Bioinformatics education—perspectives and challenges out of Africa
- Tastan Bishop, Özlem, Adebiyi, Ezekiel F, Alzohairy, Ahmed M, Everett, Dean B, Ghedira, Kais, Ghouila, Amel, Kumuthini, Judit, Mulder, Nicola J, Panji, Sumir, Patterton, Hugh-G
- Authors: Tastan Bishop, Özlem , Adebiyi, Ezekiel F , Alzohairy, Ahmed M , Everett, Dean B , Ghedira, Kais , Ghouila, Amel , Kumuthini, Judit , Mulder, Nicola J , Panji, Sumir , Patterton, Hugh-G
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123244 , vital:35420 , https://doi.10.1093/bib/bbu022
- Description: The discipline of bioinformatics has developed rapidly since the complete sequencing of the first genomes in the 1990s.The development of many high-throughput techniques during the last decades has ensured that bioinformatics has grown into a discipline that overlaps with, and is required for, the modern practice of virtually every field in the life sciences. This has placed a scientific premium on the availability of skilled bioinformaticians, a qualification that is extremely scarce on the African continent. The reasons for this are numerous, although the absence of a skilled bioinformatician at academic institutions to initiate a training process and build sustained capacity seems to be a common African shortcoming.This dearth of bioinformatics expertise has had a knock-on effect on the establishment of many modern high-throughput projects at African institutes, including the comprehensive and systematic analysis of genomes from African populations, which are among the most genetically diverse anywhere on the planet. Recent funding initiatives from the National Institutes of Health and theWellcomeTrust are aimed at ameliorating this shortcoming. In this paper, we discuss the problems that have limited the establishment of the bioinformatics field in Africa, as well as propose specific actions that will help with the education and training of bioinformaticians on the continent. This is an absolute requirement in anticipation of a boom in high-throughput approaches to human health issues unique to data from African populations.
- Full Text:
- Date Issued: 2014
- Authors: Tastan Bishop, Özlem , Adebiyi, Ezekiel F , Alzohairy, Ahmed M , Everett, Dean B , Ghedira, Kais , Ghouila, Amel , Kumuthini, Judit , Mulder, Nicola J , Panji, Sumir , Patterton, Hugh-G
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/123244 , vital:35420 , https://doi.10.1093/bib/bbu022
- Description: The discipline of bioinformatics has developed rapidly since the complete sequencing of the first genomes in the 1990s.The development of many high-throughput techniques during the last decades has ensured that bioinformatics has grown into a discipline that overlaps with, and is required for, the modern practice of virtually every field in the life sciences. This has placed a scientific premium on the availability of skilled bioinformaticians, a qualification that is extremely scarce on the African continent. The reasons for this are numerous, although the absence of a skilled bioinformatician at academic institutions to initiate a training process and build sustained capacity seems to be a common African shortcoming.This dearth of bioinformatics expertise has had a knock-on effect on the establishment of many modern high-throughput projects at African institutes, including the comprehensive and systematic analysis of genomes from African populations, which are among the most genetically diverse anywhere on the planet. Recent funding initiatives from the National Institutes of Health and theWellcomeTrust are aimed at ameliorating this shortcoming. In this paper, we discuss the problems that have limited the establishment of the bioinformatics field in Africa, as well as propose specific actions that will help with the education and training of bioinformaticians on the continent. This is an absolute requirement in anticipation of a boom in high-throughput approaches to human health issues unique to data from African populations.
- Full Text:
- Date Issued: 2014
Book Review: Community of insecurity
- Authors: Magadla, Siphokazi
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298606 , vital:57720 , xlink:href="https://doi.org/10.1080/02589001.2014.936174"
- Description: Laurie Nathan's Community of Insecurity is a thoughtful engagement with the ‘establishment, evolution and effectiveness of the regional security arrangements of the Southern African Development Community (SADC)’ (1). He argues that it is of ‘great significance and irony that many of the major disputes among member states have been around the orientation and strategies of peacemaking and regional security’. Nathan's empirical claims about the SADC security architecture are drawn from his ‘insider perspective’ due to his involvement in official efforts to design a common security regime in Southern Africa, which include his service as regional security advisor to the SADC Secretariat from 1992 to 1996, to the Foreign Minister of Mozambique Pascoal Mocumbi from 1994 to 1995, to the South African Minister of Defence Joe Modise and the Deputy Minister of Defence Ronnie Kasrils between 1994 and 1999 and to the Foreign Minister of Swaziland Albert Shabangu when he oversaw the SADC Organ on Politics, Defence and Security Cooperation in 1999–2000 (12–13). This ‘insider’ view has allowed him to make a compelling challenge to current theoretical debates about SADC's status as a security community, that is, a community with an affinity amongst member states that is ‘so strong that they enjoy dependable expectations of peaceful change and thus regard the prospect of war among them as inconceivable’(129). While other commentators see SADC as either a ‘nascent’, ‘embryonic’ or ‘emerging’ security community, Nathan argues forcefully that ‘this perspective is mistaken’ as SADC continues to be demonstrative of a what he describes as a ‘community of insecurity’.
- Full Text:
- Date Issued: 2014
- Authors: Magadla, Siphokazi
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/298606 , vital:57720 , xlink:href="https://doi.org/10.1080/02589001.2014.936174"
- Description: Laurie Nathan's Community of Insecurity is a thoughtful engagement with the ‘establishment, evolution and effectiveness of the regional security arrangements of the Southern African Development Community (SADC)’ (1). He argues that it is of ‘great significance and irony that many of the major disputes among member states have been around the orientation and strategies of peacemaking and regional security’. Nathan's empirical claims about the SADC security architecture are drawn from his ‘insider perspective’ due to his involvement in official efforts to design a common security regime in Southern Africa, which include his service as regional security advisor to the SADC Secretariat from 1992 to 1996, to the Foreign Minister of Mozambique Pascoal Mocumbi from 1994 to 1995, to the South African Minister of Defence Joe Modise and the Deputy Minister of Defence Ronnie Kasrils between 1994 and 1999 and to the Foreign Minister of Swaziland Albert Shabangu when he oversaw the SADC Organ on Politics, Defence and Security Cooperation in 1999–2000 (12–13). This ‘insider’ view has allowed him to make a compelling challenge to current theoretical debates about SADC's status as a security community, that is, a community with an affinity amongst member states that is ‘so strong that they enjoy dependable expectations of peaceful change and thus regard the prospect of war among them as inconceivable’(129). While other commentators see SADC as either a ‘nascent’, ‘embryonic’ or ‘emerging’ security community, Nathan argues forcefully that ‘this perspective is mistaken’ as SADC continues to be demonstrative of a what he describes as a ‘community of insecurity’.
- Full Text:
- Date Issued: 2014
Breast cancer: current developments in molecular approaches to diagnosis and treatment
- de la Mare, Jo-Anne, Contu, Lara, Hunter, Morgan C, Moyo, Buhle, Sterrenberg, Jason N, Dhanani, Karim C H, Mutsvunguma, Lorraine Z, Edkins, Adrienne L
- Authors: de la Mare, Jo-Anne , Contu, Lara , Hunter, Morgan C , Moyo, Buhle , Sterrenberg, Jason N , Dhanani, Karim C H , Mutsvunguma, Lorraine Z , Edkins, Adrienne L
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164819 , vital:41175 , DOI: 10.2174/15748928113086660046
- Description: Due to the high heterogeneity of breast cancers, numerous recent patents describe improved methods of detection and classification which promise better patient prognosis and treatment. In particular, there has been a shift towards more effective genetic screening to identify specific mutations associated with breast tumours, which may lead to “personalised medicine” with improved outcomes. Two challenging areas of breast cancer research involve the development of treatments for the highly aggressive triple negative breast cancer subtype as well as the chemotherapy-resistant cancer stem cell subpopulation. In addition, despite numerous recent advances in breast cancer treatment in woman, male breast cancer remains poorly understood and there are limited therapies available which are developed specifically for men. This review serves to report on important developments in the treatment of breast malignancies patented in the past two years as well as to highlight the current gaps in the field of breast cancer therapeutics and areas which require further study.
- Full Text:
- Date Issued: 2014
- Authors: de la Mare, Jo-Anne , Contu, Lara , Hunter, Morgan C , Moyo, Buhle , Sterrenberg, Jason N , Dhanani, Karim C H , Mutsvunguma, Lorraine Z , Edkins, Adrienne L
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164819 , vital:41175 , DOI: 10.2174/15748928113086660046
- Description: Due to the high heterogeneity of breast cancers, numerous recent patents describe improved methods of detection and classification which promise better patient prognosis and treatment. In particular, there has been a shift towards more effective genetic screening to identify specific mutations associated with breast tumours, which may lead to “personalised medicine” with improved outcomes. Two challenging areas of breast cancer research involve the development of treatments for the highly aggressive triple negative breast cancer subtype as well as the chemotherapy-resistant cancer stem cell subpopulation. In addition, despite numerous recent advances in breast cancer treatment in woman, male breast cancer remains poorly understood and there are limited therapies available which are developed specifically for men. This review serves to report on important developments in the treatment of breast malignancies patented in the past two years as well as to highlight the current gaps in the field of breast cancer therapeutics and areas which require further study.
- Full Text:
- Date Issued: 2014
Can δ15N and δ13C stable isotopes and fatty acid signatures indicate changes in phytobenthos composition on an artificial substrate?
- Dalu, Tatenda, Froneman, P William
- Authors: Dalu, Tatenda , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68086 , vital:29197 , https://doi.org/10.2989/16085914.2014.974018
- Description: Publisher version , Temporal changes in fatty acid composition and δ15N, δ13C stable isotope values of the phytobenthos growing on artificial clay substrates under natural conditions over a 28-day period at an upstream and a downstream site in the Kowie River near Grahamstown were investigated in 2012. High concentrations of diatom markers 16:1ω7 and 20:5ω3 fatty acids were recorded, especially at the downstream site, reflecting the importance of diatoms in contributing to the phytobenthos communities at that station. After day 7 at the downstream site the average δ15N value of the phytobenthos was lighter, gradually increasing by ∼2‰ and ∼5‰ overall to heavier values on day 28. At the upstream site there were no significant changes (<1‰ increase) in δ15N values of the phytobenthos over time. Stable nitrogen (δ15N) and carbon (δ13C) signatures in the phytobenthos communities were significantly different between sites (one-way ANOVA; p < 0.001). The stable isotope values and fatty acid concentrations of phytobenthos at the downstream site were different to those of the phytobenthos at the upstream site, and they changed concurrently with changes in the phytobenthos community structure. At the downstream site there was a strong correlation of the δ15N of phytobenthos with nitrates (R = 0.56) and time (weeks; R = 0.81). However, the fatty acids were not specific enough to characterise the composition of phytobenthos communities. Other biomarker methods, such as stable isotopes and microscopic examination of the communities, were found to be useful. The results from this relatively small-scale tile experiment indicate the complexity of changes in fatty acid composition and δ15N, δ13C stable isotope values of a phytobenthos community. Stable isotope and fatty acid composition can be successfully used to map changes in phytobenthos composition and carbon and nitrogen flow patterns along a river continuum.
- Full Text: false
- Date Issued: 2014
- Authors: Dalu, Tatenda , Froneman, P William
- Date: 2014
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68086 , vital:29197 , https://doi.org/10.2989/16085914.2014.974018
- Description: Publisher version , Temporal changes in fatty acid composition and δ15N, δ13C stable isotope values of the phytobenthos growing on artificial clay substrates under natural conditions over a 28-day period at an upstream and a downstream site in the Kowie River near Grahamstown were investigated in 2012. High concentrations of diatom markers 16:1ω7 and 20:5ω3 fatty acids were recorded, especially at the downstream site, reflecting the importance of diatoms in contributing to the phytobenthos communities at that station. After day 7 at the downstream site the average δ15N value of the phytobenthos was lighter, gradually increasing by ∼2‰ and ∼5‰ overall to heavier values on day 28. At the upstream site there were no significant changes (<1‰ increase) in δ15N values of the phytobenthos over time. Stable nitrogen (δ15N) and carbon (δ13C) signatures in the phytobenthos communities were significantly different between sites (one-way ANOVA; p < 0.001). The stable isotope values and fatty acid concentrations of phytobenthos at the downstream site were different to those of the phytobenthos at the upstream site, and they changed concurrently with changes in the phytobenthos community structure. At the downstream site there was a strong correlation of the δ15N of phytobenthos with nitrates (R = 0.56) and time (weeks; R = 0.81). However, the fatty acids were not specific enough to characterise the composition of phytobenthos communities. Other biomarker methods, such as stable isotopes and microscopic examination of the communities, were found to be useful. The results from this relatively small-scale tile experiment indicate the complexity of changes in fatty acid composition and δ15N, δ13C stable isotope values of a phytobenthos community. Stable isotope and fatty acid composition can be successfully used to map changes in phytobenthos composition and carbon and nitrogen flow patterns along a river continuum.
- Full Text: false
- Date Issued: 2014
Carbon nanotube-enhanced photoelectrochemical properties of metallo-octacarboxyphthalocyanines
- Mphahlele, Nonhlanhla E, Le Roux, Lukas, Jafta, Charl J, Cele, Leskev, Mathe, Mkhulu K, Nyokong, Tebello, Kobayashi, Nagao, Ozoemena, Kenneth I
- Authors: Mphahlele, Nonhlanhla E , Le Roux, Lukas , Jafta, Charl J , Cele, Leskev , Mathe, Mkhulu K , Nyokong, Tebello , Kobayashi, Nagao , Ozoemena, Kenneth I
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241595 , vital:50953 , xlink:href="https://doi.org/10.1007/s10853-013-7710-1"
- Description: The photoelectrochemistry of metallo-octacarboxyphthalocyanines (MOCPc, where M = Zn or Si(OH)2) integrated with MWCNTs for the development of dye-sensitized solar cells (DSSCs) is reported. The DSSC performance (obtained from the photo-chronoamperometric and photo-impedimetric data) decreased as ZnOCPc > (OH)2SiOCPc. The incorporation of the MWCNTs on the surface of the TiO2 film (MOCPc–MWCNT systems) gave higher photocurrent density than the bare MOCPc complexes. Also, from the EIS results, the MOCPc–MWCNT hybrids gave faster charge transport kinetics (approximately three times faster) compared to the bare MOCPc complexes. The electron lifetime was slightly longer (ca. 6 ms) at the ZnOCPc systems than at the (OH)2SiOCPc system (ca. 4 ms) meaning that the presence of the MWCNTs on the surface of the TiO2 film did not show any significant improvement on preventing charge recombination process.
- Full Text:
- Date Issued: 2014
- Authors: Mphahlele, Nonhlanhla E , Le Roux, Lukas , Jafta, Charl J , Cele, Leskev , Mathe, Mkhulu K , Nyokong, Tebello , Kobayashi, Nagao , Ozoemena, Kenneth I
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241595 , vital:50953 , xlink:href="https://doi.org/10.1007/s10853-013-7710-1"
- Description: The photoelectrochemistry of metallo-octacarboxyphthalocyanines (MOCPc, where M = Zn or Si(OH)2) integrated with MWCNTs for the development of dye-sensitized solar cells (DSSCs) is reported. The DSSC performance (obtained from the photo-chronoamperometric and photo-impedimetric data) decreased as ZnOCPc > (OH)2SiOCPc. The incorporation of the MWCNTs on the surface of the TiO2 film (MOCPc–MWCNT systems) gave higher photocurrent density than the bare MOCPc complexes. Also, from the EIS results, the MOCPc–MWCNT hybrids gave faster charge transport kinetics (approximately three times faster) compared to the bare MOCPc complexes. The electron lifetime was slightly longer (ca. 6 ms) at the ZnOCPc systems than at the (OH)2SiOCPc system (ca. 4 ms) meaning that the presence of the MWCNTs on the surface of the TiO2 film did not show any significant improvement on preventing charge recombination process.
- Full Text:
- Date Issued: 2014
Career success for women academics in higher education: choices and challenges
- Authors: Obers, Nöelle Marie Thérèse
- Date: 2014
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61346 , vital:28017 , http://0-journals.co.za.wam.seals.ac.za/content/high/28/3/EJC159132
- Description: The aim of the research reported on in this article was to contribute to an understanding of how women academics experience career success; how their choices and challenges impact on their career advancement; and how the playing fields in academia can be levelled. Understanding the constraints and identifying enabling aspects may help women academics to overcome obstacles in their career development and be more represented in academia and ultimately in society. This research was a case study undertaken at one higher education institution (HEI), Rhodes University (RU). The data was collected from institutional documents; questionnaire data from women academics at the HEI; and in-depth interviews with six women academics. The data indicate that mentoring is a strategy to enhance levels of self-esteem and research productivity and ultimately improve the representation of women in leadership and senior positions.
- Full Text:
- Date Issued: 2014
- Authors: Obers, Nöelle Marie Thérèse
- Date: 2014
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/61346 , vital:28017 , http://0-journals.co.za.wam.seals.ac.za/content/high/28/3/EJC159132
- Description: The aim of the research reported on in this article was to contribute to an understanding of how women academics experience career success; how their choices and challenges impact on their career advancement; and how the playing fields in academia can be levelled. Understanding the constraints and identifying enabling aspects may help women academics to overcome obstacles in their career development and be more represented in academia and ultimately in society. This research was a case study undertaken at one higher education institution (HEI), Rhodes University (RU). The data was collected from institutional documents; questionnaire data from women academics at the HEI; and in-depth interviews with six women academics. The data indicate that mentoring is a strategy to enhance levels of self-esteem and research productivity and ultimately improve the representation of women in leadership and senior positions.
- Full Text:
- Date Issued: 2014
Challenges facing teachers in implementing alternative measures of discipline in schools: a case study of five secondary schools in the Umzimkhulu circuit of the Sisonke District in Kwazulu-Natal
- Authors: Zulu, Xolani Wycliff
- Date: 2014
- Subjects: School discipline , Secondary schools , Sisonke District -- Kwazulu-Natal, South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/11260/2393 , vital:41455
- Description: This dissertation is a report on a study that was conducted in rural schools of the Sisonke District in KwaZulu-Natal, a province of South Africa. The study covered the challenges experienced by teachers in implementing the alternative measures of discipline. The study was conducted because the researcher was the head of the disciplinary committee in the school where he was employed and he often dealt with disciplinary problems which usually occurred between the teachers, learners and SMTs. It was important to know from other schools, what problems they faced in implementing the alternative measures of discipline. The study used a qualitative research design in the form of a case study. Purposive sampling was used. The sample comprised 15 SMT members, and 20 post level 1 teachers, and the total number of participants was 35. Data was collected through observations which were followed by interviews. Qualitative methods were used to analyse data. This involved reduction and interpretation of data collected. The findings of the study highlighted the role that could be played by SMTs, teachers, parents, and the Department of Education in the smooth running of the school in dealing with the misunderstandings of alternative measures of discipline and so advance an effective work ethos. The study also illuminated the issue of negligence on the part of SMTs in enforcing the implementation of the alternative measures of discipline. There was a great need for school teachers to be well versed in the general legislation of the Department of Education so as to align themselves with the correct rules and regulations when they deal with disciplinary problems. , Thesis (MEd) -- Faculty of Humanities, Educational Management and Policy, 2014
- Full Text:
- Date Issued: 2014
- Authors: Zulu, Xolani Wycliff
- Date: 2014
- Subjects: School discipline , Secondary schools , Sisonke District -- Kwazulu-Natal, South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/11260/2393 , vital:41455
- Description: This dissertation is a report on a study that was conducted in rural schools of the Sisonke District in KwaZulu-Natal, a province of South Africa. The study covered the challenges experienced by teachers in implementing the alternative measures of discipline. The study was conducted because the researcher was the head of the disciplinary committee in the school where he was employed and he often dealt with disciplinary problems which usually occurred between the teachers, learners and SMTs. It was important to know from other schools, what problems they faced in implementing the alternative measures of discipline. The study used a qualitative research design in the form of a case study. Purposive sampling was used. The sample comprised 15 SMT members, and 20 post level 1 teachers, and the total number of participants was 35. Data was collected through observations which were followed by interviews. Qualitative methods were used to analyse data. This involved reduction and interpretation of data collected. The findings of the study highlighted the role that could be played by SMTs, teachers, parents, and the Department of Education in the smooth running of the school in dealing with the misunderstandings of alternative measures of discipline and so advance an effective work ethos. The study also illuminated the issue of negligence on the part of SMTs in enforcing the implementation of the alternative measures of discipline. There was a great need for school teachers to be well versed in the general legislation of the Department of Education so as to align themselves with the correct rules and regulations when they deal with disciplinary problems. , Thesis (MEd) -- Faculty of Humanities, Educational Management and Policy, 2014
- Full Text:
- Date Issued: 2014
Characterization and application of phthalocyanine-magnetic nanoparticle conjugates anchored to electrospun polyamide nanofibers
- Authors: Ledwaba, Mpho
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54610 , vital:26593
- Description: This work presents the syntheses, photophysical and photochemical characterization of zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc, 3) and its gadolinium oxide nanoparticle conjugate (4). By means of spectroscopic and microscopic characterization, the conjugation of the ZnTCPPc to the silica coated gadolinium oxide nanoparticles (Si-Gd2O3 NPs, 2) through an amide bond was confirmed. The thermal stability, morphology, nanoparticle sizes and their conjugates with the Pc were studied using ThermoGravimetric Analysis (TGA), Fourier Transform Infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and powder X-ray diffractometry (XRD). Conjugation of ZnTCPPc to the magnetic nanoparticles, proved to have a negligible effect on the photophysical parameters of the phthalocyanine, where a slight decrease in fluorescence and triplet quantum yields and lifetimes was observed. The singlet oxygen quantum yield, however, increased slightly upon conjugation, suggesting that the overall efficiency of the ZnTCPPc as a photosensitizer had improved. Physical mixing of the ZnTCPPc and the silica-coated gadolinium nanoparticles also showed an improvement in the singlet oxygen quantum yield and triplet lifetime, also showing an enhanced efficiency for the photosensitizer and therefore photocatalysis. ZnTCPPc (3) alone and the Pc-gadolinium oxide nanoparticle conjugate (4) were therefore electrospun into nanofibers to create a solid support. The fibers were characterized and their diameter sizes and composition was studied confirming the incorporation of the phthalocyanine and gadolinium oxide nanoparticle. Increased singlet oxygen generation resulted in increased Photodegradation of the environmental pollutant Orange G and the fibers were found to be more efficient as photocatalysts compared to the photosensitizer in solution. The nanomaterial may therefore be applied to the photodegradation of Orange G.
- Full Text:
- Date Issued: 2014
- Authors: Ledwaba, Mpho
- Date: 2014
- Language: English
- Type: text , Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10962/54610 , vital:26593
- Description: This work presents the syntheses, photophysical and photochemical characterization of zinc tetracarboxyphenoxy phthalocyanine (ZnTCPPc, 3) and its gadolinium oxide nanoparticle conjugate (4). By means of spectroscopic and microscopic characterization, the conjugation of the ZnTCPPc to the silica coated gadolinium oxide nanoparticles (Si-Gd2O3 NPs, 2) through an amide bond was confirmed. The thermal stability, morphology, nanoparticle sizes and their conjugates with the Pc were studied using ThermoGravimetric Analysis (TGA), Fourier Transform Infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and powder X-ray diffractometry (XRD). Conjugation of ZnTCPPc to the magnetic nanoparticles, proved to have a negligible effect on the photophysical parameters of the phthalocyanine, where a slight decrease in fluorescence and triplet quantum yields and lifetimes was observed. The singlet oxygen quantum yield, however, increased slightly upon conjugation, suggesting that the overall efficiency of the ZnTCPPc as a photosensitizer had improved. Physical mixing of the ZnTCPPc and the silica-coated gadolinium nanoparticles also showed an improvement in the singlet oxygen quantum yield and triplet lifetime, also showing an enhanced efficiency for the photosensitizer and therefore photocatalysis. ZnTCPPc (3) alone and the Pc-gadolinium oxide nanoparticle conjugate (4) were therefore electrospun into nanofibers to create a solid support. The fibers were characterized and their diameter sizes and composition was studied confirming the incorporation of the phthalocyanine and gadolinium oxide nanoparticle. Increased singlet oxygen generation resulted in increased Photodegradation of the environmental pollutant Orange G and the fibers were found to be more efficient as photocatalysts compared to the photosensitizer in solution. The nanomaterial may therefore be applied to the photodegradation of Orange G.
- Full Text:
- Date Issued: 2014
Characterization of electrodes modified by one pot or step by step electro-click reaction and axial ligation of iron tetracarboxyphthalocyanine
- Maringa, Audacity, Mashazi, Philani N, Nyokong, Tebello
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193892 , vital:45403 , xlink:href="https://doi.org/10.1016/j.electacta.2014.09.011"
- Description: The modification of the glassy carbon electrode (GCE) was carried out using two methods. The first method is simultaneous electropolymerization and electro-click followed by immersion into a solution of dimethyl formamide (DMF) containing FeTCPc. The second method is step by step whereby electropolymerization is carried out first followed by electro-click and then immersion into a DMF solution containing FeTCPc. From the electrochemical characterization, it was observed that the second route (step by step method) was the best as indicated by the ferricyanide studies (cyclic voltammetry and scanning electrochemical microscopy). In the electrooxidation of hydrazine, we obtained a potential of 0.26 V. Of interest were the detection limit of 6.4 μM and the catalytic rate constant of 2.1 × 109 cm3 mol−1 s−1. This shows that the sensor can be used for the electrooxidation of hydrazine.
- Full Text:
- Date Issued: 2014
- Authors: Maringa, Audacity , Mashazi, Philani N , Nyokong, Tebello
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/193892 , vital:45403 , xlink:href="https://doi.org/10.1016/j.electacta.2014.09.011"
- Description: The modification of the glassy carbon electrode (GCE) was carried out using two methods. The first method is simultaneous electropolymerization and electro-click followed by immersion into a solution of dimethyl formamide (DMF) containing FeTCPc. The second method is step by step whereby electropolymerization is carried out first followed by electro-click and then immersion into a DMF solution containing FeTCPc. From the electrochemical characterization, it was observed that the second route (step by step method) was the best as indicated by the ferricyanide studies (cyclic voltammetry and scanning electrochemical microscopy). In the electrooxidation of hydrazine, we obtained a potential of 0.26 V. Of interest were the detection limit of 6.4 μM and the catalytic rate constant of 2.1 × 109 cm3 mol−1 s−1. This shows that the sensor can be used for the electrooxidation of hydrazine.
- Full Text:
- Date Issued: 2014
Collection of urban tree products by households in poorer residential areas of three South African towns
- Kaoma, Humphrey, Shackleton, Charlie M
- Authors: Kaoma, Humphrey , Shackleton, Charlie M
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180980 , vital:43678 , xlink:href="https://doi.org/10.1016/j.ufug.2014.02.002"
- Description: The high rates of urban in-migration and poverty common in many developing country towns potentially increases the reliance of urban populations on the direct benefits provided by trees. Yet understanding of the extent of such use and the sources of these tree products is limited. Here we report on the extent of use of urban tree products by 450 households in the poorer areas of three towns along a rainfall gradient based on household questionnaires. We considered the proportion of households making use of each of several tree products and the collection or purchasing frequency which we disaggregated by source of the product, including trees in homesteads, urban spaces, edges of towns and via purchase from traders. Most households (91%) used firewood, which was most frequently collected from the urban fringe or purchased, although one-third at times also collected firewood from trees on their home plot. All households used fruits, most commonly sourced through purchase (98%), but nearly half of whom also supplemented by harvesting fruits from their home plot. Other products used included wood for building, fencing and utensils, herbal medicines, planting material and mulch. Collection of products from urban homestead trees was highest amongst households in the informal settlements and least in the more established townships. Residents of new low-cost housing areas made extensive use of urban tree products harvested in urban spaces because they had fewer homestead trees than residents of informal areas or townships. Overall, urban residents made use of a wide array of tangible products from trees which they sourced from a variety of places, including their homestead plot. This urges that planning agencies ensure that homestead plot sizes or other urban spaces that provide tree products are large enough to support the direct needs of poorer urban residents.
- Full Text:
- Date Issued: 2014
- Authors: Kaoma, Humphrey , Shackleton, Charlie M
- Date: 2014
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180980 , vital:43678 , xlink:href="https://doi.org/10.1016/j.ufug.2014.02.002"
- Description: The high rates of urban in-migration and poverty common in many developing country towns potentially increases the reliance of urban populations on the direct benefits provided by trees. Yet understanding of the extent of such use and the sources of these tree products is limited. Here we report on the extent of use of urban tree products by 450 households in the poorer areas of three towns along a rainfall gradient based on household questionnaires. We considered the proportion of households making use of each of several tree products and the collection or purchasing frequency which we disaggregated by source of the product, including trees in homesteads, urban spaces, edges of towns and via purchase from traders. Most households (91%) used firewood, which was most frequently collected from the urban fringe or purchased, although one-third at times also collected firewood from trees on their home plot. All households used fruits, most commonly sourced through purchase (98%), but nearly half of whom also supplemented by harvesting fruits from their home plot. Other products used included wood for building, fencing and utensils, herbal medicines, planting material and mulch. Collection of products from urban homestead trees was highest amongst households in the informal settlements and least in the more established townships. Residents of new low-cost housing areas made extensive use of urban tree products harvested in urban spaces because they had fewer homestead trees than residents of informal areas or townships. Overall, urban residents made use of a wide array of tangible products from trees which they sourced from a variety of places, including their homestead plot. This urges that planning agencies ensure that homestead plot sizes or other urban spaces that provide tree products are large enough to support the direct needs of poorer urban residents.
- Full Text:
- Date Issued: 2014
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 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