pregnancy, to terminate that pregnancy safely should she wish, and to access non-discriminatory prenatal and postnatal care should she take the pregnancy to term. While there are still many obstacles and challenges associated with the issues of ‘adolescent pregnancy,’ it is important to remember the success represented by, and that arises from, this rights-based legislation.
- Full Text:
- Authors: Macleod, Catriona I , Tracey, Tiffany
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/434371 , vital:73052 , ISBN 978-1-4899-8025-0 , https://doi.org/10.1007/978-1-4899-8026-7
- Description: In 1994, South Africa witnessed its first democratic elections after centuries of colonial and then apartheid rule. As time passes since that euphoric moment in 1994, the difficulties of transformation have become evident. In terms of sexual and reproductive health, HIV/AIDS is acknowledged as one of the most significant challenges, with South Africa having one of the highest infection rates globally. Pregnancy among teenage women is receiving increasing attention as well. For example, public concern has been expressed that the recently introduced Child Support Grant (CSG) acts as a ‘perverse incentive’ for young women to bear children. This emotional claim was refuted by separately commissioned reviews of research on girls who received the grant. National statistics paint an interesting picture that negates the popular opinion in South Africa that rates of teenage pregnancy and childbearing are escalating. The 1998, the South African Demographic and Health Survey (SADHS) indicated that 35 % of women had had a child by the age of 19 years, while in the 2003 SADHS survey, this had decreased to 27 %. The rights-based approach adopted by the South African government to sexual and reproductive health enshrines a young woman’s right to prevent an unwanted pregnancy, to plan a pregnancy with her partner should they wish, to make an independent decision concerning the outcome of a pregnancy, to terminate that pregnancy safely should she wish, and to access non-discriminatory prenatal and postnatal care should she take the pregnancy to term. While there are still many obstacles and challenges associated with the issues of ‘adolescent pregnancy,’ it is important to remember the success represented by, and that arises from, this rights-based legislation.
- Full Text:
Preliminary thoughts on services without servers
- Machanick, Philip, Hunt, Kieran
- Authors: Machanick, Philip , Hunt, Kieran
- Date: 2014
- Language: English
- Type: Conference paper
- Identifier: vital:6612 , http://hdl.handle.net/10962/d1014082
- Description: Warehouse-scale computing supports cloud-based services such as shared disk space, computation services and social networks. Although warehouse-scale computing is inexpensive per user, the cost to entry is high, and the pressures to generate revenues to cover costs leads service providers to pursue monetizing services aggressively. In this paper, we explore some ideas for removing the need for central servers by exploiting peer-to-peer technologies.
- Full Text:
- Authors: Machanick, Philip , Hunt, Kieran
- Date: 2014
- Language: English
- Type: Conference paper
- Identifier: vital:6612 , http://hdl.handle.net/10962/d1014082
- Description: Warehouse-scale computing supports cloud-based services such as shared disk space, computation services and social networks. Although warehouse-scale computing is inexpensive per user, the cost to entry is high, and the pressures to generate revenues to cover costs leads service providers to pursue monetizing services aggressively. In this paper, we explore some ideas for removing the need for central servers by exploiting peer-to-peer technologies.
- Full Text:
Primary Teachers’ Experiences Relating to the Administration Processes of High-stakes Testing The Case of Mathematics Annual National Assessments
- Graven, Mellony, Venkat, Hamsa
- Authors: Graven, Mellony , Venkat, Hamsa
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/482466 , vital:78654 , https://doi.org/10.1080/10288457.2014.965406
- Description: In this paper we highlight teacher experiences of the administration of high-stakes testing, in particular, of the 2012 Annual National Assessments (ANAs). The exploration is based on data gathered across two primary numeracy teacher development projects in the Eastern Cape and Gauteng in the form of open-ended questionnaires designed to elicit teacher experiences of the 2012 Numeracy ANAs (at Grades 1–3) and Mathematics ANAs (Grades 4–6). Fifty-four teachers across 21 schools (including fee-paying and non-fee-paying schools) completed the questionnaire. Using a grounded approach to the analysis of data, we note that, while teachers state support for the purpose of the ANAs ,several concerns emerge in relation to their administration. These concerns fall largely into two categories: concern for learner experiences and concern for the implications of the administration processes (including the use of exemplars and the marking process) for teacher practices. The primary purpose of the paper is to raise awareness of the need for further discussion and research into the way in which ANAs result in possible unintended consequences.
- Full Text:
- Authors: Graven, Mellony , Venkat, Hamsa
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/482466 , vital:78654 , https://doi.org/10.1080/10288457.2014.965406
- Description: In this paper we highlight teacher experiences of the administration of high-stakes testing, in particular, of the 2012 Annual National Assessments (ANAs). The exploration is based on data gathered across two primary numeracy teacher development projects in the Eastern Cape and Gauteng in the form of open-ended questionnaires designed to elicit teacher experiences of the 2012 Numeracy ANAs (at Grades 1–3) and Mathematics ANAs (Grades 4–6). Fifty-four teachers across 21 schools (including fee-paying and non-fee-paying schools) completed the questionnaire. Using a grounded approach to the analysis of data, we note that, while teachers state support for the purpose of the ANAs ,several concerns emerge in relation to their administration. These concerns fall largely into two categories: concern for learner experiences and concern for the implications of the administration processes (including the use of exemplars and the marking process) for teacher practices. The primary purpose of the paper is to raise awareness of the need for further discussion and research into the way in which ANAs result in possible unintended consequences.
- Full Text:
Primary wing-moult and site fidelity in South African mousebirds (Coliidae)
- Craig, Adrian J F K, Bonnevie, Bo T, Hulley, Patrick E, Underhill, George D
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hulley, Patrick E , Underhill, George D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449474 , vital:74824 , https://doi.org/10.2989/00306525.2014.931310
- Description: Based on large samples of birds mist-netted in the Eastern Cape and the Western Cape, moult of the primary remiges in both Speckled Mousebirds Colius striatus and Red-faced Mousebirds Urocolius indicus occurred throughout the year with no regional or seasonal patterns evident. The same picture emerged for the White-backed Mousebird Colius colius in the Western Cape. This aseasonality of wing-moult for all three species in South Africa was further supported by the full data set of moult records available in the Safring database. We were thus unable to use the Underhill–Zucchini model to estimate the moult parameters for these species, but an extended moult period seems likely. Recapture data for the Eastern Cape strongly suggest that Speckled Mousebirds are resident or revisit sites frequently, whereas this is not the case for Red-faced Mousebirds.
- Full Text:
- Authors: Craig, Adrian J F K , Bonnevie, Bo T , Hulley, Patrick E , Underhill, George D
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/449474 , vital:74824 , https://doi.org/10.2989/00306525.2014.931310
- Description: Based on large samples of birds mist-netted in the Eastern Cape and the Western Cape, moult of the primary remiges in both Speckled Mousebirds Colius striatus and Red-faced Mousebirds Urocolius indicus occurred throughout the year with no regional or seasonal patterns evident. The same picture emerged for the White-backed Mousebird Colius colius in the Western Cape. This aseasonality of wing-moult for all three species in South Africa was further supported by the full data set of moult records available in the Safring database. We were thus unable to use the Underhill–Zucchini model to estimate the moult parameters for these species, but an extended moult period seems likely. Recapture data for the Eastern Cape strongly suggest that Speckled Mousebirds are resident or revisit sites frequently, whereas this is not the case for Red-faced Mousebirds.
- Full Text:
Primary wing-moult in relation to body-mass, wing-length and latitude in four insectivorous passerines from southern Africa
- Bonnevie, Bo T, Craig, Adrian J F K
- Authors: Bonnevie, Bo T , Craig, Adrian J F K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465424 , vital:76609 , https://doi.org/10.1071/MU13072
- Description: In southern African passerine birds, the timing of moult often varies regionally in relation to breeding season and patterns of rainfall, and may also differ between sexes in sexually dimorphic species. However, the relationship between feeding ecology andmoult has not been studied in this region. We investigated primary-moult, body-mass and wing-length in four southern African passerines belonging to a feeding guild of hawking (sallying) insectivores, using bird-banding (ringing) data. The timing of wing-moult, from December to April throughout the region, was very similar in all four species, in contrast to other sympatric species, which moult at different times in summer-and winter-rainfall regions. For each species the duration of moult decreased southwards, as did wing-length corrected for body-mass. There was no difference between the sexes in the timing or duration of wing-moult, even in sexually dimorphic species, but juveniles generally started moult later than adults and completed their moult more rapidly. Our results suggest that foraging ecology and life-history traits of insectivorous hawkers may constrain the timing of moult.
- Full Text:
- Authors: Bonnevie, Bo T , Craig, Adrian J F K
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/465424 , vital:76609 , https://doi.org/10.1071/MU13072
- Description: In southern African passerine birds, the timing of moult often varies regionally in relation to breeding season and patterns of rainfall, and may also differ between sexes in sexually dimorphic species. However, the relationship between feeding ecology andmoult has not been studied in this region. We investigated primary-moult, body-mass and wing-length in four southern African passerines belonging to a feeding guild of hawking (sallying) insectivores, using bird-banding (ringing) data. The timing of wing-moult, from December to April throughout the region, was very similar in all four species, in contrast to other sympatric species, which moult at different times in summer-and winter-rainfall regions. For each species the duration of moult decreased southwards, as did wing-length corrected for body-mass. There was no difference between the sexes in the timing or duration of wing-moult, even in sexually dimorphic species, but juveniles generally started moult later than adults and completed their moult more rapidly. Our results suggest that foraging ecology and life-history traits of insectivorous hawkers may constrain the timing of moult.
- Full Text:
Prioritisation of potential agents for the biological control of the invasive alien weed, Pereskia aculeata (Cactaceae), in South Africa
- Paterson, Iain D, Vitorino, Marcello D, de Cristo, S C, Martin, Grant D, Hill, Martin P
- Authors: Paterson, Iain D , Vitorino, Marcello D , de Cristo, S C , Martin, Grant D , Hill, Martin P
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76946 , vital:30644 , https://doi.org/10.1080/09583157.2013.864382
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien species in South Africa that is native in Central and South America. In South Africa, P. aculeata outcompetes native plant species leading to a reduction in biodiversity at infested sites. Herbicidal and mechanical control of the plant is ineffective and unsustainable, so biological control is considered the only potential solution. Climatic matching and genotype matching indicated that the most appropriate regions in which to collect biological control agents were Santa Catarina and Rio de Janeiro provinces in Southern Brazil. Surveys throughout the native distribution resulted in 15 natural enemy species that were associated with the plant. Field host range data, as well as previous host plant records, were used to prioritise which of the species were most likely to be suitably host specific for release in South Africa. The mode of damage was used to determine which species were most likely to be damaging and effective if released. The most promising species prioritised for further study, including host specificity and impact studies, were the stem-wilter Catorhintha schaffneri Brailovsky and Garcia (Coreidae); the stem boring species Acanthodoxus machacalis Martins and Monné (Cerambycidae), Cryptorhynchus sp. (Curculionidae) and Maracayia chlorisalis (Walker) (Crambidae) and the fruit galler Asphondylia sp. (Cecidomyiidae). By prioritising the potential biological control agents that are most likely to be host-specific and damaging, the risk of conducting host specificity testing on unsuitable or ineffective biological control agents is reduced.
- Full Text:
- Authors: Paterson, Iain D , Vitorino, Marcello D , de Cristo, S C , Martin, Grant D , Hill, Martin P
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76946 , vital:30644 , https://doi.org/10.1080/09583157.2013.864382
- Description: Pereskia aculeata Miller (Cactaceae) is an invasive alien species in South Africa that is native in Central and South America. In South Africa, P. aculeata outcompetes native plant species leading to a reduction in biodiversity at infested sites. Herbicidal and mechanical control of the plant is ineffective and unsustainable, so biological control is considered the only potential solution. Climatic matching and genotype matching indicated that the most appropriate regions in which to collect biological control agents were Santa Catarina and Rio de Janeiro provinces in Southern Brazil. Surveys throughout the native distribution resulted in 15 natural enemy species that were associated with the plant. Field host range data, as well as previous host plant records, were used to prioritise which of the species were most likely to be suitably host specific for release in South Africa. The mode of damage was used to determine which species were most likely to be damaging and effective if released. The most promising species prioritised for further study, including host specificity and impact studies, were the stem-wilter Catorhintha schaffneri Brailovsky and Garcia (Coreidae); the stem boring species Acanthodoxus machacalis Martins and Monné (Cerambycidae), Cryptorhynchus sp. (Curculionidae) and Maracayia chlorisalis (Walker) (Crambidae) and the fruit galler Asphondylia sp. (Cecidomyiidae). By prioritising the potential biological control agents that are most likely to be host-specific and damaging, the risk of conducting host specificity testing on unsuitable or ineffective biological control agents is reduced.
- Full Text:
Prioritising native fish populations for conservation using genetics in the Groot Marico catchment, North West Province, South Africa
- Authors: Van der Walt, Kerry-Ann
- Date: 2014
- Subjects: Native fishes Fishery management -- South Africa -- North West Fish populations Fishes -- Conservation -- South Africa -- Western Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/69102 , vital:29390
- Description: The Groot Marico catchment in the North West Province is a National Freshwater Ecosystem Priority Area (NFEPA) because it represents unique landscape features with unique biodiversity that are considered to be of special ecological significance. Three native freshwater species Amphilius uranoscopus, Chiloglanis pretoriae and Barbus motebensis, have high local conservation importance and B. motebensis is endemic to the catchment and is IUCN-listed as vulnerable. The main objective of this study is to contribute towards the effective conservation of these three species in the Groot Marico River system by assessing their genetic structure to determine whether tributary populations of the three species comprise of one genetic population or whether they are divided into genetically distinct subpopulations, in order to prioritise areas for conservation. The central null hypothesis was that there is no genetic differentiation between tributary populations (i.e., panmixia) of B. motebensis, A. uranoscopus and C. pretoriae in the Groot Marico catchment, North West Province. In total, 80 individuals per species were collected, targeting at least 10 individuals per population from a total of eight populations (seven tributaries and the Groot Marico main stem) and across the study area. Samples were collected by electrofishing and specimens were euthanized using an overdose of clove oil. A sample of muscle tissue was removed for genetic evaluation and the remainder of the specimens served as voucher specimens. For the genetic evaluation, mitochondrial (ND2, cyt b) and nuclear (S7) genes were used. Genetic techniques used were DNA extraction, polymerase chain reaction (PCR), purification and sequencing. From the 240 individuals collected, 123 sequences for B. motebensis, 111 sequences for A. uranoscopus and 103 sequences for C. pretoriae were analysed across all three genes. Statistical analysis included looking at cleaned sequences in order to obtain models using MODELTEST (version 3.06). Population structuring and phylogeographic analysis was performed in Arlequin (version 2000), TCS (version 1.2.1) and PAUP*. Results indicated that for B. motebensis the null hypothesis could be rejected as there were two distinct lineages (the Draai and Eastern lineages) that demonstrated significant divergence in both the ND2 and S7 genes, suggesting historical isolation. The low divergence in the mitochondrial cytochrome b gene (0% < D < 0.8%) suggests that this isolation is not very old and is probably not comparable to species level differentiation. The null hypothesis was also rejected for A. uranoscopus as there were also significant levels of differentiation between tributary populations resulting in the identification of two lineages (the Ribbok and Western lineages). However, for C. pretoriae, the null hypothesis could not be rejected as there was no genetic differentiation between tributary populations i.e., one panmictic population. Therefore, due to each species showing different genetic structuring within the tributary populations, more than one priority area for conservation needs to be implemented. These priority areas of conservation where therefore evaluated based on the current conservation status of the species (B. motebensis being vulnerable on the IUCN Red List), the number of Evolutionary Significant Units for each species and the overall genetic diversity of all three species in the Groot Marico catchment. In total, four tributary populations were conservation priorities areas, these were the Draai, Vanstraatens, Ribbok and Kaaloog tributaries. The Draai, Vanstraatens and Kaaloog tributaries were selected as priority areas for B. motebensis (B. motebensis is considered to be the most vulnerable of all three species). The Draai tributary was selected due to the B. motebensis population within the tributary showing isolation from the rest of the tributary populations. In order to conserve B. motebensis from the Southern lineage, the Vanstraatens and Kaaloog tributaries were selected. Reasons for selecting these two specific tributaries within the Southern lineage were that the Vanstraatens tributary had unique alleles (three Evolutionary Significant Units) for B. motebensis and the Kaaloog tributary had high genetic diversity (HD = 0.889, ND2 gene) when compared to the other tributary populations. The Ribbok and Vanstraatens tributaries were selected as priority areas for the conservation of A. uranoscopus. The Ribbok tributary was selected as it showed isolation from the rest of the tributary populations, as seen with the Draai tributary (B. motebensis) and the Vanstraatens tributary was selected to represent the Western lineage as it had the highest diversity for both genes (ND2 and S7). The Ribbok tributary has the highest prioritisation when compared to the Vanstraatens tributary. Chiloglanis pretoriae occurs within the Draai, Vanstraatens, Ribbok and Kaaloog tributaries, therefore by prioritising these tributaries for conservation, C. pretoriae will in turn be conserved.
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- Authors: Van der Walt, Kerry-Ann
- Date: 2014
- Subjects: Native fishes Fishery management -- South Africa -- North West Fish populations Fishes -- Conservation -- South Africa -- Western Cape
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/69102 , vital:29390
- Description: The Groot Marico catchment in the North West Province is a National Freshwater Ecosystem Priority Area (NFEPA) because it represents unique landscape features with unique biodiversity that are considered to be of special ecological significance. Three native freshwater species Amphilius uranoscopus, Chiloglanis pretoriae and Barbus motebensis, have high local conservation importance and B. motebensis is endemic to the catchment and is IUCN-listed as vulnerable. The main objective of this study is to contribute towards the effective conservation of these three species in the Groot Marico River system by assessing their genetic structure to determine whether tributary populations of the three species comprise of one genetic population or whether they are divided into genetically distinct subpopulations, in order to prioritise areas for conservation. The central null hypothesis was that there is no genetic differentiation between tributary populations (i.e., panmixia) of B. motebensis, A. uranoscopus and C. pretoriae in the Groot Marico catchment, North West Province. In total, 80 individuals per species were collected, targeting at least 10 individuals per population from a total of eight populations (seven tributaries and the Groot Marico main stem) and across the study area. Samples were collected by electrofishing and specimens were euthanized using an overdose of clove oil. A sample of muscle tissue was removed for genetic evaluation and the remainder of the specimens served as voucher specimens. For the genetic evaluation, mitochondrial (ND2, cyt b) and nuclear (S7) genes were used. Genetic techniques used were DNA extraction, polymerase chain reaction (PCR), purification and sequencing. From the 240 individuals collected, 123 sequences for B. motebensis, 111 sequences for A. uranoscopus and 103 sequences for C. pretoriae were analysed across all three genes. Statistical analysis included looking at cleaned sequences in order to obtain models using MODELTEST (version 3.06). Population structuring and phylogeographic analysis was performed in Arlequin (version 2000), TCS (version 1.2.1) and PAUP*. Results indicated that for B. motebensis the null hypothesis could be rejected as there were two distinct lineages (the Draai and Eastern lineages) that demonstrated significant divergence in both the ND2 and S7 genes, suggesting historical isolation. The low divergence in the mitochondrial cytochrome b gene (0% < D < 0.8%) suggests that this isolation is not very old and is probably not comparable to species level differentiation. The null hypothesis was also rejected for A. uranoscopus as there were also significant levels of differentiation between tributary populations resulting in the identification of two lineages (the Ribbok and Western lineages). However, for C. pretoriae, the null hypothesis could not be rejected as there was no genetic differentiation between tributary populations i.e., one panmictic population. Therefore, due to each species showing different genetic structuring within the tributary populations, more than one priority area for conservation needs to be implemented. These priority areas of conservation where therefore evaluated based on the current conservation status of the species (B. motebensis being vulnerable on the IUCN Red List), the number of Evolutionary Significant Units for each species and the overall genetic diversity of all three species in the Groot Marico catchment. In total, four tributary populations were conservation priorities areas, these were the Draai, Vanstraatens, Ribbok and Kaaloog tributaries. The Draai, Vanstraatens and Kaaloog tributaries were selected as priority areas for B. motebensis (B. motebensis is considered to be the most vulnerable of all three species). The Draai tributary was selected due to the B. motebensis population within the tributary showing isolation from the rest of the tributary populations. In order to conserve B. motebensis from the Southern lineage, the Vanstraatens and Kaaloog tributaries were selected. Reasons for selecting these two specific tributaries within the Southern lineage were that the Vanstraatens tributary had unique alleles (three Evolutionary Significant Units) for B. motebensis and the Kaaloog tributary had high genetic diversity (HD = 0.889, ND2 gene) when compared to the other tributary populations. The Ribbok and Vanstraatens tributaries were selected as priority areas for the conservation of A. uranoscopus. The Ribbok tributary was selected as it showed isolation from the rest of the tributary populations, as seen with the Draai tributary (B. motebensis) and the Vanstraatens tributary was selected to represent the Western lineage as it had the highest diversity for both genes (ND2 and S7). The Ribbok tributary has the highest prioritisation when compared to the Vanstraatens tributary. Chiloglanis pretoriae occurs within the Draai, Vanstraatens, Ribbok and Kaaloog tributaries, therefore by prioritising these tributaries for conservation, C. pretoriae will in turn be conserved.
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