The effects of point of substitution on the formation of manganese phthalocyanine-based molecular materials
- Akinbulu, Isaac Adebayo, Khene, Samson, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Khene, Samson , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249103 , vital:51778 , xlink:href="https://doi.org/10.1016/j.tsf.2010.08.145"
- Description: Molecular films of manganese phthalocyanine (MnPc) complexes, tetra-substituted with 2-diethylaminoethanethio at the peripheral (Mn(OAc)-β-TDEAETPc, 1) and non-peripheral (Mn(OAc)-α-TDEAETPc, 2) positions were formed on glassy carbon electrode by electropolymerization and electrodeposition respectively. Atomic force microscopy images confirmed the presence of the films and revealed significant morphological differences. The films exhibited an electrocatalytic activity towards the oxidation of the insecticide, bendiocarb. Hydrodynamic technique, using rotating disc electrode voltammetry, was used to investigate the kinetics of electro-oxidation of the insecticide. Morphological differences of the films significantly influenced kinetic parameters. Values of Tafel slopes, obtained from Tafel plots, suggested that catalysis of bendiocarb occurred via outer sphere mechanism.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac Adebayo , Khene, Samson , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249103 , vital:51778 , xlink:href="https://doi.org/10.1016/j.tsf.2010.08.145"
- Description: Molecular films of manganese phthalocyanine (MnPc) complexes, tetra-substituted with 2-diethylaminoethanethio at the peripheral (Mn(OAc)-β-TDEAETPc, 1) and non-peripheral (Mn(OAc)-α-TDEAETPc, 2) positions were formed on glassy carbon electrode by electropolymerization and electrodeposition respectively. Atomic force microscopy images confirmed the presence of the films and revealed significant morphological differences. The films exhibited an electrocatalytic activity towards the oxidation of the insecticide, bendiocarb. Hydrodynamic technique, using rotating disc electrode voltammetry, was used to investigate the kinetics of electro-oxidation of the insecticide. Morphological differences of the films significantly influenced kinetic parameters. Values of Tafel slopes, obtained from Tafel plots, suggested that catalysis of bendiocarb occurred via outer sphere mechanism.
- Full Text:
- Date Issued: 2010
The effects of point of substitution on the electrochemical behavior of new manganese phthalocyanines, tetra-substituted with diethylaminoethanethiol
- Akinbulu, Isaac Adebayo, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249137 , vital:51781 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.003"
- Description: The syntheses and comparative studies of the spectral, voltammetry and spectroelectrochemical properties of new manganese phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral positions (complex 3b) are reported. Solution electrochemistry of complex 3a showed quasi-reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.07 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.78 V vs. Ag|AgCl) reductions, but no ring-based oxidation. However, complex 3b showed weak irreversible ring-oxidation signal (Ep = +0.86 vs. Ag|AgCl). Reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.04 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.68 V vs. Ag|AgCl) reductions were also observed for complex 3b. Spectroelectrochemistry was used to confirm these processes. Reduction process involving the metal (MnIIIPc−2/MnIIPc−2) was associated with the formation of manganese μ-oxo complex in complex 3a.
- Full Text:
- Date Issued: 2010
- Authors: Akinbulu, Isaac Adebayo , Nyokong, Tebello
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/249137 , vital:51781 , xlink:href="https://doi.org/10.1016/j.ica.2010.06.003"
- Description: The syntheses and comparative studies of the spectral, voltammetry and spectroelectrochemical properties of new manganese phthalocyanine complexes, tetra-substituted with diethylaminoethanethio at the peripheral (complex 3a) and non-peripheral positions (complex 3b) are reported. Solution electrochemistry of complex 3a showed quasi-reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.07 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.78 V vs. Ag|AgCl) reductions, but no ring-based oxidation. However, complex 3b showed weak irreversible ring-oxidation signal (Ep = +0.86 vs. Ag|AgCl). Reversible metal-based (MnIIIPc−2/MnIIPc−2, E1/2 = −0.04 V vs. Ag|AgCl) and ring-based (MnIIPc−2/MnIIPc−3, E1/2 = −0.68 V vs. Ag|AgCl) reductions were also observed for complex 3b. Spectroelectrochemistry was used to confirm these processes. Reduction process involving the metal (MnIIIPc−2/MnIIPc−2) was associated with the formation of manganese μ-oxo complex in complex 3a.
- Full Text:
- Date Issued: 2010
Formation, surface characterization, and electrocatalytic application of self-assembled monolayer films of tetra-substituted manganese, iron, and cobalt benzylthio phthalocyanine complexes
- Akinbulu, Isaac Adebayo, Ozoemena, Kenneth Iyke, Nyokong, Tebello
- Authors: Akinbulu, Isaac Adebayo , Ozoemena, Kenneth Iyke , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247163 , vital:51552 , xlink:href="https://doi.org/10.1007/s10008-010-1243-1"
- Description: Molecular thin films of manganese (SAM-2), iron (SAM-3), and cobalt (SAM-4) phthalocyanine complexes, non-peripherally tetra-substituted with benzylmercapto, were formed on polycrystalline gold disc electrode by self-assembly technique. Surface characteristics of the films were interrogated by cyclic voltammetry. Significant passivation of voltammetry processes associated with bare gold surface (gold oxidation and underpotential deposition of copper) confirmed formation of the films. Electrocatalytic property of the films was evidenced from better voltammetry responses (less positive oxidation potential and better current signal) of the insecticide, carbofuran, on these films, relative to that on bare gold electrode. In terms of less positive oxidation potential, the FePc derivative (3) gave the best response, while the best current signal was observed on SAM-2-modified gold electrode. The average heterogeneous rate constant, k, for the oxidation of carbofuran was 3.6 × 10−2 cm s−1 on the SAM film with the best current signal (SAM-2).
- Full Text:
- Date Issued: 2011
- Authors: Akinbulu, Isaac Adebayo , Ozoemena, Kenneth Iyke , Nyokong, Tebello
- Date: 2011
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/247163 , vital:51552 , xlink:href="https://doi.org/10.1007/s10008-010-1243-1"
- Description: Molecular thin films of manganese (SAM-2), iron (SAM-3), and cobalt (SAM-4) phthalocyanine complexes, non-peripherally tetra-substituted with benzylmercapto, were formed on polycrystalline gold disc electrode by self-assembly technique. Surface characteristics of the films were interrogated by cyclic voltammetry. Significant passivation of voltammetry processes associated with bare gold surface (gold oxidation and underpotential deposition of copper) confirmed formation of the films. Electrocatalytic property of the films was evidenced from better voltammetry responses (less positive oxidation potential and better current signal) of the insecticide, carbofuran, on these films, relative to that on bare gold electrode. In terms of less positive oxidation potential, the FePc derivative (3) gave the best response, while the best current signal was observed on SAM-2-modified gold electrode. The average heterogeneous rate constant, k, for the oxidation of carbofuran was 3.6 × 10−2 cm s−1 on the SAM film with the best current signal (SAM-2).
- Full Text:
- Date Issued: 2011
Photophysical and photochemical parameters of octakis (benzylthio) phthalocyaninato zinc, aluminium and tin
- Akpe, Victor, Brismar, Hjalmar, Nyokong, Tebello, Osadebe, Patience Ogoamak
- Authors: Akpe, Victor , Brismar, Hjalmar , Nyokong, Tebello , Osadebe, Patience Ogoamak
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248472 , vital:51689 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.08.033"
- Description: This paper addresses the synthesis of octa-substituted benzylthio metallophthalocyanines (OBTMPcs) that contain the central metal ions of Zn2+, Al3+ and Sn4+. The ground state absorption of ZnPc(SR)8 (OBTZnPc) along with the ZnPc derivatives, well documented in literature were used to study a new concept called the red shift index (RsI). The concept is based on the empirical values of RsI of the different complexes in solvent media. Unequivocally, parameters used in this paper show strong correlations that are consistent with the results obtained. For instance, RsI of the complexes tend to increase as the refractive index, nD, and solvent donor, DN, of solvent increases. Photodegradation (photobleaching) quantum yield, ϕd measurements of these compounds show that they are highly photostable, ϕd (0.03–0.33 × 10−5). The triplet quantum yield, ϕT (0.40–0.53) and the triplet lifetime, τT (610–810 μs) are within the typical range for metallophthalocyanines in DMSO. The photosensitisation efficiency, SΔ, is relatively high for all the molecules (0.74–0.90).
- Full Text:
- Date Issued: 2010
- Authors: Akpe, Victor , Brismar, Hjalmar , Nyokong, Tebello , Osadebe, Patience Ogoamak
- Date: 2010
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/248472 , vital:51689 , xlink:href="https://doi.org/10.1016/j.molstruc.2010.08.033"
- Description: This paper addresses the synthesis of octa-substituted benzylthio metallophthalocyanines (OBTMPcs) that contain the central metal ions of Zn2+, Al3+ and Sn4+. The ground state absorption of ZnPc(SR)8 (OBTZnPc) along with the ZnPc derivatives, well documented in literature were used to study a new concept called the red shift index (RsI). The concept is based on the empirical values of RsI of the different complexes in solvent media. Unequivocally, parameters used in this paper show strong correlations that are consistent with the results obtained. For instance, RsI of the complexes tend to increase as the refractive index, nD, and solvent donor, DN, of solvent increases. Photodegradation (photobleaching) quantum yield, ϕd measurements of these compounds show that they are highly photostable, ϕd (0.03–0.33 × 10−5). The triplet quantum yield, ϕT (0.40–0.53) and the triplet lifetime, τT (610–810 μs) are within the typical range for metallophthalocyanines in DMSO. The photosensitisation efficiency, SΔ, is relatively high for all the molecules (0.74–0.90).
- Full Text:
- Date Issued: 2010
Behavioural activities and chemical composition of fresh leaf essential oil of Plectranthus aegyptiacus from Southwest Nigeria in mice
- Akuegbe, Enimeya Dressman, Oyemitan, Idris Ajayi, Oyedeji, Opeoluwa, Ogunlowo, Ifeoluwa Isaac, Miya, Gugulethu Mathew, Oyedeji, Adebola
- Authors: Akuegbe, Enimeya Dressman , Oyemitan, Idris Ajayi , Oyedeji, Opeoluwa , Ogunlowo, Ifeoluwa Isaac , Miya, Gugulethu Mathew , Oyedeji, Adebola
- Date: 2021-6
- Subjects: Acute toxicity testing , Carvacrol , Essential oil , Behaviour modification , Plectranthus
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6506 , vital:46434 , ("https://doi.org/10.30574/gscbps.2021.14.2.0030")
- Description: This study determined the chemical composition of essential oil obtained from fresh leaf of Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) and determine its mechanism(s) of action in mice. The oil was hydro-distillated, and analyzed using gas chromatography-mass spectrometry. The effects of the oil (50, 100 and 150 mg/kg; i.p., n=6) on novelty-induced behavioural was assessed using open field test and head dipping on hole board. Probable mechanism(s) were evaluated using antagonists: flumazenil, naloxone and cyproheptadine at 2 mg/kg each, atropine and yohimbine at 5 mg/kg and 1 mg/kg respectively. The LD50 values obtained were 2154 and 490 mg/kg for oral and intraperitoneal routes respectively. The oil (50, 100 and150 mg/kg) significantly (p less 0.05, 0.01 and 0.01) inhibited all NIB and head dips. Flumazenil significantly (p less than 0.05) reversed the effect of the oil on NIB; atropine, naloxone and cyproheptadine significantly (p less than 0.01, 0.01 and 0.001) potentiated inhibitory effect on NIB respectively, while yohimbine showed no significantly effect. The analyzed oil showed 61 compounds, and the major compounds were carvacrol, germacrene-D, p-cymene and [1,1'-Bicyclopentyl]-2,2'-diol. The study concluded that the oil possessed central nervous system depressant activity, which could be mediated mainly through augmentation of GABAergic neurotransmission, while cholinergic-(muscarinic), adrenergic and serotonergic pathways may be involved.
- Full Text:
- Date Issued: 2021-6
- Authors: Akuegbe, Enimeya Dressman , Oyemitan, Idris Ajayi , Oyedeji, Opeoluwa , Ogunlowo, Ifeoluwa Isaac , Miya, Gugulethu Mathew , Oyedeji, Adebola
- Date: 2021-6
- Subjects: Acute toxicity testing , Carvacrol , Essential oil , Behaviour modification , Plectranthus
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/6506 , vital:46434 , ("https://doi.org/10.30574/gscbps.2021.14.2.0030")
- Description: This study determined the chemical composition of essential oil obtained from fresh leaf of Plectranthus aegyptiacus, and evaluated it for novelty-induced behavioural (NIB) and determine its mechanism(s) of action in mice. The oil was hydro-distillated, and analyzed using gas chromatography-mass spectrometry. The effects of the oil (50, 100 and 150 mg/kg; i.p., n=6) on novelty-induced behavioural was assessed using open field test and head dipping on hole board. Probable mechanism(s) were evaluated using antagonists: flumazenil, naloxone and cyproheptadine at 2 mg/kg each, atropine and yohimbine at 5 mg/kg and 1 mg/kg respectively. The LD50 values obtained were 2154 and 490 mg/kg for oral and intraperitoneal routes respectively. The oil (50, 100 and150 mg/kg) significantly (p less 0.05, 0.01 and 0.01) inhibited all NIB and head dips. Flumazenil significantly (p less than 0.05) reversed the effect of the oil on NIB; atropine, naloxone and cyproheptadine significantly (p less than 0.01, 0.01 and 0.001) potentiated inhibitory effect on NIB respectively, while yohimbine showed no significantly effect. The analyzed oil showed 61 compounds, and the major compounds were carvacrol, germacrene-D, p-cymene and [1,1'-Bicyclopentyl]-2,2'-diol. The study concluded that the oil possessed central nervous system depressant activity, which could be mediated mainly through augmentation of GABAergic neurotransmission, while cholinergic-(muscarinic), adrenergic and serotonergic pathways may be involved.
- Full Text:
- Date Issued: 2021-6
Extended use of grey water for irrigating home gardens in an arid environment
- Al-Ismaili, Abdulrahim M, Ahmed, Mushtaque, Al-Busaidi, Ahmed, Al-Adawi, Seif, Tandlich, Roman, Al-Amri, Mohammed
- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
- Full Text:
- Date Issued: 2017
- Authors: Al-Ismaili, Abdulrahim M , Ahmed, Mushtaque , Al-Busaidi, Ahmed , Al-Adawi, Seif , Tandlich, Roman , Al-Amri, Mohammed
- Date: 2017
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76048 , vital:30497 , https://doi.org/10.1007/s11356-017-8963-z
- Description: The use of treated grey water (GW) for home gardens, peri-urban agriculture and landscaping is becoming popular in many water stressed countries such as Oman. This study aims to investigate the treatment efficacy, health and chemical concerns, cost-benefits and maintenance protocol of a GW treatment system as well as the effect of irrigation with GW on crop yield. Therefore, a decentralized homemade GW treatment system was installed in a newly constructed house in Muscat, Oman and studied over a 2-year period. The treated GW was found to be suitable for irrigation as per Omani standards. GW when mixed with kitchen effluent substituted the use of nutrient supplements for plants and did not show any harmful chemical or biological contamination. The capital cost of the system was around US $980, and the annual operating cost was US $78 with annual income and savings from the system being around US $572 indicating a payback period of nearly 2 years. It was found that the system required simple but regular maintenance particularly cleaning of the top layer of the filter. It can be concluded from this study that such a GW system should be technically, economically and environmentally feasible in Oman. Also, wider acceptance by the general public to the idea of GW reuse will help in mitigating the water shortage problem of the country to some extent.
- Full Text:
- Date Issued: 2017
Prevalence and factors associated with suicidal ideation amongst college students in the Nelson Mandela Bay Municipality, South Africa
- Alabi, Adeyinka A, Oladimeji, Olawumi K, Adeniyi, Oladele Vincent
- Authors: Alabi, Adeyinka A , Oladimeji, Olawumi K , Adeniyi, Oladele Vincent
- Date: 2021
- Subjects: Suicidal behaviour Education (Higher) Students Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7235 , vital:53093 , xlink:href="https://doi.org/10.4102/safp.v63i1.5195"
- Description: Background: Suicidal behaviour amongst college students constitutes a significant social and public health problem globally. This study determined the prevalence and associated factors of suicidal ideation amongst students of higher education in the Nelson Mandela Bay Municipality (NMBM), South Africa. Methods: In this institution-based cross-sectional study, a multistage cluster sampling of 826 participants, drawn from a college in NMBM, was conducted from January to March 2020. Data were collected with a standardised self-administered questionnaire. Multivariable logistic regression analysis was used to identify the factors associated with suicidal ideation. Results: Participants’ ages ranged from 18 to 24 years, with a mean age of 20.49 years (standard deviation, 1.88 years). The lifetime prevalence of suicidal ideation and plans in the preceding 12 months were 24.5% and 9.6%, respectively. The odds of suicidal ideation were higher in students who experienced bullying (adjusted odds ratio [AOR], 1.89; 95% confidence interval [CI], 1.35–2.65), mental illness (AOR, 1.89; 95% CI, 1.35–2.65), a history of sexual assault (AOR, 2.50; 95% CI, 1.20–5.21) and experience of sexual assault by or to a close family member (AOR, 1.69; 95% CI, 1.01–2.82). Underlying chronic illness was associated with a twofold risk for suicidal ideation in both sexes. Conclusion: About a quarter of the students sampled at the college had experienced suicidal ideation and some had had suicidal plans in the preceding 12 months. Screening for the identified risk factors amongst the student population coupled with prompt interventions would mitigate the risk of suicide in the study population. Keywords: suicidal behaviour; suicidal plans; higher education; students; South Africa.
- Full Text:
- Date Issued: 2021
- Authors: Alabi, Adeyinka A , Oladimeji, Olawumi K , Adeniyi, Oladele Vincent
- Date: 2021
- Subjects: Suicidal behaviour Education (Higher) Students Article
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/11260/7235 , vital:53093 , xlink:href="https://doi.org/10.4102/safp.v63i1.5195"
- Description: Background: Suicidal behaviour amongst college students constitutes a significant social and public health problem globally. This study determined the prevalence and associated factors of suicidal ideation amongst students of higher education in the Nelson Mandela Bay Municipality (NMBM), South Africa. Methods: In this institution-based cross-sectional study, a multistage cluster sampling of 826 participants, drawn from a college in NMBM, was conducted from January to March 2020. Data were collected with a standardised self-administered questionnaire. Multivariable logistic regression analysis was used to identify the factors associated with suicidal ideation. Results: Participants’ ages ranged from 18 to 24 years, with a mean age of 20.49 years (standard deviation, 1.88 years). The lifetime prevalence of suicidal ideation and plans in the preceding 12 months were 24.5% and 9.6%, respectively. The odds of suicidal ideation were higher in students who experienced bullying (adjusted odds ratio [AOR], 1.89; 95% confidence interval [CI], 1.35–2.65), mental illness (AOR, 1.89; 95% CI, 1.35–2.65), a history of sexual assault (AOR, 2.50; 95% CI, 1.20–5.21) and experience of sexual assault by or to a close family member (AOR, 1.69; 95% CI, 1.01–2.82). Underlying chronic illness was associated with a twofold risk for suicidal ideation in both sexes. Conclusion: About a quarter of the students sampled at the college had experienced suicidal ideation and some had had suicidal plans in the preceding 12 months. Screening for the identified risk factors amongst the student population coupled with prompt interventions would mitigate the risk of suicide in the study population. Keywords: suicidal behaviour; suicidal plans; higher education; students; South Africa.
- Full Text:
- Date Issued: 2021
Optically stimulated luminescence and spectral emission features of radioluminescence and thermoluminescence of natural kunzite:
- Alatishe, M A, Ogundare, F O, Folley, Damilola E, Chithambo, Makaiko L, Chikwembani, S
- Authors: Alatishe, M A , Ogundare, F O , Folley, Damilola E , Chithambo, Makaiko L , Chikwembani, S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160478 , vital:40449 , https://doi.org/10.1016/j.radmeas.2020.106457
- Description: Features of luminescence optically stimulated from natural kunzite using 470 nm blue light are reported. Preparatory measurements of its X-ray excited radioluminescence and thermoluminescence show that the sample has two main bands centered at 360 nm and 600 nm. The optically stimulated luminescence discussed in this report was monitored in the UV region and is presumed to be the same 360 nm emission that appears in the radioluminescence and thermoluminescence spectra. The glow curve shows at least three peaks at 74, 202, 432 oC for heating at 1 oC and the third one is a composite of two. Only the first two peaks are deduced to contribute most of the optically stimulated luminescence.
- Full Text:
- Date Issued: 2020
- Authors: Alatishe, M A , Ogundare, F O , Folley, Damilola E , Chithambo, Makaiko L , Chikwembani, S
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/160478 , vital:40449 , https://doi.org/10.1016/j.radmeas.2020.106457
- Description: Features of luminescence optically stimulated from natural kunzite using 470 nm blue light are reported. Preparatory measurements of its X-ray excited radioluminescence and thermoluminescence show that the sample has two main bands centered at 360 nm and 600 nm. The optically stimulated luminescence discussed in this report was monitored in the UV region and is presumed to be the same 360 nm emission that appears in the radioluminescence and thermoluminescence spectra. The glow curve shows at least three peaks at 74, 202, 432 oC for heating at 1 oC and the third one is a composite of two. Only the first two peaks are deduced to contribute most of the optically stimulated luminescence.
- Full Text:
- Date Issued: 2020
Chemical archeoceanography:
- Albarede, Francis, Thibon, Fanny, Blichert-Toft, Janne, Tsikos, Harilaos
- Authors: Albarede, Francis , Thibon, Fanny , Blichert-Toft, Janne , Tsikos, Harilaos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149065 , vital:38801 , https://doi.org/10.1016/j.chemgeo.2020.119625
- Description: Elemental fluxes to the ocean are expected to increase with the surface area of continental exposure to weathering and atmospheric PCO2. The record of phosphorus in sediments, which has no notable source within the ocean, and the radiogenic strontium isotopes in Archean carbonates indicate that, prior to the Great Oxidation Event (GOE), subaerial expanses represented only about 20% of the modern continental surface area, i.e. 7% of the surface of the Earth. Because these simple first-order observations, in contrast to the low oxygen content of the pre-GOE atmosphere, have so far received only little attention in the appraisal of the marine chemistry of the early Earth, a reassessment of the chemistry of the pre-GOE ocean is warranted. Here we discuss some of the geochemical cycles of the Archean world, including protons, alkalinity, electrons, and other electrolytes, and attempt to build a first conceptual framework for Chemical Archeoceanography.
- Full Text:
- Date Issued: 2020
- Authors: Albarede, Francis , Thibon, Fanny , Blichert-Toft, Janne , Tsikos, Harilaos
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/149065 , vital:38801 , https://doi.org/10.1016/j.chemgeo.2020.119625
- Description: Elemental fluxes to the ocean are expected to increase with the surface area of continental exposure to weathering and atmospheric PCO2. The record of phosphorus in sediments, which has no notable source within the ocean, and the radiogenic strontium isotopes in Archean carbonates indicate that, prior to the Great Oxidation Event (GOE), subaerial expanses represented only about 20% of the modern continental surface area, i.e. 7% of the surface of the Earth. Because these simple first-order observations, in contrast to the low oxygen content of the pre-GOE atmosphere, have so far received only little attention in the appraisal of the marine chemistry of the early Earth, a reassessment of the chemistry of the pre-GOE ocean is warranted. Here we discuss some of the geochemical cycles of the Archean world, including protons, alkalinity, electrons, and other electrolytes, and attempt to build a first conceptual framework for Chemical Archeoceanography.
- Full Text:
- Date Issued: 2020
Keeping food on the table: responses and changing coastal fisheries in Solomon Islands
- Albert, Simon, Aswani, Shankar, Fisher, Paul L, Albert, Joelle
- Authors: Albert, Simon , Aswani, Shankar , Fisher, Paul L , Albert, Joelle
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70593 , vital:29678 , https://doi.org/10.1371/journal.pone.0130800
- Description: Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/ or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
- Full Text:
- Date Issued: 2015
- Authors: Albert, Simon , Aswani, Shankar , Fisher, Paul L , Albert, Joelle
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70593 , vital:29678 , https://doi.org/10.1371/journal.pone.0130800
- Description: Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/ or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
- Full Text:
- Date Issued: 2015
Food on the Table: Human Responses and Changing Coastal Fisheries in Solomon Islands
- Albert, Simon, Aswani, Shankar, Fisher, Paul L, Albert, Joelle
- Authors: Albert, Simon , Aswani, Shankar , Fisher, Paul L , Albert, Joelle
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/421887 , vital:71893 , xlink:href="https://doi.org/10.1371/journal.pone.0130800"
- Description: Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
- Full Text:
- Date Issued: 2015
- Authors: Albert, Simon , Aswani, Shankar , Fisher, Paul L , Albert, Joelle
- Date: 2015
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/421887 , vital:71893 , xlink:href="https://doi.org/10.1371/journal.pone.0130800"
- Description: Globally the majority of commercial fisheries have experienced dramatic declines in stock and catch. Likewise, projections for many subsistence fisheries in the tropics indicate a dramatic decline is looming in the coming decades. In the Pacific Islands coastal fisheries provide basic subsistence needs for millions of people. A decline in fish catch would therefore have profound impacts on the health and livelihoods of these coastal communities. Given the decrease in local catch rates reported for many coastal communities in the Pacific, it is important to understand if fishers have responded to ecological change (either by expanding their fishing range and/or increasing their fishing effort), and if so, to evaluate the costs or benefits of these responses. We compare data from fish catches in 1995 and 2011 from a rural coastal community in Solomon Islands to examine the potentially changing coastal reef fishery at these time points. In particular we found changes in preferred fishing locations, fishing methodology and catch composition between these data sets. The results indicate that despite changes in catch rates (catch per unit effort) between data collected in 2011 and 16 years previously, the study community was able to increase gross catches through visiting fishing sites further away, diversifying fishing methods and targeting pelagic species through trolling. Such insight into local-scale responses to changing resources and/or fisheries development will help scientists and policy makers throughout the Pacific region in managing the region’s fisheries in the future.
- Full Text:
- Date Issued: 2015
Cost-effective methods for accurate determination of sea level rise vulnerability: A Solomon Islands example
- Albert, Simon, Abernethy, Kirsten, Gibbes, Badin, Grinham, Alistair, Tooler, Nixon, Aswani, Shankar
- Authors: Albert, Simon , Abernethy, Kirsten , Gibbes, Badin , Grinham, Alistair , Tooler, Nixon , Aswani, Shankar
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422708 , vital:71971 , xlink:href="https://doi.org/10.1175/WCAS-D-13-00010.1"
- Description: For millions of people living along the coastal fringe, sea level rise is perhaps the greatest threat to livelihoods over the coming century. With the refinement and downscaling of global climate models and increasing availability of airborne-lidar-based inundation models, it is possible to predict and quantify these threats with reasonable accuracy where such information is available. For less developed countries, especially small island states, access to high-resolution digital elevation models (DEMs) derived from lidar is limited. The only freely available DEMs that could be used for inundation modeling by these nations are those based on data from the Shuttle Radar Topography Mission (SRTM). These data, with a horizontal resolution of ≈90 m and a vertical accuracy of ±5–10 m, are generally unsuitable for local-scale planning and adaption projects. To address this disparity, low-cost ground-based techniques were tested and applied to accurately determine coastal topography in the Solomon Islands. This method had a significantly improved vertical accuracy (±2 cm) and was readily learned by local community members, who were able to independently map and determine the vulnerability of their costal community to inundation from sea level rise. For areas where lidar is not economically viable, this method is intended to provide an important balance of cost, simplicity, accuracy, and local participation that can assist remote coastal communities with coastal planning decisions. The method can enhance local capacity and arguably promotes more meaningful local engagement in sea level rise planning and adaptation activities.
- Full Text:
- Date Issued: 2013
- Authors: Albert, Simon , Abernethy, Kirsten , Gibbes, Badin , Grinham, Alistair , Tooler, Nixon , Aswani, Shankar
- Date: 2013
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/422708 , vital:71971 , xlink:href="https://doi.org/10.1175/WCAS-D-13-00010.1"
- Description: For millions of people living along the coastal fringe, sea level rise is perhaps the greatest threat to livelihoods over the coming century. With the refinement and downscaling of global climate models and increasing availability of airborne-lidar-based inundation models, it is possible to predict and quantify these threats with reasonable accuracy where such information is available. For less developed countries, especially small island states, access to high-resolution digital elevation models (DEMs) derived from lidar is limited. The only freely available DEMs that could be used for inundation modeling by these nations are those based on data from the Shuttle Radar Topography Mission (SRTM). These data, with a horizontal resolution of ≈90 m and a vertical accuracy of ±5–10 m, are generally unsuitable for local-scale planning and adaption projects. To address this disparity, low-cost ground-based techniques were tested and applied to accurately determine coastal topography in the Solomon Islands. This method had a significantly improved vertical accuracy (±2 cm) and was readily learned by local community members, who were able to independently map and determine the vulnerability of their costal community to inundation from sea level rise. For areas where lidar is not economically viable, this method is intended to provide an important balance of cost, simplicity, accuracy, and local participation that can assist remote coastal communities with coastal planning decisions. The method can enhance local capacity and arguably promotes more meaningful local engagement in sea level rise planning and adaptation activities.
- Full Text:
- Date Issued: 2013
The influence of citrus orchard age on the ecology of entomopathogenic fungi and nematodes
- Albertyn ,Sonnica, Moore, Sean D, Marsberg, Tamryn, Coombes, Candice A, Hill, Martin P
- Authors: Albertyn ,Sonnica , Moore, Sean D , Marsberg, Tamryn , Coombes, Candice A , Hill, Martin P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417545 , vital:71462 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: A three-year survey of the ecology of entomopathogenic nematodes (EPN) and entomopathogenic fungi (EPF) was undertaken on soils from citrus orchards of different ages to determine the influence of orchard age on the ecology of entomopathogenic fungi and nematodes. The influence of mulch and irrigation method on the occurrence of EPN and EPF was also determined. Most of the isolates recovered (n = 810) were Beauveria sp. (87.88% of all isolates), followed by Metarhizium sp. (11.87% of all isolates). Only 0.24% of soil samples collected during this study tested positive for EPN. All EPN isolates recovered were Heterorhabditis bacteriophora. No significant differences in EPF occurrence were recorded between orchards under drip and micro-sprinkler irrigation. EPF occurrence was significantly lower (P = 0.016) in orchards covered by mulch (31.85% ± 2.07% occurrence) than in orchards with no covering (38.57% ± 1.57% occurrence). EPF occurrence of 40.33 ± 2.13% was highest in non-bearing orchards, followed by mature orchards (nine years or older) (36.76 ± 2.05% of samples) with the lowest EPF occurrence of 25.30 ± 2.02% reported in juvenile orchards (four to eight years old). Juvenile orchards sustain significantly less EPF than mature and non-bearing orchards because of the combined negative impact of less favourable environmental conditions (lower shade density) and fungicide applications.
- Full Text:
- Date Issued: 2020
- Authors: Albertyn ,Sonnica , Moore, Sean D , Marsberg, Tamryn , Coombes, Candice A , Hill, Martin P
- Date: 2020
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417545 , vital:71462 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: A three-year survey of the ecology of entomopathogenic nematodes (EPN) and entomopathogenic fungi (EPF) was undertaken on soils from citrus orchards of different ages to determine the influence of orchard age on the ecology of entomopathogenic fungi and nematodes. The influence of mulch and irrigation method on the occurrence of EPN and EPF was also determined. Most of the isolates recovered (n = 810) were Beauveria sp. (87.88% of all isolates), followed by Metarhizium sp. (11.87% of all isolates). Only 0.24% of soil samples collected during this study tested positive for EPN. All EPN isolates recovered were Heterorhabditis bacteriophora. No significant differences in EPF occurrence were recorded between orchards under drip and micro-sprinkler irrigation. EPF occurrence was significantly lower (P = 0.016) in orchards covered by mulch (31.85% ± 2.07% occurrence) than in orchards with no covering (38.57% ± 1.57% occurrence). EPF occurrence of 40.33 ± 2.13% was highest in non-bearing orchards, followed by mature orchards (nine years or older) (36.76 ± 2.05% of samples) with the lowest EPF occurrence of 25.30 ± 2.02% reported in juvenile orchards (four to eight years old). Juvenile orchards sustain significantly less EPF than mature and non-bearing orchards because of the combined negative impact of less favourable environmental conditions (lower shade density) and fungicide applications.
- Full Text:
- Date Issued: 2020
The influence of citrus orchard age on the ecology of entomopathogenic fungi and nematodes
- Albertyn, Sonnica, Moore, Sean D, Marsberg, Tamryn, Coombes, Candice A, Hill, Martin P
- Authors: Albertyn, Sonnica , Moore, Sean D , Marsberg, Tamryn , Coombes, Candice A , Hill, Martin P
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417790 , vital:71486 , xlink:href="https://doi.org/10.1080/09583157.2020.1830949"
- Description: A three-year survey of the ecology of entomopathogenic nematodes (EPN) and entomopathogenic fungi (EPF) was undertaken on soils from citrus orchards of different ages to determine the influence of orchard age on the ecology of entomopathogenic fungi and nematodes. The influence of mulch and irrigation method on the occurrence of EPN and EPF was also determined. Most of the isolates recovered (n = 810) were Beauveria sp. (87.88% of all isolates), followed by Metarhizium sp. (11.87% of all isolates). Only 0.24% of soil samples collected during this study tested positive for EPN. All EPN isolates recovered were Heterorhabditis bacteriophora. No significant differences in EPF occurrence were recorded between orchards under drip and micro-sprinkler irrigation. EPF occurrence was significantly lower (P = 0.016) in orchards covered by mulch (31.85% ± 2.07% occurrence) than in orchards with no covering (38.57% ± 1.57% occurrence). EPF occurrence of 40.33 ± 2.13% was highest in non-bearing orchards, followed by mature orchards (nine years or older) (36.76 ± 2.05% of samples) with the lowest EPF occurrence of 25.30 ± 2.02% reported in juvenile orchards (four to eight years old). Juvenile orchards sustain significantly less EPF than mature and non-bearing orchards because of the combined negative impact of less favourable environmental conditions (lower shade density) and fungicide applications.
- Full Text:
- Date Issued: 2021
- Authors: Albertyn, Sonnica , Moore, Sean D , Marsberg, Tamryn , Coombes, Candice A , Hill, Martin P
- Date: 2021
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/417790 , vital:71486 , xlink:href="https://doi.org/10.1080/09583157.2020.1830949"
- Description: A three-year survey of the ecology of entomopathogenic nematodes (EPN) and entomopathogenic fungi (EPF) was undertaken on soils from citrus orchards of different ages to determine the influence of orchard age on the ecology of entomopathogenic fungi and nematodes. The influence of mulch and irrigation method on the occurrence of EPN and EPF was also determined. Most of the isolates recovered (n = 810) were Beauveria sp. (87.88% of all isolates), followed by Metarhizium sp. (11.87% of all isolates). Only 0.24% of soil samples collected during this study tested positive for EPN. All EPN isolates recovered were Heterorhabditis bacteriophora. No significant differences in EPF occurrence were recorded between orchards under drip and micro-sprinkler irrigation. EPF occurrence was significantly lower (P = 0.016) in orchards covered by mulch (31.85% ± 2.07% occurrence) than in orchards with no covering (38.57% ± 1.57% occurrence). EPF occurrence of 40.33 ± 2.13% was highest in non-bearing orchards, followed by mature orchards (nine years or older) (36.76 ± 2.05% of samples) with the lowest EPF occurrence of 25.30 ± 2.02% reported in juvenile orchards (four to eight years old). Juvenile orchards sustain significantly less EPF than mature and non-bearing orchards because of the combined negative impact of less favourable environmental conditions (lower shade density) and fungicide applications.
- Full Text:
- Date Issued: 2021
The privacy paradox applies to IoT devices too: a Saudi Arabian study
- Aleisa, Noura, Renaud, Karen, Bongiovanni, Ivano
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150252 , vital:38953 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses. Our Saudi Arabian participants, despite expressing high levels of privacy concerns, generally chose not to respond to this evidence with preventative action.
- Full Text:
- Date Issued: 2020
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/150252 , vital:38953 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses. Our Saudi Arabian participants, despite expressing high levels of privacy concerns, generally chose not to respond to this evidence with preventative action.
- Full Text:
- Date Issued: 2020
The Privacy Paradox applies to IoT devices too: a Saudi Arabian study
- Aleisa, Noura, Renaud, Karen, Bongiovanni, Ivano
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158350 , vital:40176 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses.
- Full Text:
- Date Issued: 2020
- Authors: Aleisa, Noura , Renaud, Karen , Bongiovanni, Ivano
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158350 , vital:40176 , https://doi.org/10.1016/j.cose.2020.101897
- Description: The “privacy paradox” is the term used to describe the disconnect between self-reported privacy value attributions and actions actually taken to protect and preserve personal privacy. This phenomenon has been investigated in a number of domains and we extend the body of research with an investigation in the IoT domain. We presented participants with evidence of a specific IoT device’s (smart plug) privacy violations and then measured changes in privacy concerns and trust, as well as uptake of a range of behavioural responses.
- Full Text:
- Date Issued: 2020
The landscape of childhood: play and place as tools to understanding children’s enviromental use and perceptions
- Alexander, Jamie K, Cocks, Michelle L, Shackleton, Charlie M
- Authors: Alexander, Jamie K , Cocks, Michelle L , Shackleton, Charlie M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141165 , vital:37949 , DOI: 10.1007/s10745-015-9755-z
- Description: Research has shown that children are the greatest users of natural areas and that childhood experiences strongly shape adults’ environmental values. This project was designed to ascertain children’s environmental uses and perceptions in two rural villages in the Eastern Cape, South Africa, utilising children’s use of the environment for play and their sense of place as key focus areas. Several factors influenced children’s environmental use, including safety fears, increased consumption of western media and environmental restrictions imposed by the state, revealing how South Africa’s high level of violence against women and children contributes to gendered environmental use and knowledge, and bringing about concern for children’s cultural identity in an increasingly westernised world.
- Full Text:
- Date Issued: 2015
- Authors: Alexander, Jamie K , Cocks, Michelle L , Shackleton, Charlie M
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141165 , vital:37949 , DOI: 10.1007/s10745-015-9755-z
- Description: Research has shown that children are the greatest users of natural areas and that childhood experiences strongly shape adults’ environmental values. This project was designed to ascertain children’s environmental uses and perceptions in two rural villages in the Eastern Cape, South Africa, utilising children’s use of the environment for play and their sense of place as key focus areas. Several factors influenced children’s environmental use, including safety fears, increased consumption of western media and environmental restrictions imposed by the state, revealing how South Africa’s high level of violence against women and children contributes to gendered environmental use and knowledge, and bringing about concern for children’s cultural identity in an increasingly westernised world.
- Full Text:
- Date Issued: 2015
A feminist perspective on autonomism and commoning, with reference to Zimbabwe
- Alexander, Tarryn, Helliker, Kirk D
- Authors: Alexander, Tarryn , Helliker, Kirk D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71374 , vital:29838 , https://doi.org/10.1080/02589001.2016.1235353
- Description: This article engages with the autonomist Marxism of John Holloway from a feminist standpoint. The positions developed by this feminist critique are used to shed new light on the land occupations in contemporary Zimbabwe. Though sympathetic to his work, we argue that Holloway does not sufficiently address gender identity with specific reference to social reproduction and women. The notions of the commons and the process of commoning are consistent with Holloway’s autonomist framework and its complementarities to Silvia Federici’s Marxist feminist lens on the commons is highlighted. Against a tendency within autonomist and commoning theories, we argue for a pronounced identitarian politics as grounded in localised struggles undertaken by women as women. We privilege the significance of women asserting and revaluing their identities as part of a possible project of transformation. For us, struggling against and beyond what exists is invariably rooted in struggles within what exists (including identities).
- Full Text: false
- Date Issued: 2016
- Authors: Alexander, Tarryn , Helliker, Kirk D
- Date: 2016
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71374 , vital:29838 , https://doi.org/10.1080/02589001.2016.1235353
- Description: This article engages with the autonomist Marxism of John Holloway from a feminist standpoint. The positions developed by this feminist critique are used to shed new light on the land occupations in contemporary Zimbabwe. Though sympathetic to his work, we argue that Holloway does not sufficiently address gender identity with specific reference to social reproduction and women. The notions of the commons and the process of commoning are consistent with Holloway’s autonomist framework and its complementarities to Silvia Federici’s Marxist feminist lens on the commons is highlighted. Against a tendency within autonomist and commoning theories, we argue for a pronounced identitarian politics as grounded in localised struggles undertaken by women as women. We privilege the significance of women asserting and revaluing their identities as part of a possible project of transformation. For us, struggling against and beyond what exists is invariably rooted in struggles within what exists (including identities).
- Full Text: false
- Date Issued: 2016
The palladacycle, AJ-5, exhibits anti-tumour and anti-cancer stem cell activity in breast cancer cells:
- Aliwaini, Saeb, Peres, Jade, Kröger, Wendy L, Blanckenberg, Angelique, de la Mare, Jo-Anne, Edkins, Adrienne L, Mapolie, Selwyn, Prince, Sharon
- Authors: Aliwaini, Saeb , Peres, Jade , Kröger, Wendy L , Blanckenberg, Angelique , de la Mare, Jo-Anne , Edkins, Adrienne L , Mapolie, Selwyn , Prince, Sharon
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164874 , vital:41180 , DOI: 10.1016/j.canlet.2014.11.027
- Description: Breast cancer is the most common malignancy amongst women worldwide but despite enormous efforts to address this problem, there is still limited success with most of the current therapeutic strategies. The current study describes the anti-cancer activity of a binuclear palladacycle complex (AJ-5) in oestrogen receptor positive (MCF7) and oestrogen receptor negative (MDA-MB-231) breast cancer cells as well as human breast cancer stem cells. AJ-5 is shown to induce DNA double strand breaks leading to intrinsic and extrinsic apoptosis and autophagy cell death pathways which are mediated by the p38 MAP kinase. This study provides evidence that AJ-5 is potentially an effective compound in the treatment of breast cancer.
- Full Text:
- Date Issued: 2015
- Authors: Aliwaini, Saeb , Peres, Jade , Kröger, Wendy L , Blanckenberg, Angelique , de la Mare, Jo-Anne , Edkins, Adrienne L , Mapolie, Selwyn , Prince, Sharon
- Date: 2015
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/164874 , vital:41180 , DOI: 10.1016/j.canlet.2014.11.027
- Description: Breast cancer is the most common malignancy amongst women worldwide but despite enormous efforts to address this problem, there is still limited success with most of the current therapeutic strategies. The current study describes the anti-cancer activity of a binuclear palladacycle complex (AJ-5) in oestrogen receptor positive (MCF7) and oestrogen receptor negative (MDA-MB-231) breast cancer cells as well as human breast cancer stem cells. AJ-5 is shown to induce DNA double strand breaks leading to intrinsic and extrinsic apoptosis and autophagy cell death pathways which are mediated by the p38 MAP kinase. This study provides evidence that AJ-5 is potentially an effective compound in the treatment of breast cancer.
- Full Text:
- Date Issued: 2015
Determining the unbinding events and conserved motions associated with the pyrazinamide release due to resistance mutations of Mycobacterium tuberculosis pyrazinamidase:
- Amamuddy, Olivier S, Musyoka, Thommas M, Boateng, Rita A, Zabo, Sophakama, Tastan Bishop, Özlem
- Authors: Amamuddy, Olivier S , Musyoka, Thommas M , Boateng, Rita A , Zabo, Sophakama , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148869 , vital:38781 , https://doi.org/10.1016/j.csbj.2020.05.0099
- Description: Pyrazinamide (PZA) is the only first-line antitubercular drug active against latent Mycobacterium tuberculosis (Mtb). It is activated to pyrazinoic acid by the pncA-encoded pyrazinamidase enzyme (PZase). Despite the emergence of PZA drug resistance, the underlying mechanisms of resistance remain unclear. This study investigated part of these mechanisms by modelling a PZA-bound wild type and 82 mutant PZase structures before applying molecular dynamics (MD) with an accurate Fe2+ cofactor coordination geometry.
- Full Text:
- Date Issued: 2020
- Authors: Amamuddy, Olivier S , Musyoka, Thommas M , Boateng, Rita A , Zabo, Sophakama , Tastan Bishop, Özlem
- Date: 2020
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/148869 , vital:38781 , https://doi.org/10.1016/j.csbj.2020.05.0099
- Description: Pyrazinamide (PZA) is the only first-line antitubercular drug active against latent Mycobacterium tuberculosis (Mtb). It is activated to pyrazinoic acid by the pncA-encoded pyrazinamidase enzyme (PZase). Despite the emergence of PZA drug resistance, the underlying mechanisms of resistance remain unclear. This study investigated part of these mechanisms by modelling a PZA-bound wild type and 82 mutant PZase structures before applying molecular dynamics (MD) with an accurate Fe2+ cofactor coordination geometry.
- Full Text:
- Date Issued: 2020