Synthesis, photophysical and nonlinear optical behavior of neodymium based trisphthalocyanine
- Sekhosana, Kutloana E, Amuhaya, Edith K, Khene, Samson M, Nyokong, Tebello
- Authors: Sekhosana, Kutloana E , Amuhaya, Edith K , Khene, Samson M , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241412 , vital:50937 , xlink:href="https://doi.org/10.1016/j.ica.2014.11.029"
- Description: Tris-{1(4),8(11),15(18),22(25)-tetra(4-tertbutylphenoxy) phthalocyaninato} dineodymium (III) was synthesised and its nonlinear optical and fluorescence behavior was studied. Low fluorescence quantum yield (ФF = 0.03) was obtained with a fluorescence lifetime τF = 4.31 ns for this complex. Nonlinear optical parameters for the complex were determined using the Z-scan technique and the values of Im[χ(3)] and γ were of the order of 10−10 and 10−28 esu, respectively. Square wave voltammetry revealed three reduction and two oxidation couples for the complex.
- Full Text:
- Authors: Sekhosana, Kutloana E , Amuhaya, Edith K , Khene, Samson M , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241412 , vital:50937 , xlink:href="https://doi.org/10.1016/j.ica.2014.11.029"
- Description: Tris-{1(4),8(11),15(18),22(25)-tetra(4-tertbutylphenoxy) phthalocyaninato} dineodymium (III) was synthesised and its nonlinear optical and fluorescence behavior was studied. Low fluorescence quantum yield (ФF = 0.03) was obtained with a fluorescence lifetime τF = 4.31 ns for this complex. Nonlinear optical parameters for the complex were determined using the Z-scan technique and the values of Im[χ(3)] and γ were of the order of 10−10 and 10−28 esu, respectively. Square wave voltammetry revealed three reduction and two oxidation couples for the complex.
- Full Text:
Synthesis, photophysics and photochemistry of phthalocyanine-ɛ-polylysine conjugates in the presence of metal nanoparticles against Staphylococcus aureus
- Nombona, Nolwazi, Antunes, Edith M, Chidawanyika, Wadzanai J U, Kleyi, Phumelele, Tshentu, Zenixole R, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Antunes, Edith M , Chidawanyika, Wadzanai J U , Kleyi, Phumelele , Tshentu, Zenixole R , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244439 , vital:51257 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: This work reports on the photodynamic activity of Zn phthalocyanine-ɛ-polylysine conjugates in the presence of gold and silver nanoparticles (NPs) towards the inactivation of Staphylococcus aureus (S. aureus). The conjugates showed high photoinactivation with ∼6% growth at a drug dose of 3 μM and fluence of 39.6 mW/cm2 for 10 min irradiation time in the presence of silver nanoparticles. The presence of silver nanoparticels from the minimal inhibition concentration (MIC50) studies showed remarkable growth inhibition for the tested conjugates even at low concentrations. The MIC50 was lowest for the conjugate of 3 with ɛ-polylysine at concentrations of less than 0.0058 μM in the presence of AgNPs. The lethal photosensitization of microorganisms has emerged as a promising treatment since bacteria have reduced possibilities of developing resistance to photodynamic therapy.
- Full Text:
- Authors: Nombona, Nolwazi , Antunes, Edith M , Chidawanyika, Wadzanai J U , Kleyi, Phumelele , Tshentu, Zenixole R , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244439 , vital:51257 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: This work reports on the photodynamic activity of Zn phthalocyanine-ɛ-polylysine conjugates in the presence of gold and silver nanoparticles (NPs) towards the inactivation of Staphylococcus aureus (S. aureus). The conjugates showed high photoinactivation with ∼6% growth at a drug dose of 3 μM and fluence of 39.6 mW/cm2 for 10 min irradiation time in the presence of silver nanoparticles. The presence of silver nanoparticels from the minimal inhibition concentration (MIC50) studies showed remarkable growth inhibition for the tested conjugates even at low concentrations. The MIC50 was lowest for the conjugate of 3 with ɛ-polylysine at concentrations of less than 0.0058 μM in the presence of AgNPs. The lethal photosensitization of microorganisms has emerged as a promising treatment since bacteria have reduced possibilities of developing resistance to photodynamic therapy.
- Full Text:
Synthetic analogues of the marine bisindole deoxytopsentin: potent selective inhibitors of MRSA pyruvate kinase
- Veale, Clinton G L, Zoraghi, Roya, Young, Ryan M, Morrison, James P, Pretheeban, Manoj, Lobb, Kevin A, Reiner, Neil E, Andersen, Raymond J, Davies-Coleman, Michael T
- Authors: Veale, Clinton G L , Zoraghi, Roya , Young, Ryan M , Morrison, James P , Pretheeban, Manoj , Lobb, Kevin A , Reiner, Neil E , Andersen, Raymond J , Davies-Coleman, Michael T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448045 , vital:74693 , xlink:href="https://doi.org/10.1021/np500755v"
- Description: As part of an ongoing study to elucidate the SAR of bisindole alkaloid inhibitors against the evolutionary conserved MRSA pyruvate kinase (PK), we present here the synthesis and biological activity of six dihalogenated analogues of the naturally occurring sponge metabolite deoxytopsentin, including the naturally occurring dibromodeoxytopsentin. The most active compounds displayed potent low nanomolar inhibitory activity against MRSA PK with concomitant significant selectivity for MRSA PK over human PK orthologues. Computational studies suggest that these potent MRSA PK inhibitors occupy a region of the small interface of the enzyme tetramer where amino acid sequence divergence from common human PK orthologues may contribute to the observed selectivity.
- Full Text:
- Authors: Veale, Clinton G L , Zoraghi, Roya , Young, Ryan M , Morrison, James P , Pretheeban, Manoj , Lobb, Kevin A , Reiner, Neil E , Andersen, Raymond J , Davies-Coleman, Michael T
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/448045 , vital:74693 , xlink:href="https://doi.org/10.1021/np500755v"
- Description: As part of an ongoing study to elucidate the SAR of bisindole alkaloid inhibitors against the evolutionary conserved MRSA pyruvate kinase (PK), we present here the synthesis and biological activity of six dihalogenated analogues of the naturally occurring sponge metabolite deoxytopsentin, including the naturally occurring dibromodeoxytopsentin. The most active compounds displayed potent low nanomolar inhibitory activity against MRSA PK with concomitant significant selectivity for MRSA PK over human PK orthologues. Computational studies suggest that these potent MRSA PK inhibitors occupy a region of the small interface of the enzyme tetramer where amino acid sequence divergence from common human PK orthologues may contribute to the observed selectivity.
- Full Text:
The benefits from and barriers to participation in civic environmental organisations in South Africa
- Higgins, Olivia, Shackleton, Charlie M
- Authors: Higgins, Olivia , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180813 , vital:43648 , xlink:href="https://doi.org/10.1007/s10531-015-0924-6"
- Description: With growing global public awareness of a wide range of conservation and environmental issues, environmental volunteerism is increasing. In order to attract and retain volunteers, it is useful to understand what benefits they hope for as well as the barriers that hinder their participation. Here we examine the benefits from and barriers to participation in 26 conservation and environmental civic organisations in South Africa, categorised by their primary mission as botanical, wildlife or green. Questionnaires were sent to volunteers on the mailing list of each civic organisation (and 66 responses received), supplemented with direct interviews with key staff and five focus group discussions. There were differences in the perception of benefits obtained and barriers experienced by volunteers between the three groups. Respondents from botanical and green civic organisations rated enjoyment of the task as the primary benefit, whereas the most common response amongst wildlife organisation volunteers was a higher level of life satisfaction. Lack of time was a major barrier across all groups, whilst lack of communication between organisers and volunteers was mentioned frequently by volunteers in wildlife and green organisations. The mean number of hours offered per volunteer was significantly higher amongst wildlife organisations than either botanical or green ones, but for all three, the value of volunteer contributions was, at several millions of rand annually, substantial. There was no relationship between the number of perceived benefits and the number of hours volunteered. This study indicates that motivations and barriers differ amongst volunteers, which is important to acknowledge in attracting and optimising the contributions of conservation and environmental volunteers.
- Full Text:
The benefits from and barriers to participation in civic environmental organisations in South Africa
- Authors: Higgins, Olivia , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180813 , vital:43648 , xlink:href="https://doi.org/10.1007/s10531-015-0924-6"
- Description: With growing global public awareness of a wide range of conservation and environmental issues, environmental volunteerism is increasing. In order to attract and retain volunteers, it is useful to understand what benefits they hope for as well as the barriers that hinder their participation. Here we examine the benefits from and barriers to participation in 26 conservation and environmental civic organisations in South Africa, categorised by their primary mission as botanical, wildlife or green. Questionnaires were sent to volunteers on the mailing list of each civic organisation (and 66 responses received), supplemented with direct interviews with key staff and five focus group discussions. There were differences in the perception of benefits obtained and barriers experienced by volunteers between the three groups. Respondents from botanical and green civic organisations rated enjoyment of the task as the primary benefit, whereas the most common response amongst wildlife organisation volunteers was a higher level of life satisfaction. Lack of time was a major barrier across all groups, whilst lack of communication between organisers and volunteers was mentioned frequently by volunteers in wildlife and green organisations. The mean number of hours offered per volunteer was significantly higher amongst wildlife organisations than either botanical or green ones, but for all three, the value of volunteer contributions was, at several millions of rand annually, substantial. There was no relationship between the number of perceived benefits and the number of hours volunteered. This study indicates that motivations and barriers differ amongst volunteers, which is important to acknowledge in attracting and optimising the contributions of conservation and environmental volunteers.
- Full Text:
The design and evaluation of targeted patient-centred health information to improve knowledge and behavioural outcomes in tuberculosis patients with limited literacy
- Authors: Patel, Sonal
- Date: 2015
- Subjects: Tuberculosis Patients , Health literacy , Patient education , Communication in medicine , Picture-writing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194071 , vital:45420 , DOI 10.21504/10962/194071
- Description: South Africa carries a significant TB burden as evidenced in the 2013 statistics which report 450 000 new active TB cases and 890 000 TB-related mortalities. For successful treatment outcomes, 90% adherence is necessary, but many patients prematurely discontinue treatment due to poor knowledge and understanding of their complex TB medicines. Patient education is pivotal in improving knowledge, health literacy and behavioural outcomes such as health information seeking, self-efficacy and adherence. In the under-resourced South African healthcare system, time and capacity to adequately counsel patients are limited. The value of written medicine information (WMI) to supplement the verbal information provided by healthcare professionals (HCPs) has been widely investigated but minimal South African research is available. Current WMI distributed in South Africa is mainly generated by pharmaceutical manufacturers and is complex, incomprehensible and undesirable to patients. TB-related WMI focuses mainly on the disease, with little information relating to TB medicines and their use. The overall aim of this project was to improve patient knowledge about their TB medicines through the use of a simple illustrated patient information leaflet (PIL). Objectives to achieve this aim included: investigation of the medicine information seeking behaviour (MISB) of long term patients attending public health sector facilities; the development and validation of a medicine literacy test (MLT) to identify patients with limited health literacy requiring additional support and counselling; the development and evaluation of a patient-centred illustrated PIL for first-line TB treatment; the assessment of self-efficacy and adherence using modified versions of the HIV Treatment Adherence Self-Efficacy Scale (HIV-ASES) and Morisky 8-item Medicine Adherence Scale (MMAS-8), respectively, and the investigation of the impact of the PIL on patient knowledge and these health-related behaviours. Six focus group discussions (FGDs) conducted in 34 isiXhosa-speaking patients with limited formal education taking long-term treatment explored themes related to information needs, information-seeking practices and awareness of and ability to utilize information sources. Codes were analysed and potential themes and subthemes were identified and refined. The findings of this study reflected a passive, disempowered patient due to both patient-related and systemic healthcare factors. Poor awareness of information sources, lack of health-related knowledge, stigma and lack of awareness of the importance of appropriate medicine-related knowledge contributed to a lack of information-seeking practice. Patients neither asked questions nor were encouraged to do so. All expressed an unmet need for information and a desire for receiving relevant, appropriate, written medicine-related information. Feedback from this phase of the study was used to inform the development of the targeted patientcentred PIL. A double-sided A4 PIL containing information about TB medicines was designed giving careful consideration to content, format and layout features. Twenty five pictograms were designed through a rigorous, iterative design process and were included in the PIL that was evaluated in a randomised control trial (RCT) conducted amongst 120 TB patients attending a high burden TB clinic in South Africa. Interviews were conducted in either isiXhosa or Afrikaans via a trained interpreter. Patients were randomly allocated to either a control (standard care) or an experimental group (standard care plus brief counselling using the PIL). Two interviews were conducted using a prepared questionnaire; one at baseline followed by a 4-week follow-up. Baseline data included demographics, medicine literacy test, health information sources, knowledge of TB medicines, self-reported adherence and self-efficacy. Data collected at the 4-week follow-up interview included TB knowledge, self-reported adherence, self-efficacy, opinion of TB medicine information and interpretation of pictograms. Data were analysed using t-test, correlations, chi-square and ANOVA tests at a 0.05 level of significance. The PIL was successful in improving patient knowledge of the disease, TB medicine-taking, side effects, drug-resistant TB and HIV and TB co-infection. At baseline, there was no significant difference in the overall mean percentage knowledge score between the control and experimental groups (p=0.074). At follow-up, the percentage knowledge score for the experimental group increased significantly from 59.0% to 84.6% (p<0.001) and showed a significantly higher score than the control group (p<0.001), displaying evidence of the impact of the PIL as a counselling tool on patient knowledge. The PIL generated a highly positive response in the experimental group who indicated that they had referred to the leaflet over the last month and that it had played an important role in improving their TB medicine-related knowledge. This was reflected in the experimental group knowledge score of greater than 80% for almost three quarters of the patients whereas only 14% in the control group achieved this score. Patients appreciated the inclusion of pictograms and strongly felt that they helped them to recall and understand the textual PIL content. The study found that patients want side effect information and, interestingly, did not perceive the presentation of side effects in pictorial form to constitute a risk factor for nonadherence. Use of the illustrated PIL (experimental group) resulted in a significant improvement in patient self-efficacy (p=0.002), but showed no effect on self-reported adherence (p=0.563). Neither self-efficacy nor adherence was influenced by gender, age or education. An education effect on knowledge was only observed in the control group at baseline. The newly developed MLT was shown to be a valid and reliable tool and a moderate, positive and significant correlation was noted between the MLT score and baseline TB medicine-related knowledge in both the control and experimental groups. As there is a paucity of studies investigating the influence of take-home written leaflets on TB medicine knowledge and on patient behaviour, this study represents a significant knowledge contribution. It is the first study to report the development and evaluation of a patient-centred PIL to address the dearth of available TB medicine information. The use of targeted user-friendly, illustrated information leaflets can be a valuable counselling aid to improve patient knowledge and self-efficacy, particularly among patients with limited literacy. However, careful consideration of the design and content, with input from the endusers at all stages of the process, will optimise its effectiveness. The proposed framework for the development and implementation of patient-centred health and medicines information in a developing country context presented in this thesis could be used as a theoretical basis for informing the development of effective information materials targeting other disease states. Local patients taking TB medicines identified nurses, WMI and media as their current sources of information but they expressed a strong desire to know more about their treatment. Targeted public health interventions that focus on medicine-taking information and behaviours and encourage patients to adopt a more active, questioning role in health consultations could improve health literacy and empower patients in their medicine-taking practices. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2015
- Full Text:
- Authors: Patel, Sonal
- Date: 2015
- Subjects: Tuberculosis Patients , Health literacy , Patient education , Communication in medicine , Picture-writing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10962/194071 , vital:45420 , DOI 10.21504/10962/194071
- Description: South Africa carries a significant TB burden as evidenced in the 2013 statistics which report 450 000 new active TB cases and 890 000 TB-related mortalities. For successful treatment outcomes, 90% adherence is necessary, but many patients prematurely discontinue treatment due to poor knowledge and understanding of their complex TB medicines. Patient education is pivotal in improving knowledge, health literacy and behavioural outcomes such as health information seeking, self-efficacy and adherence. In the under-resourced South African healthcare system, time and capacity to adequately counsel patients are limited. The value of written medicine information (WMI) to supplement the verbal information provided by healthcare professionals (HCPs) has been widely investigated but minimal South African research is available. Current WMI distributed in South Africa is mainly generated by pharmaceutical manufacturers and is complex, incomprehensible and undesirable to patients. TB-related WMI focuses mainly on the disease, with little information relating to TB medicines and their use. The overall aim of this project was to improve patient knowledge about their TB medicines through the use of a simple illustrated patient information leaflet (PIL). Objectives to achieve this aim included: investigation of the medicine information seeking behaviour (MISB) of long term patients attending public health sector facilities; the development and validation of a medicine literacy test (MLT) to identify patients with limited health literacy requiring additional support and counselling; the development and evaluation of a patient-centred illustrated PIL for first-line TB treatment; the assessment of self-efficacy and adherence using modified versions of the HIV Treatment Adherence Self-Efficacy Scale (HIV-ASES) and Morisky 8-item Medicine Adherence Scale (MMAS-8), respectively, and the investigation of the impact of the PIL on patient knowledge and these health-related behaviours. Six focus group discussions (FGDs) conducted in 34 isiXhosa-speaking patients with limited formal education taking long-term treatment explored themes related to information needs, information-seeking practices and awareness of and ability to utilize information sources. Codes were analysed and potential themes and subthemes were identified and refined. The findings of this study reflected a passive, disempowered patient due to both patient-related and systemic healthcare factors. Poor awareness of information sources, lack of health-related knowledge, stigma and lack of awareness of the importance of appropriate medicine-related knowledge contributed to a lack of information-seeking practice. Patients neither asked questions nor were encouraged to do so. All expressed an unmet need for information and a desire for receiving relevant, appropriate, written medicine-related information. Feedback from this phase of the study was used to inform the development of the targeted patientcentred PIL. A double-sided A4 PIL containing information about TB medicines was designed giving careful consideration to content, format and layout features. Twenty five pictograms were designed through a rigorous, iterative design process and were included in the PIL that was evaluated in a randomised control trial (RCT) conducted amongst 120 TB patients attending a high burden TB clinic in South Africa. Interviews were conducted in either isiXhosa or Afrikaans via a trained interpreter. Patients were randomly allocated to either a control (standard care) or an experimental group (standard care plus brief counselling using the PIL). Two interviews were conducted using a prepared questionnaire; one at baseline followed by a 4-week follow-up. Baseline data included demographics, medicine literacy test, health information sources, knowledge of TB medicines, self-reported adherence and self-efficacy. Data collected at the 4-week follow-up interview included TB knowledge, self-reported adherence, self-efficacy, opinion of TB medicine information and interpretation of pictograms. Data were analysed using t-test, correlations, chi-square and ANOVA tests at a 0.05 level of significance. The PIL was successful in improving patient knowledge of the disease, TB medicine-taking, side effects, drug-resistant TB and HIV and TB co-infection. At baseline, there was no significant difference in the overall mean percentage knowledge score between the control and experimental groups (p=0.074). At follow-up, the percentage knowledge score for the experimental group increased significantly from 59.0% to 84.6% (p<0.001) and showed a significantly higher score than the control group (p<0.001), displaying evidence of the impact of the PIL as a counselling tool on patient knowledge. The PIL generated a highly positive response in the experimental group who indicated that they had referred to the leaflet over the last month and that it had played an important role in improving their TB medicine-related knowledge. This was reflected in the experimental group knowledge score of greater than 80% for almost three quarters of the patients whereas only 14% in the control group achieved this score. Patients appreciated the inclusion of pictograms and strongly felt that they helped them to recall and understand the textual PIL content. The study found that patients want side effect information and, interestingly, did not perceive the presentation of side effects in pictorial form to constitute a risk factor for nonadherence. Use of the illustrated PIL (experimental group) resulted in a significant improvement in patient self-efficacy (p=0.002), but showed no effect on self-reported adherence (p=0.563). Neither self-efficacy nor adherence was influenced by gender, age or education. An education effect on knowledge was only observed in the control group at baseline. The newly developed MLT was shown to be a valid and reliable tool and a moderate, positive and significant correlation was noted between the MLT score and baseline TB medicine-related knowledge in both the control and experimental groups. As there is a paucity of studies investigating the influence of take-home written leaflets on TB medicine knowledge and on patient behaviour, this study represents a significant knowledge contribution. It is the first study to report the development and evaluation of a patient-centred PIL to address the dearth of available TB medicine information. The use of targeted user-friendly, illustrated information leaflets can be a valuable counselling aid to improve patient knowledge and self-efficacy, particularly among patients with limited literacy. However, careful consideration of the design and content, with input from the endusers at all stages of the process, will optimise its effectiveness. The proposed framework for the development and implementation of patient-centred health and medicines information in a developing country context presented in this thesis could be used as a theoretical basis for informing the development of effective information materials targeting other disease states. Local patients taking TB medicines identified nurses, WMI and media as their current sources of information but they expressed a strong desire to know more about their treatment. Targeted public health interventions that focus on medicine-taking information and behaviours and encourage patients to adopt a more active, questioning role in health consultations could improve health literacy and empower patients in their medicine-taking practices. , Thesis (PhD) -- Faculty of Pharmacy, Pharmacy, 2015
- Full Text:
The development of palladium (II)-specific amine-functionalized silica-based microparticles
- Fayemi, Omolola E, Ogunlaja, Adeniyi S, Antunes, Edith M, Nyokong, Tebello, Tshentu, Zenixole R
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241083 , vital:50903 , xlink:href="https://doi.org/10.1080/01496395.2014.978017"
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources.
- Full Text:
- Authors: Fayemi, Omolola E , Ogunlaja, Adeniyi S , Antunes, Edith M , Nyokong, Tebello , Tshentu, Zenixole R
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/241083 , vital:50903 , xlink:href="https://doi.org/10.1080/01496395.2014.978017"
- Description: The adsorption and separation of platinum(IV) and palladium(II) chlorido species ([PtCl6]2− and [PdCl4]2−) on silica-based microparticles functionalized with ammonium centers based on ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetriamine (TETA) and tris-(2-aminoethyl)amine (TAEA) were investigated. The functionalized sorbent materials were characterized using SEM, XPS, BET, and FTIR. The sorbents were used in the batch and column study for adsorption and selective separation of [PtCl62− and PdCl4]2−. The adsorption model for both [PtCl6]2− and [PdCl4]2− on the different sorbent materials fitted the Freundlich isotherm with R2 values > 0.99. The S-TETA sorbent material was palladium(II) specific. Pd(II) loaded on the silica column was recovered using 3% m/v thiourea solution as the eluting agent. Separation of platinum and palladium was achieved by selective stripping of [PtCl6]2− with 0.5 M of NaClO4 in 1.0 M HCl while Pd(II) was eluted with 0.5 M thiourea in 1.0 M HCl. The separation of palladium (Pd) from a mixture containing platinum (Pt), iridium (Ir), and rhodium (Rh) was successful on silica functionalized with triethylenetriamine (TETA) showing specificity for palladium(II) and a loading capacity of 0.27 mg/g. S-TETA showed potential for use in the recovery of palladium from platinum group metals such as from solutions of worn out automobile emission control catalytic convertors and other secondary sources.
- Full Text:
The development visions and attitudes towards urban forestry of officials responsible for greening in South African towns
- Gwedla, Nanamhla, Shackleton, Charlie M
- Authors: Gwedla, Nanamhla , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180856 , vital:43651 , xlink:href="https://doi.org/10.1016/j.landusepol.2014.07.004"
- Description: The planting and maintenance of trees in public areas of South African towns is the responsibility of local municipalities. Therefore, it is necessary to appreciate the visions and attitudes of municipal officials and decision-makers in charge of such activities for an understanding of the distribution and abundance of trees along streets and in urban green spaces. We hypothesised that the town size and relative wealth and current extent of trees in public places would influence the visions of such officials. We therefore conducted 24 semi-structured interviews with the officials responsible for urban tree planting in 24 towns in the Eastern Cape province, whilst also assessing the abundance of street trees via GIS counts. The density of street trees was variable, ranging from 0.5 to 9.5 trees/ha. There were significantly positive relationships between town size, relative wealth measures and street tree density. Several of the managers did not include environmental issues or trees in vision of the future for their town, although most did. There was no relationship between the managers’ visions for the future and attitudes and current street tree density. Most of the managers experienced several constraints in trying to implement their vision, notably a lack of funds for urban forestry, limited space for tree planting in low-cost housing developments, vandalism, and lack of skilled personnel.
- Full Text:
- Authors: Gwedla, Nanamhla , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180856 , vital:43651 , xlink:href="https://doi.org/10.1016/j.landusepol.2014.07.004"
- Description: The planting and maintenance of trees in public areas of South African towns is the responsibility of local municipalities. Therefore, it is necessary to appreciate the visions and attitudes of municipal officials and decision-makers in charge of such activities for an understanding of the distribution and abundance of trees along streets and in urban green spaces. We hypothesised that the town size and relative wealth and current extent of trees in public places would influence the visions of such officials. We therefore conducted 24 semi-structured interviews with the officials responsible for urban tree planting in 24 towns in the Eastern Cape province, whilst also assessing the abundance of street trees via GIS counts. The density of street trees was variable, ranging from 0.5 to 9.5 trees/ha. There were significantly positive relationships between town size, relative wealth measures and street tree density. Several of the managers did not include environmental issues or trees in vision of the future for their town, although most did. There was no relationship between the managers’ visions for the future and attitudes and current street tree density. Most of the managers experienced several constraints in trying to implement their vision, notably a lack of funds for urban forestry, limited space for tree planting in low-cost housing developments, vandalism, and lack of skilled personnel.
- Full Text:
The direct-use value of urban tree non-timber forest products to household income in poorer suburbs in South African towns
- Kaoma, Humphrey, Shackleton, Charlie M
- Authors: Kaoma, Humphrey , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180778 , vital:43645 , xlink:href="https://doi.org/10.1016/j.forpol.2015.08.005"
- Description: Valuation of the contribution of non-timber forest products (NTFPs) to household incomes has been well researched in the rural and remote areas of the developing world. In comparison, there has been little investigation of the contribution of NTFPs in urban areas and amongst the urban poor. This paper reports results from a survey of 450 households across three towns on the use and value of tree NTFPs collected by households in the poorer areas from their own homesteads, open spaces within towns and at the urban periphery. Collection (and purchase) of tree NTFPs was widespread, especially of firewood and fruits. The ratio collected from homesteads relative to other urban spaces differed between products and the amount required. Overall, approximately 20% of household income was derived from urban tree NTFPs. The highest contribution (33%) was amongst the poorest sectors represented by mostly recent migrants to towns who were living in informal settlements whilst trying to establish a foothold in the urban economy. In the formal housing areas the contribution was at least 14%, which has been overlooked by standard income surveys in urban areas.
- Full Text:
- Authors: Kaoma, Humphrey , Shackleton, Charlie M
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180778 , vital:43645 , xlink:href="https://doi.org/10.1016/j.forpol.2015.08.005"
- Description: Valuation of the contribution of non-timber forest products (NTFPs) to household incomes has been well researched in the rural and remote areas of the developing world. In comparison, there has been little investigation of the contribution of NTFPs in urban areas and amongst the urban poor. This paper reports results from a survey of 450 households across three towns on the use and value of tree NTFPs collected by households in the poorer areas from their own homesteads, open spaces within towns and at the urban periphery. Collection (and purchase) of tree NTFPs was widespread, especially of firewood and fruits. The ratio collected from homesteads relative to other urban spaces differed between products and the amount required. Overall, approximately 20% of household income was derived from urban tree NTFPs. The highest contribution (33%) was amongst the poorest sectors represented by mostly recent migrants to towns who were living in informal settlements whilst trying to establish a foothold in the urban economy. In the formal housing areas the contribution was at least 14%, which has been overlooked by standard income surveys in urban areas.
- Full Text:
The effect of ascorbic acid on the photophysical properties and photodynamic therapy activities of zinc phthalocyanine-single walled carbon nanotube conjugate on MCF-7 cancer cells
- Ogbodu, Racheal O, Nyokong, Tebello
- Authors: Ogbodu, Racheal O , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189066 , vital:44813 , xlink:href="https://doi.org/10.1016/j.saa.2015.06.063"
- Description: Zinc mono carboxy phenoxy phthalocyanine (1) was chemical modified with ascorbic acid via an ester bond to give ZnMCPPc-AA (2). Complexes 2 and 1 were coordinated to single walled carbon nanotubes via π–π interaction to give ZnMCPPc-AA-SWCNT (3) and ZnMCPPc-SWCNT (4) respectively. Complexes 2, 3 and 4 showed better photophysical properties: with improved triplet lifetimes and quantum yields, and singlet oxygen quantum yields when compared to 1 alone. The photodynamic therapy activities of complexes 1, 2, 3 and 4 were tested in vitro on MCF-7 breast cancer cells. Ascorbic acid suppresses the photodynamic therapy effect of 1, due to its ability to reduce oxidative DNA damage as a result of its potent reducing properties. The highest phototoxicity was observed for 4 which resulted in 77% decrease in cell viability, followed by 3 which resulted in 67% decrease in cell viability. This shows the importance of combination therapy, where the phthalocyanines are the photodynamic therapy agents and single walled carbon nanotubes are the photothermal therapy agents.
- Full Text:
- Authors: Ogbodu, Racheal O , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189066 , vital:44813 , xlink:href="https://doi.org/10.1016/j.saa.2015.06.063"
- Description: Zinc mono carboxy phenoxy phthalocyanine (1) was chemical modified with ascorbic acid via an ester bond to give ZnMCPPc-AA (2). Complexes 2 and 1 were coordinated to single walled carbon nanotubes via π–π interaction to give ZnMCPPc-AA-SWCNT (3) and ZnMCPPc-SWCNT (4) respectively. Complexes 2, 3 and 4 showed better photophysical properties: with improved triplet lifetimes and quantum yields, and singlet oxygen quantum yields when compared to 1 alone. The photodynamic therapy activities of complexes 1, 2, 3 and 4 were tested in vitro on MCF-7 breast cancer cells. Ascorbic acid suppresses the photodynamic therapy effect of 1, due to its ability to reduce oxidative DNA damage as a result of its potent reducing properties. The highest phototoxicity was observed for 4 which resulted in 77% decrease in cell viability, followed by 3 which resulted in 67% decrease in cell viability. This shows the importance of combination therapy, where the phthalocyanines are the photodynamic therapy agents and single walled carbon nanotubes are the photothermal therapy agents.
- Full Text:
The effect of long-distance transportation on the fitness of irradiated false codling Moth (Lepidoptera: Tortricidae) for use in a sterile insect release program
- Nepgen, Eugene S, Hill, Martin P, Moore, Sean D
- Authors: Nepgen, Eugene S , Hill, Martin P , Moore, Sean D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423835 , vital:72098 , xlink:href="https://doi.org/10.1093/jee/tov246"
- Description: The effect of cold immobilization and long-distance transport of irradiated Thaumatotibia leucotreta (Meyrick) on the flight ability of male (?) and female (/) moths, the longevity of male and female moths, and the realized fecundity of mating pairs CIM (chilled irradiated moths) / CIM?, CIM/ NIP (nonirradiated pupae) ?, NIP/ CIM?, and NIP/ NIP? was examined to improve application of the sterile insect technique (SIT). Adult moths treated with 150 Gy of gamma radiation were immobilized with cold temperature between 4 and 6C inside a polyurethane cooler box and transported for 12 h by road from Citrusdal, Western Cape Province, to Addo, Eastern Cape Province. Nonirradiated moths were transported as pupae inside a cardboard tray and removed by hand after which male and female pupae were separated and placed inside containers for eclosion. Male and female moths were individually placed inside petri dishes to determine longevity or paired with irradiated and nonirradiated counterparts to evaluate realized fecundity before incubation in 100% darkness at 25C and 75% relative humidity. Flight tests were conducted indoors at 25C by release of individual moths per hand. A significant decrease in flight ability and longevity of irradiated false codling moth was found after handling, cold immobilization, and transport, although critically, realized fecundity was not affected. Because of the impact of long-distance transport on quality of the released insects as well as the efficacy of SIT, comprehensive protocols for this critical step in the process need to be developed for a pestiferous insect with phytosanitary status such as false codling moth.
- Full Text:
- Authors: Nepgen, Eugene S , Hill, Martin P , Moore, Sean D
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/423835 , vital:72098 , xlink:href="https://doi.org/10.1093/jee/tov246"
- Description: The effect of cold immobilization and long-distance transport of irradiated Thaumatotibia leucotreta (Meyrick) on the flight ability of male (?) and female (/) moths, the longevity of male and female moths, and the realized fecundity of mating pairs CIM (chilled irradiated moths) / CIM?, CIM/ NIP (nonirradiated pupae) ?, NIP/ CIM?, and NIP/ NIP? was examined to improve application of the sterile insect technique (SIT). Adult moths treated with 150 Gy of gamma radiation were immobilized with cold temperature between 4 and 6C inside a polyurethane cooler box and transported for 12 h by road from Citrusdal, Western Cape Province, to Addo, Eastern Cape Province. Nonirradiated moths were transported as pupae inside a cardboard tray and removed by hand after which male and female pupae were separated and placed inside containers for eclosion. Male and female moths were individually placed inside petri dishes to determine longevity or paired with irradiated and nonirradiated counterparts to evaluate realized fecundity before incubation in 100% darkness at 25C and 75% relative humidity. Flight tests were conducted indoors at 25C by release of individual moths per hand. A significant decrease in flight ability and longevity of irradiated false codling moth was found after handling, cold immobilization, and transport, although critically, realized fecundity was not affected. Because of the impact of long-distance transport on quality of the released insects as well as the efficacy of SIT, comprehensive protocols for this critical step in the process need to be developed for a pestiferous insect with phytosanitary status such as false codling moth.
- Full Text:
The effects of gold coated and uncoated zinc oxide nanohexagons on the photophysicochemical properties of the low symmetry zinc phthalocyanine
- D'Souza, Sarah, Ogbodu, Rachael, Nyokong, Tebello
- Authors: D'Souza, Sarah , Ogbodu, Rachael , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189077 , vital:44814 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.06.088"
- Description: A new low symmetry, Zn phthalocyanine monosubstituted with diethylaminoethanethiol (mDEAET ZnPc) was synthesized and characterized. This work reports on its photophysical and photochemical properties of mDEAET ZnPc alone and when conjugated to gold coated and uncoated zinc oxide nanohexagons (ZnO NHXs). The photophysicochemical properties generally improved in the presence of the ZnO NHXs. These complexes were also tested for their photodynamic antimicrobial activity against Staphylococcus aureus (S. aureus). The Pc alone showed remarkable growth inhibition even at concentrations as low as 0.05 mg/mL. The conjugates showed a high photoinactivation of S. aureus after 30 min at a fluence of 90 mW cm−2 at a concentration of 0.05 mg/mL. The ZnPc-ZnO NHX conjugates produced the best antimicrobial results.
- Full Text:
- Authors: D'Souza, Sarah , Ogbodu, Rachael , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189077 , vital:44814 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.06.088"
- Description: A new low symmetry, Zn phthalocyanine monosubstituted with diethylaminoethanethiol (mDEAET ZnPc) was synthesized and characterized. This work reports on its photophysical and photochemical properties of mDEAET ZnPc alone and when conjugated to gold coated and uncoated zinc oxide nanohexagons (ZnO NHXs). The photophysicochemical properties generally improved in the presence of the ZnO NHXs. These complexes were also tested for their photodynamic antimicrobial activity against Staphylococcus aureus (S. aureus). The Pc alone showed remarkable growth inhibition even at concentrations as low as 0.05 mg/mL. The conjugates showed a high photoinactivation of S. aureus after 30 min at a fluence of 90 mW cm−2 at a concentration of 0.05 mg/mL. The ZnPc-ZnO NHX conjugates produced the best antimicrobial results.
- Full Text:
The Influence of Adaptive Co-management Interrelations on the Social Learning, Change and Transformation of the Pugu and Kazimzumbwi Community in Tanzania
- Authors: Ferdinand, Victoria
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387311 , vital:68224 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137668"
- Description: This study sought to identify signs of social learning, change and transformation resulting from adaptive co-management interrelations in terms of the project ‘Reduction of Emission from Deforestation and Forest Degradation’ (REDD) at the Pugu and Kazimzumbwi Forest Reserves (PKFR) community in Tanzania. The study therefore presents some enablers and constraints in respect of learning, agency formation, social change and transformation potentially influenced by the REDD. This is a qualitative case study that explored ‘learning’1 from living experiences of local people at the PKFR and from local mechanisms of the REDD project. Reflexive workshop interventions were used to validate the performance of local REDD practices against the adaptive co-management framework. Other data was obtained through interviews, focus-group discussion, the analysis of documents and direct observations. The study found that individual people may deepen their understanding of forestry issues through collaborative interrelations. Social learning in the PKFR community was potentially stimulated by people’s relational interactions, reflective thinking and anticipations, and questioning of past practices. Learning occurred subtly, and the learning process was not endured firmly enough to foster the complex learning dynamics necessary for transformational changes. As a result, most of the REDD-stimulated learning did not transform the practices desired in the project.
- Full Text:
- Authors: Ferdinand, Victoria
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/387311 , vital:68224 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137668"
- Description: This study sought to identify signs of social learning, change and transformation resulting from adaptive co-management interrelations in terms of the project ‘Reduction of Emission from Deforestation and Forest Degradation’ (REDD) at the Pugu and Kazimzumbwi Forest Reserves (PKFR) community in Tanzania. The study therefore presents some enablers and constraints in respect of learning, agency formation, social change and transformation potentially influenced by the REDD. This is a qualitative case study that explored ‘learning’1 from living experiences of local people at the PKFR and from local mechanisms of the REDD project. Reflexive workshop interventions were used to validate the performance of local REDD practices against the adaptive co-management framework. Other data was obtained through interviews, focus-group discussion, the analysis of documents and direct observations. The study found that individual people may deepen their understanding of forestry issues through collaborative interrelations. Social learning in the PKFR community was potentially stimulated by people’s relational interactions, reflective thinking and anticipations, and questioning of past practices. Learning occurred subtly, and the learning process was not endured firmly enough to foster the complex learning dynamics necessary for transformational changes. As a result, most of the REDD-stimulated learning did not transform the practices desired in the project.
- Full Text:
The influence of livelihood dependency, local ecological knowledge and market proximity on the ecological impacts of harvesting non-timber forest products
- Steele, Melita Z, Shackleton, Charlie M, Shaanker, Ramanan U, Ganeshaiah, Kotiganahalli N, Radloff, Sarah E
- Authors: Steele, Melita Z , Shackleton, Charlie M , Shaanker, Ramanan U , Ganeshaiah, Kotiganahalli N , Radloff, Sarah E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180908 , vital:43669 , xlink:href="https://doi.org/10.1016/j.forpol.2014.07.011"
- Description: It is well established that non-timber forest products make significant contributions to rural incomes throughout most of the developing world. NTFP use frequently raises concerns about the sustainability of, or ecological impacts associated with, NTFP harvesting, as well as local contextual factors which may limit or reduce the impacts. Here we test the conceptual model first advanced by Uma Shaanker et al. (2004) relating to the factors that may limit or exacerbate the ecological impacts associated with NTFP harvesting. These were the extent of local dependence on NTFPs, the degree of marketing and the level of local ecological knowledge. Data were collected via household questionnaires and ecological surveys of woody plants from eight villages throughout South Africa. We found no significant relationships between measures of ecological impact with local ecological knowledge or market proximity and engagement. There was a strong positive relationship between ecological impacts and NTFP dependency as indexed through mean annual direct-use value for NTFPs. This indicates that the higher the dependency and demand for NTFPs, the greater is the possibility of high impacts to the local environment. However, other contextual drivers not included in the original Uma Shaanker et al. (2004) model may also play a role, particularly the strength of local resource governance institutions.
- Full Text: false
- Authors: Steele, Melita Z , Shackleton, Charlie M , Shaanker, Ramanan U , Ganeshaiah, Kotiganahalli N , Radloff, Sarah E
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180908 , vital:43669 , xlink:href="https://doi.org/10.1016/j.forpol.2014.07.011"
- Description: It is well established that non-timber forest products make significant contributions to rural incomes throughout most of the developing world. NTFP use frequently raises concerns about the sustainability of, or ecological impacts associated with, NTFP harvesting, as well as local contextual factors which may limit or reduce the impacts. Here we test the conceptual model first advanced by Uma Shaanker et al. (2004) relating to the factors that may limit or exacerbate the ecological impacts associated with NTFP harvesting. These were the extent of local dependence on NTFPs, the degree of marketing and the level of local ecological knowledge. Data were collected via household questionnaires and ecological surveys of woody plants from eight villages throughout South Africa. We found no significant relationships between measures of ecological impact with local ecological knowledge or market proximity and engagement. There was a strong positive relationship between ecological impacts and NTFP dependency as indexed through mean annual direct-use value for NTFPs. This indicates that the higher the dependency and demand for NTFPs, the greater is the possibility of high impacts to the local environment. However, other contextual drivers not included in the original Uma Shaanker et al. (2004) model may also play a role, particularly the strength of local resource governance institutions.
- Full Text: false
The listening train: A collaborative, connective aesthetics approach to transgressive social learning
- Authors: McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/371023 , vital:66404 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137658"
- Description: This paper explores a personal iterative retrospective of a series of expansive social-learning processes that were collaboratively developed through practice-based enquiry across 17 South African towns/contexts. This reflexive narrative explores the development of a ‘Climate Train’, a mobile social-learning platform, that was conceived and created through a collaborative social movement of ‘cultural practitioners’ ranging from visual artists, poets, film-makers, theatre-makers, guerrilla-gardeners, musicians, facilitators, to educational researchers, among others, who created new ‘connective aesthetic’ social spaces for dialogue and exchange. Drawing from a variety of artistic genres, including but not limited to theatre and social sculpture (an expanded concept of public/participatory art), I reflect on the formative, foundational qualities of these approaches and share insights into social-learning praxis that emerged on the tracks. Of primary focus is the use of aesthetic praxis as a means that transforms how we engage with our inner capacities as well as how we develop our relational sensibilities. Key findings include the vital role of connective aesthetics in establishing imaginal thinking, moral intuition, empathy, participative parity, and emergence, and how these are important for transformation and establishing new capacities for ecological/global citizenship and collaborative intelligence.
- Full Text:
- Authors: McGarry, Dylan K
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/371023 , vital:66404 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/137658"
- Description: This paper explores a personal iterative retrospective of a series of expansive social-learning processes that were collaboratively developed through practice-based enquiry across 17 South African towns/contexts. This reflexive narrative explores the development of a ‘Climate Train’, a mobile social-learning platform, that was conceived and created through a collaborative social movement of ‘cultural practitioners’ ranging from visual artists, poets, film-makers, theatre-makers, guerrilla-gardeners, musicians, facilitators, to educational researchers, among others, who created new ‘connective aesthetic’ social spaces for dialogue and exchange. Drawing from a variety of artistic genres, including but not limited to theatre and social sculpture (an expanded concept of public/participatory art), I reflect on the formative, foundational qualities of these approaches and share insights into social-learning praxis that emerged on the tracks. Of primary focus is the use of aesthetic praxis as a means that transforms how we engage with our inner capacities as well as how we develop our relational sensibilities. Key findings include the vital role of connective aesthetics in establishing imaginal thinking, moral intuition, empathy, participative parity, and emergence, and how these are important for transformation and establishing new capacities for ecological/global citizenship and collaborative intelligence.
- Full Text:
The nocturnal larvae of a specialist folivore perform better on C hromolaena odorata leaves from a shaded environment
- Osariyekemwen O. Uyi, Costas Zachariades, Hill, Martin P, Conlong, Desmond
- Authors: Osariyekemwen O. Uyi , Costas Zachariades , Hill, Martin P , Conlong, Desmond
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424855 , vital:72189 , xlink:href="https://doi.org/10.1111/eea.12321"
- Description: Increasing evidence suggests that individuals of the same plant species occurring in different micro-habitats often show a degree of phenotypic and phytochemical variation. Consequently, insect herbivores associated with such plant species must deal with environment-mediated changes or variability in the traits of their host plants. In this study, we examined the effects of habitat condition (shadedvs. full-sun habitats) on plant traits and leaf characteristics of the invasive alien plant, Chromolaenaodorata (L.) King and Robinson (Asteraceae). In addition, the performance was evaluated in two generations of a specialist folivore, Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae), on leaves obtained from both shaded and full-sun habitats. The study was done in an area where the insect was introduced as a biological control agent. Leaves growing in shade were less tough, had higher water and nitrogen content, and lower total non-structural carbohydrate, compared with leaves growing in full sun. Plants growing in shade had longer leaves and were taller, but above-ground biomass was significantly reduced compared with plants growing in full sun. In both generations (parents and offspring), P. insulata developed faster and had larger pupal mass, increased growth rate, and higher fecundity when reared on shaded foliage compared with full-sun foliage. Although immature survival and adult longevity did not differ between habitats, Maw’s host suitability index indicated that shaded leaves were more suitable for the growth and reproduction of P. insulata. We suggest that the benefits obtained by P.insulata feeding on shaded foliage are associated with reduced toughness and enhanced nitrogen and water content of leaves. These results demonstrate that light-mediated changes in plant traits and leaf characteristics can affect insect folivore performance.
- Full Text:
- Authors: Osariyekemwen O. Uyi , Costas Zachariades , Hill, Martin P , Conlong, Desmond
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/424855 , vital:72189 , xlink:href="https://doi.org/10.1111/eea.12321"
- Description: Increasing evidence suggests that individuals of the same plant species occurring in different micro-habitats often show a degree of phenotypic and phytochemical variation. Consequently, insect herbivores associated with such plant species must deal with environment-mediated changes or variability in the traits of their host plants. In this study, we examined the effects of habitat condition (shadedvs. full-sun habitats) on plant traits and leaf characteristics of the invasive alien plant, Chromolaenaodorata (L.) King and Robinson (Asteraceae). In addition, the performance was evaluated in two generations of a specialist folivore, Pareuchaetes insulata (Walker) (Lepidoptera: Erebidae: Arctiinae), on leaves obtained from both shaded and full-sun habitats. The study was done in an area where the insect was introduced as a biological control agent. Leaves growing in shade were less tough, had higher water and nitrogen content, and lower total non-structural carbohydrate, compared with leaves growing in full sun. Plants growing in shade had longer leaves and were taller, but above-ground biomass was significantly reduced compared with plants growing in full sun. In both generations (parents and offspring), P. insulata developed faster and had larger pupal mass, increased growth rate, and higher fecundity when reared on shaded foliage compared with full-sun foliage. Although immature survival and adult longevity did not differ between habitats, Maw’s host suitability index indicated that shaded leaves were more suitable for the growth and reproduction of P. insulata. We suggest that the benefits obtained by P.insulata feeding on shaded foliage are associated with reduced toughness and enhanced nitrogen and water content of leaves. These results demonstrate that light-mediated changes in plant traits and leaf characteristics can affect insect folivore performance.
- Full Text:
The nonlinear absorption in new lanthanide double decker pyridine-based phthalocyanines in solution and thin films
- Sekhosana, Kutloana E, Nyokong, Tebello
- Authors: Sekhosana, Kutloana E , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189307 , vital:44836 , xlink:href="https://doi.org/10.1016/j.optmat.2015.05.022"
- Description: The optical behavior of bis-{2(3), 9(10), 16(17), 23(24)-(tetrapyridin-4-yloxy phthalocyaninato)} lanthanum (III) (2) and its ytterbium (3) counterpart in dimethyl sulfoxide are presented and compared to bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-4-yloxy phthalocyaninato)} ytterbium (III) (4). We report on the third-order susceptibility, second-order hyperpolarizability and the limiting threshold values. The nonlinear optical limiting threshold values of complexes 2, 3 and 4 showed improvement in the solid state (thin films), with complex 4 giving the best value at 0.033 J cm−2.
- Full Text:
- Authors: Sekhosana, Kutloana E , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189307 , vital:44836 , xlink:href="https://doi.org/10.1016/j.optmat.2015.05.022"
- Description: The optical behavior of bis-{2(3), 9(10), 16(17), 23(24)-(tetrapyridin-4-yloxy phthalocyaninato)} lanthanum (III) (2) and its ytterbium (3) counterpart in dimethyl sulfoxide are presented and compared to bis-{1(4), 8(11), 15(18), 22(25)-(tetrapyridin-4-yloxy phthalocyaninato)} ytterbium (III) (4). We report on the third-order susceptibility, second-order hyperpolarizability and the limiting threshold values. The nonlinear optical limiting threshold values of complexes 2, 3 and 4 showed improvement in the solid state (thin films), with complex 4 giving the best value at 0.033 J cm−2.
- Full Text:
The photophysical properties of multi-functional quantum dots-magnetic nanoparticles—indium octacarboxyphthalocyanine nanocomposite
- Tshangana, Charmaine, Nyokong, Tebello
- Authors: Tshangana, Charmaine , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189876 , vital:44942 , xlink:href="https://doi.org/10.1007/s10895-014-1497-6"
- Description: This work presents the development of a multifunctional hybrid nanoparticle made of L-glutathione capped quantum dots (GSH-CdSe@ZnS), amino functionalized Fe3O4 magnetic nanoparticles and indium octacarboxy phthalocyanine (ClInPc(COOH)8). In this work we investigate the photophysical properties of the individual components and the hybrid nanoparticle, in addition we study the energy transfer (Förster Resonance Energy Transfer (FRET)) in the complex. FRET efficiencies of ~48 % were obtained for energy transfer between the QDs (when alone or linked to MNPs). Both triplet yields and lifetimes of ClInPc(COOH)8 increase in the nanocomposite, with a decrease in fluorescence lifetime. The hybrid nanoparticle showed improved photophysical properties and as a result can be used in photodynamic therapy.
- Full Text:
- Authors: Tshangana, Charmaine , Nyokong, Tebello
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/189876 , vital:44942 , xlink:href="https://doi.org/10.1007/s10895-014-1497-6"
- Description: This work presents the development of a multifunctional hybrid nanoparticle made of L-glutathione capped quantum dots (GSH-CdSe@ZnS), amino functionalized Fe3O4 magnetic nanoparticles and indium octacarboxy phthalocyanine (ClInPc(COOH)8). In this work we investigate the photophysical properties of the individual components and the hybrid nanoparticle, in addition we study the energy transfer (Förster Resonance Energy Transfer (FRET)) in the complex. FRET efficiencies of ~48 % were obtained for energy transfer between the QDs (when alone or linked to MNPs). Both triplet yields and lifetimes of ClInPc(COOH)8 increase in the nanocomposite, with a decrease in fluorescence lifetime. The hybrid nanoparticle showed improved photophysical properties and as a result can be used in photodynamic therapy.
- Full Text:
The politics of interweaving performance cultures
- Authors: Krueger, Anton
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/225719 , vital:49252 , xlink:href="https://doi.org/10.1080/10137548.2015.1014170"
- Description: According to the former president of the International Federation of Theatre Research (IFTR), Brian Singleton, the study of ‘[i]nterculturalism as a practice and a theory gained currency with Richard Schechner’s anthropologically-inspired new discipline of performance studies’ (p. 79). Schechner’s new discipline led to the formation of the annual Performance Studies International (PSI) conferences, and earlier this year I attended the twentieth instalment in Shanghai, which was held under the rubric of ‘Tradition and the Avant-Garde’. One of the things which struck me was the extent to which the (relatively) newly economically empowered Chinese theatre makers were creating grand productions based on Western theatre traditions. For example, many of the presentations for delegates were based on Western texts (such as Hamlet, Miss Julie and even a play by Woody Allen). And yet these productions were performed in Mandarin, using purist Chinese forms, such as Beijing Opera. During the discussions there seemed to be an awkward defensiveness from some of the Chinese hosts who insisted they were not ‘copying’ Western theatre, but that they were using it to express a pure Chinese aesthetic. There were also other performances at the conference, such as a series of parables called Confucius Disciples, which told didactic tales with content very foreign to a Western audience. A visiting troupe from Bulgaria presented their own version of some of these parables, using a strongly East European aesthetic to convey a Chinese message. In this way, experiments with cultural forms and content were clearly foregrounded by the conference presentations.
- Full Text:
- Authors: Krueger, Anton
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/225719 , vital:49252 , xlink:href="https://doi.org/10.1080/10137548.2015.1014170"
- Description: According to the former president of the International Federation of Theatre Research (IFTR), Brian Singleton, the study of ‘[i]nterculturalism as a practice and a theory gained currency with Richard Schechner’s anthropologically-inspired new discipline of performance studies’ (p. 79). Schechner’s new discipline led to the formation of the annual Performance Studies International (PSI) conferences, and earlier this year I attended the twentieth instalment in Shanghai, which was held under the rubric of ‘Tradition and the Avant-Garde’. One of the things which struck me was the extent to which the (relatively) newly economically empowered Chinese theatre makers were creating grand productions based on Western theatre traditions. For example, many of the presentations for delegates were based on Western texts (such as Hamlet, Miss Julie and even a play by Woody Allen). And yet these productions were performed in Mandarin, using purist Chinese forms, such as Beijing Opera. During the discussions there seemed to be an awkward defensiveness from some of the Chinese hosts who insisted they were not ‘copying’ Western theatre, but that they were using it to express a pure Chinese aesthetic. There were also other performances at the conference, such as a series of parables called Confucius Disciples, which told didactic tales with content very foreign to a Western audience. A visiting troupe from Bulgaria presented their own version of some of these parables, using a strongly East European aesthetic to convey a Chinese message. In this way, experiments with cultural forms and content were clearly foregrounded by the conference presentations.
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The politics of philosophy in Africa
- Jones, Ward E, Metz, Thaddeus
- Authors: Jones, Ward E , Metz, Thaddeus
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275733 , vital:55074 , xlink:href="https://doi.org/10.1080/02580136.2015.1104797"
- Description: The background to the present discussion is the prevalence of political and personal criticisms in philosophical discussions about Africa. As philosophers in South Africa—both white and black—continue to philosophise seriously about Africa, responses to their work sometimes take the form of political and personal criticisms of, if not attacks on, the philosopher exploring and defending considerations about the African continent. One of us (TM) has been the target of such critiques in light of his work. Our aim in this conversation is not to diminish or deflect such critiques. On the contrary, our aim is to understand them, to make them as strong as possible, and to bring them into the cooler realm of philosophical discussion.
- Full Text:
- Authors: Jones, Ward E , Metz, Thaddeus
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/275733 , vital:55074 , xlink:href="https://doi.org/10.1080/02580136.2015.1104797"
- Description: The background to the present discussion is the prevalence of political and personal criticisms in philosophical discussions about Africa. As philosophers in South Africa—both white and black—continue to philosophise seriously about Africa, responses to their work sometimes take the form of political and personal criticisms of, if not attacks on, the philosopher exploring and defending considerations about the African continent. One of us (TM) has been the target of such critiques in light of his work. Our aim in this conversation is not to diminish or deflect such critiques. On the contrary, our aim is to understand them, to make them as strong as possible, and to bring them into the cooler realm of philosophical discussion.
- Full Text:
The prevalence of planning and management frameworks for trees and green spaces in urban areas of South Africa
- Chishaleshale, M, Shackleton, Charlie M, Gambiza, James, Gumbo, Davison
- Authors: Chishaleshale, M , Shackleton, Charlie M , Gambiza, James , Gumbo, Davison
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180884 , vital:43659 , xlink:href="https://doi.org/10.1016/j.ufug.2015.09.012"
- Description: Optimisation of the benefits from urban forestry and greening to urban dwellers and the environment rests on proactive and appropriate management planning, implementation and resourcing. Yet, lessons from the developed world show marked variability in development and adoption of urban tree and green space (UTGS) strategic plans and systematic monitoring and maintenance. Although financial and human resources for UTGS may be constrained in developing world contexts, there is no knowledge of the extent to which local authorities engage in appropriate and timely planning, management and monitoring. Here we examine the UTGS resourcing, planning, maintenance and integration across 28 local municipalities in the two poorest provinces in South Africa. It was revealed that most local municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7% of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32% had tree policies; 21% had tree planting schedules; 11% had tree maintenance schedules. Over 65% claimed to engage other stakeholders in tree planting, but much was passive receipt of trees for planting rather than citizen engagement around species, places and values. Generally, the prevalence of most planning and maintenance elements increased with increasing size of the municipality and the presence of personnel specifically for UTGS management. It is likely that the prevalence of planning and maintenance functions will increase with greater political support from municipal councillors which may also decrease funding challenges.
- Full Text:
- Authors: Chishaleshale, M , Shackleton, Charlie M , Gambiza, James , Gumbo, Davison
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/180884 , vital:43659 , xlink:href="https://doi.org/10.1016/j.ufug.2015.09.012"
- Description: Optimisation of the benefits from urban forestry and greening to urban dwellers and the environment rests on proactive and appropriate management planning, implementation and resourcing. Yet, lessons from the developed world show marked variability in development and adoption of urban tree and green space (UTGS) strategic plans and systematic monitoring and maintenance. Although financial and human resources for UTGS may be constrained in developing world contexts, there is no knowledge of the extent to which local authorities engage in appropriate and timely planning, management and monitoring. Here we examine the UTGS resourcing, planning, maintenance and integration across 28 local municipalities in the two poorest provinces in South Africa. It was revealed that most local municipalities were not managing their UTGS in a planned or systematic manner due to constraining factors such as insufficient funds, insufficient personnel, lack of equipment and lack of political support. Only 7% of the surveyed municipalities had an urban tree management plan and an estimate of the urban tree stock; 32% had tree policies; 21% had tree planting schedules; 11% had tree maintenance schedules. Over 65% claimed to engage other stakeholders in tree planting, but much was passive receipt of trees for planting rather than citizen engagement around species, places and values. Generally, the prevalence of most planning and maintenance elements increased with increasing size of the municipality and the presence of personnel specifically for UTGS management. It is likely that the prevalence of planning and maintenance functions will increase with greater political support from municipal councillors which may also decrease funding challenges.
- Full Text: