A comparative study on the sensitive detection of hydroxyl radical using thiol-capped CdTe and CdTe/ZnS quantum dots
- Adegoke, Oluwasesan, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242778 , vital:51077 , xlink:href="https://doi.org/10.1007/s10895-012-1089-2"
- Description: Four types of water-soluble luminescent quantum dots (QDs) whose surface was functionlaized with thioglycolic acid (TGA), 3-mercaptopropionic acid (MPA), or glutathione (GSH), were investigated for the sensitive and selective detection of hydroxyl radical (●OH) in aqueous media. It was found that the type of capping agent and QD influenced the sensitivity of the probe. The order of sensitivity of the probe was: GSH-CdTe@ZnS > MPA-CdTe@ZnS > TGA-CdTe > MPA-CdTe QDs. Under the optimum conditions, a limit of detection as low as 8.5 × 10-8 M was obtained using GSH-CdTe@ZnS. The effects of foreign reactive oxygen species and the Fenton reactants and products as possible interferences on the proposed probe were negligible for CdTe@ZnS QDs. Besides, experimental results indicated that CdTe@ZnS QDs were more attractive for the selective recognition of ●OH than CdTe QDs. The mechanistic reaction pathway between the QDs and ●OH is proposed.
- Full Text:
- Date Issued: 2012
- Authors: Adegoke, Oluwasesan , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/242778 , vital:51077 , xlink:href="https://doi.org/10.1007/s10895-012-1089-2"
- Description: Four types of water-soluble luminescent quantum dots (QDs) whose surface was functionlaized with thioglycolic acid (TGA), 3-mercaptopropionic acid (MPA), or glutathione (GSH), were investigated for the sensitive and selective detection of hydroxyl radical (●OH) in aqueous media. It was found that the type of capping agent and QD influenced the sensitivity of the probe. The order of sensitivity of the probe was: GSH-CdTe@ZnS > MPA-CdTe@ZnS > TGA-CdTe > MPA-CdTe QDs. Under the optimum conditions, a limit of detection as low as 8.5 × 10-8 M was obtained using GSH-CdTe@ZnS. The effects of foreign reactive oxygen species and the Fenton reactants and products as possible interferences on the proposed probe were negligible for CdTe@ZnS QDs. Besides, experimental results indicated that CdTe@ZnS QDs were more attractive for the selective recognition of ●OH than CdTe QDs. The mechanistic reaction pathway between the QDs and ●OH is proposed.
- Full Text:
- Date Issued: 2012
Interaction of CdTe quantum dots with 2, 2-diphenyl-1-picrylhydrazyl free radical
- Adegoke, Oluwasesan, Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245751 , vital:51402 , xlink:href="https://doi.org/10.1007/s10895-011-1012-2"
- Description: The interaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH●) free radical with thiol-capped CdTe quantum dots (QDs) has been studied by UV–vis spectroscopy, steady state and time resolved fluorescence measurements. Addition of DPPH● radical to CdTe QDs resulted in fluorescence quenching. The interaction occurs through static quenching as this was confirmed by fluorescence lifetime measurements. Time course absorption studies indicates that DPPH● may be reduced by interaction with QDs to the substituted hydrazine form (2,2-diphenyl-1-picrylhydrazine) DPPH-H. The mechanism of fluorescence quenching of CdTe QDs by DPPH● is proposed.
- Full Text:
- Date Issued: 2012
- Authors: Adegoke, Oluwasesan , Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/245751 , vital:51402 , xlink:href="https://doi.org/10.1007/s10895-011-1012-2"
- Description: The interaction of 2,2-diphenyl-1-picrylhydrazyl (DPPH●) free radical with thiol-capped CdTe quantum dots (QDs) has been studied by UV–vis spectroscopy, steady state and time resolved fluorescence measurements. Addition of DPPH● radical to CdTe QDs resulted in fluorescence quenching. The interaction occurs through static quenching as this was confirmed by fluorescence lifetime measurements. Time course absorption studies indicates that DPPH● may be reduced by interaction with QDs to the substituted hydrazine form (2,2-diphenyl-1-picrylhydrazine) DPPH-H. The mechanism of fluorescence quenching of CdTe QDs by DPPH● is proposed.
- Full Text:
- Date Issued: 2012
CdTe quantum dots functionalized with 4-amino-2, 2, 6, 6-tetramethylpiperidine-N-oxide as luminescent nanoprobe for the sensitive recognition of bromide ion
- Adegoke, Oluwasesan, Hosten, Eric C, McCleland, Cedric, Nyokong, Tebello
- Authors: Adegoke, Oluwasesan , Hosten, Eric C , McCleland, Cedric , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244393 , vital:51253 , xlink:href="https://doi.org/10.1016/j.aca.2012.01.040"
- Description: A novel bromide ion-selective modified nanoprobe sensor based on 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT)-functionalized CdTe quantum dots (QDs-4AT) has been developed. Fluorescence quenching of the QDs by 4AT was observed. The functionalized QDs-4AT nanoprobe allowed a highly sensitive determination of bromide ion via analyte-induced change in the photoluminescence (fluorescence recovery) of the modified QDs. A detection limit of 0.6 nM of bromide ion was obtained, while the interfering effect of other inorganic cations and anions was investigated to examine the selectivity of the nanoprobe. The linear range was between 0.01 and 0.13 μM. Combined fluorescence lifetime and electron paramagnetic resonance measurements confirmed electron transfer processes between bromide ion and QDs-4AT.
- Full Text:
- Date Issued: 2012
- Authors: Adegoke, Oluwasesan , Hosten, Eric C , McCleland, Cedric , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/244393 , vital:51253 , xlink:href="https://doi.org/10.1016/j.aca.2012.01.040"
- Description: A novel bromide ion-selective modified nanoprobe sensor based on 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT)-functionalized CdTe quantum dots (QDs-4AT) has been developed. Fluorescence quenching of the QDs by 4AT was observed. The functionalized QDs-4AT nanoprobe allowed a highly sensitive determination of bromide ion via analyte-induced change in the photoluminescence (fluorescence recovery) of the modified QDs. A detection limit of 0.6 nM of bromide ion was obtained, while the interfering effect of other inorganic cations and anions was investigated to examine the selectivity of the nanoprobe. The linear range was between 0.01 and 0.13 μM. Combined fluorescence lifetime and electron paramagnetic resonance measurements confirmed electron transfer processes between bromide ion and QDs-4AT.
- Full Text:
- Date Issued: 2012
A highly selective and sensitive pyridylazo-2-naphthol-poly (acrylic acid) functionalized electrospun nanofiber fluorescence “turn-off” chemosensory system for Ni 2+
- Adewuyi, Sheriff, Ondigo, Dezzline A, Zugle, Ruphino, Tshentu, Zenixole R, Nyokong, Tebello, Torto, Nelson
- Authors: Adewuyi, Sheriff , Ondigo, Dezzline A , Zugle, Ruphino , Tshentu, Zenixole R , Nyokong, Tebello , Torto, Nelson
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/246012 , vital:51428 , xlink:href="https://doi.org/10.1039/C2AY25182E"
- Description: A fluorescent nanofiber probe for the determination of Ni2+ was developed via the electrospinning of a covalently functionalized pyridylazo-2-naphthol-poly(acrylic acid) polymer. Fluorescent nanofibers with diameters in the range 230–800 nm were produced with uniformly dispersed fluorophores. The excitation and emission fluorescence were at wavelengths 479 and 557 nm respectively, thereby exhibiting a good Stokes' shift. This Ni2+ probe that employs fluorescence quenching in a solid receptor–fluorophore system exhibited a good correlation between the fluorescence intensity and nickel concentration up to 1.0 μg mL−1 based on the Stern–Volmer mechanism. The probe achieved a detection limit (3δ/S) of 0.07 ng mL−1 and a precision, calculated as a relative standard deviation (RSD) of more than 4% (n = 8). The concentration of Ni2+ in a certified reference material (SEP-3) was found to be 0.8986 μg mL−1, which is significantly comparable with the certified value of 0.8980 μg mL−1. The accuracy of the determinations, expressed as a relative error between the certified and the observed values of certified reference groundwater was ≤0.1%. The versatility of the nanofiber probe was demonstrated by affording simple, rapid and selective detection of Ni2+ in the presence of other competing metal ions by direct analysis, without employing any further sample handling steps.
- Full Text:
- Date Issued: 2012
- Authors: Adewuyi, Sheriff , Ondigo, Dezzline A , Zugle, Ruphino , Tshentu, Zenixole R , Nyokong, Tebello , Torto, Nelson
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/246012 , vital:51428 , xlink:href="https://doi.org/10.1039/C2AY25182E"
- Description: A fluorescent nanofiber probe for the determination of Ni2+ was developed via the electrospinning of a covalently functionalized pyridylazo-2-naphthol-poly(acrylic acid) polymer. Fluorescent nanofibers with diameters in the range 230–800 nm were produced with uniformly dispersed fluorophores. The excitation and emission fluorescence were at wavelengths 479 and 557 nm respectively, thereby exhibiting a good Stokes' shift. This Ni2+ probe that employs fluorescence quenching in a solid receptor–fluorophore system exhibited a good correlation between the fluorescence intensity and nickel concentration up to 1.0 μg mL−1 based on the Stern–Volmer mechanism. The probe achieved a detection limit (3δ/S) of 0.07 ng mL−1 and a precision, calculated as a relative standard deviation (RSD) of more than 4% (n = 8). The concentration of Ni2+ in a certified reference material (SEP-3) was found to be 0.8986 μg mL−1, which is significantly comparable with the certified value of 0.8980 μg mL−1. The accuracy of the determinations, expressed as a relative error between the certified and the observed values of certified reference groundwater was ≤0.1%. The versatility of the nanofiber probe was demonstrated by affording simple, rapid and selective detection of Ni2+ in the presence of other competing metal ions by direct analysis, without employing any further sample handling steps.
- Full Text:
- Date Issued: 2012
Optimisation of expression of a rice (Oryza sativa L.cv Nipponbare) plant natriuretic peptide (OsPNP-B) and its functional characterisation
- Authors: Affun, Ogheneochuko Janet
- Date: 2012
- Subjects: Rice , Plant hormones , Water-electrolyte imbalances
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24354 , vital:62644
- Description: Maintenance of water and solute homeostasis is a key requirement for living systems, and in vertebrates, homeostasis is in part achieved by natriuretic peptides (NP), a family of peptide hormones. A related family of peptide hormones have also been found in the plant kingdom. Plant natriuretic peptides (PNP) are a novel class of plant proteins with two closely related homologous genes (AtPNP-A and AtPNP-B) identified in the model plant Arabidopsis thaliana. AtPNP-A has been extensively studied and evidence obtained points to a role in plant water homeostasis. No research has been conducted on the function of PNP-B proteins. In this study, we focus on the bioinformatic analysis of the PNP-B gene in various plants, as well investigating whether PNP-B plays a role in water homeostasis in rice plants exposed to drought stress. Basic local alignment search tool (BLAST) queries of the ―The Gene Index‖, EST and available plant genome databases revealed the presence of the PNP-B mRNA in rice, oil seed rape, oak, leafy spurge, poplar, sugarcane, pepper, cotton, apple and maize. All the identified genome sequences contained a predicted intron/insert, which was not present in the related mRNA sequences. However, RT-PCR analysis revealed the presence of the 101 bp insert in the 976 bp amplified rice PNP-B (OsPNP-B) cDNA and therefore expression was optimized for the protein encoded by only the exon2 sequence as this contained the predicted active site region of PNP-B. OsPNP-B was shown to be translated to a protein of 14 kDa with a sequence similarity to AtPNP-B (54percent), AtPNP-A (37percent) and CjBAp12 (55percent), suggesting two possible functions for PNP-B viz water homeostasis and/or pathogenesis defence. To determine whether PNP-B is involved in water homeostasis, total protein extracted from 4 weeks old (4 leaves stage) rice plants subjected to drought treatment for a period of 24, 48, 72, 120, 168 and 240hrs were resolved by 17percent SDS-PAGE and analysed by western blot analysis. The PNP-B protein was found to be down-regulated during drought stress, implying that PNP-B may play a role in water homeostasis through the release of water from cells rather than the up-take of water as seen At-PNP-A. PNP-B could therefore also be involved in plant defence mechanisms to pathogens where plants induce desiccation of infected leaves, thereby ridding the plant of the relevant pathogen. , Thesis (MSc) -- Faculty of Science and Agriculture, 2012
- Full Text:
- Date Issued: 2012
- Authors: Affun, Ogheneochuko Janet
- Date: 2012
- Subjects: Rice , Plant hormones , Water-electrolyte imbalances
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/24354 , vital:62644
- Description: Maintenance of water and solute homeostasis is a key requirement for living systems, and in vertebrates, homeostasis is in part achieved by natriuretic peptides (NP), a family of peptide hormones. A related family of peptide hormones have also been found in the plant kingdom. Plant natriuretic peptides (PNP) are a novel class of plant proteins with two closely related homologous genes (AtPNP-A and AtPNP-B) identified in the model plant Arabidopsis thaliana. AtPNP-A has been extensively studied and evidence obtained points to a role in plant water homeostasis. No research has been conducted on the function of PNP-B proteins. In this study, we focus on the bioinformatic analysis of the PNP-B gene in various plants, as well investigating whether PNP-B plays a role in water homeostasis in rice plants exposed to drought stress. Basic local alignment search tool (BLAST) queries of the ―The Gene Index‖, EST and available plant genome databases revealed the presence of the PNP-B mRNA in rice, oil seed rape, oak, leafy spurge, poplar, sugarcane, pepper, cotton, apple and maize. All the identified genome sequences contained a predicted intron/insert, which was not present in the related mRNA sequences. However, RT-PCR analysis revealed the presence of the 101 bp insert in the 976 bp amplified rice PNP-B (OsPNP-B) cDNA and therefore expression was optimized for the protein encoded by only the exon2 sequence as this contained the predicted active site region of PNP-B. OsPNP-B was shown to be translated to a protein of 14 kDa with a sequence similarity to AtPNP-B (54percent), AtPNP-A (37percent) and CjBAp12 (55percent), suggesting two possible functions for PNP-B viz water homeostasis and/or pathogenesis defence. To determine whether PNP-B is involved in water homeostasis, total protein extracted from 4 weeks old (4 leaves stage) rice plants subjected to drought treatment for a period of 24, 48, 72, 120, 168 and 240hrs were resolved by 17percent SDS-PAGE and analysed by western blot analysis. The PNP-B protein was found to be down-regulated during drought stress, implying that PNP-B may play a role in water homeostasis through the release of water from cells rather than the up-take of water as seen At-PNP-A. PNP-B could therefore also be involved in plant defence mechanisms to pathogens where plants induce desiccation of infected leaves, thereby ridding the plant of the relevant pathogen. , Thesis (MSc) -- Faculty of Science and Agriculture, 2012
- Full Text:
- Date Issued: 2012
The design, synthesis and antiplasmodial activity of a series of halogenated fosmidomycin analogues and hybrid drugs
- Authors: Afolayan, Anthonia Folake
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64370 , vital:28538
- Description: Malaria continues to be a devastating disease and a major cause of death in sub-Saharan Africa. With resistance against most of the available antimalarial drugs, there is a need for ongoing research and development of antimalarial agents. Fosmidomycin and its acetyl analogue FR900098 have been identified as potent inhibitors of Plasmodium falciparum, the causative agent of the most deadly form of malaria. Clinical trials of these agents have revealed poor absorption due to their high hydrophilicity. In the present studies the effect of halogenation of the acyl chain as well as the biological effect of extending the acyl sidechain was explored. This provided the basis on which fosmidomycin hybrids were designed to investigate the feasibility of hybrid extending into NADPH binding pocket. Synthesis of a series of halogenated FR900098 analogues was carried out in three stages. This included i) The introduction of the phosphonate group by reaction with 1,3dibromopropane in an Arbuzov reaction, ii) The introduction of a hydroxamate group by reaction of the propyl phosphonate by means of a nucleophilic substitution reaction with BocNHOBn and iii) The introduction of a halogenated acyl side chain on a protected fosmidomycin backbone. The synthesis of fosmidomycin-hybrids for which chloroquinefosmidomycin hybrids were used as the prototype, involved convergence of the two separately constructed moieties i.e. fosmidomycin and the quinoline moieties in a covalent linkage. The quinoline moiety was easily synthesized from the reaction of 4,7dichloroquinoline with 1,2-diamino ethane. The aminoquinoline so formed resulted in chloroquine-fosmidomycin hybrids 3.8 and 3.9 when reacted with halogenated FR900098 analogues. Antiplasmodial assays were conducted on the chloroquine-fosmidomycin hybrids and the halogenated fosmidomycin derivatives against the chloroquine resistant Gambian FCR-3 strain of P. falciparum. The most potent iodoacetyl fosmidomycin analogues 2.21 gave an IC50 value of 5.54 µM which is eight times more potent than the known antiplasmodial FR900098 which gave an IC50 value of 41.67 µM. All the halogenated FR900098 analogues showed better antiplasmodial activity than their non-halogenated derivatives. This indicated that the presence of halogens in the FR900098 analogues contributes to their biological Chapter 1 Literature review activity. The acetyl and propyl linked hybrids 3.8 and 3.9 showed potent antiplasmodial activity with IC50 values of 0.18 and 0.82 µM respectively. These were by far the most potent hybrids synthesized and provided leads for a new class of promising antimalarial agents. Preliminary E. coli DXR enzyme inhibition assays were carried out on the halogenated fosmidomycin analogues. The results showed good inhibition of the enzyme by the phosphonic acids of the chloroacetyl and chloropropyl analogues 2.1 and 2.2 respectively. Molecular modelling of the compounds on E. coli (PDB code: 2EGH) and P. falciparum (PDB code: 3AUA) DXR showed strong binding of the halogenated fosmidomycin analogues while the hybrids in the absence of docked NADPH showed minimum binding to the enzymes.
- Full Text:
- Date Issued: 2012
- Authors: Afolayan, Anthonia Folake
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: text , Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/64370 , vital:28538
- Description: Malaria continues to be a devastating disease and a major cause of death in sub-Saharan Africa. With resistance against most of the available antimalarial drugs, there is a need for ongoing research and development of antimalarial agents. Fosmidomycin and its acetyl analogue FR900098 have been identified as potent inhibitors of Plasmodium falciparum, the causative agent of the most deadly form of malaria. Clinical trials of these agents have revealed poor absorption due to their high hydrophilicity. In the present studies the effect of halogenation of the acyl chain as well as the biological effect of extending the acyl sidechain was explored. This provided the basis on which fosmidomycin hybrids were designed to investigate the feasibility of hybrid extending into NADPH binding pocket. Synthesis of a series of halogenated FR900098 analogues was carried out in three stages. This included i) The introduction of the phosphonate group by reaction with 1,3dibromopropane in an Arbuzov reaction, ii) The introduction of a hydroxamate group by reaction of the propyl phosphonate by means of a nucleophilic substitution reaction with BocNHOBn and iii) The introduction of a halogenated acyl side chain on a protected fosmidomycin backbone. The synthesis of fosmidomycin-hybrids for which chloroquinefosmidomycin hybrids were used as the prototype, involved convergence of the two separately constructed moieties i.e. fosmidomycin and the quinoline moieties in a covalent linkage. The quinoline moiety was easily synthesized from the reaction of 4,7dichloroquinoline with 1,2-diamino ethane. The aminoquinoline so formed resulted in chloroquine-fosmidomycin hybrids 3.8 and 3.9 when reacted with halogenated FR900098 analogues. Antiplasmodial assays were conducted on the chloroquine-fosmidomycin hybrids and the halogenated fosmidomycin derivatives against the chloroquine resistant Gambian FCR-3 strain of P. falciparum. The most potent iodoacetyl fosmidomycin analogues 2.21 gave an IC50 value of 5.54 µM which is eight times more potent than the known antiplasmodial FR900098 which gave an IC50 value of 41.67 µM. All the halogenated FR900098 analogues showed better antiplasmodial activity than their non-halogenated derivatives. This indicated that the presence of halogens in the FR900098 analogues contributes to their biological Chapter 1 Literature review activity. The acetyl and propyl linked hybrids 3.8 and 3.9 showed potent antiplasmodial activity with IC50 values of 0.18 and 0.82 µM respectively. These were by far the most potent hybrids synthesized and provided leads for a new class of promising antimalarial agents. Preliminary E. coli DXR enzyme inhibition assays were carried out on the halogenated fosmidomycin analogues. The results showed good inhibition of the enzyme by the phosphonic acids of the chloroacetyl and chloropropyl analogues 2.1 and 2.2 respectively. Molecular modelling of the compounds on E. coli (PDB code: 2EGH) and P. falciparum (PDB code: 3AUA) DXR showed strong binding of the halogenated fosmidomycin analogues while the hybrids in the absence of docked NADPH showed minimum binding to the enzymes.
- Full Text:
- Date Issued: 2012
Gender paper to be presented to the ANC Policy Conference 2012: discussion document
- African National Congress (ANC)
- Authors: African National Congress (ANC)
- Date: 2012-02-01
- Subjects: South Africa -- Politics and government -- 1994- , Social planning -- South Africa
- Language: English
- Type: book , text
- Identifier: http://hdl.handle.net/10962/68675 , vital:29304
- Description: This document is informed by the struggles of women in the fight against colonialism and apartheid which were also encapsulated in the Women’s Charter of 1954. The discussion is also premised on the charter that women drew up in 1993, prior to the 1994 elections. Our Constitution, in its quest to protect and promote gender equality in South Africa, drew largely from these documents.
- Full Text:
- Date Issued: 2012-02-01
- Authors: African National Congress (ANC)
- Date: 2012-02-01
- Subjects: South Africa -- Politics and government -- 1994- , Social planning -- South Africa
- Language: English
- Type: book , text
- Identifier: http://hdl.handle.net/10962/68675 , vital:29304
- Description: This document is informed by the struggles of women in the fight against colonialism and apartheid which were also encapsulated in the Women’s Charter of 1954. The discussion is also premised on the charter that women drew up in 1993, prior to the 1994 elections. Our Constitution, in its quest to protect and promote gender equality in South Africa, drew largely from these documents.
- Full Text:
- Date Issued: 2012-02-01
Suicide - a global overview and focus on the South African situation
- Authors: Alonso-Betancourt, O
- Date: 2012
- Subjects: Suicide and Epilepsy Suicide -- South Africa Suicide -- Assessment -- Prevention
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1067 , vital:30560
- Description: As a medical doctor you learn how to deal with death and you feel that your duty is to encourage people to fight against illness for their lives but, when you face suicide, you feel defenseless because it is the person him or herself who chooses to die. Another reason for choosing this topic is that I’m advocating the development and implementation of a Suicide Prevention Program in South Africa and this could be a good forum to talk about this important issue.
- Full Text:
- Date Issued: 2012
- Authors: Alonso-Betancourt, O
- Date: 2012
- Subjects: Suicide and Epilepsy Suicide -- South Africa Suicide -- Assessment -- Prevention
- Language: English
- Type: text , Lectures
- Identifier: http://hdl.handle.net/11260/1067 , vital:30560
- Description: As a medical doctor you learn how to deal with death and you feel that your duty is to encourage people to fight against illness for their lives but, when you face suicide, you feel defenseless because it is the person him or herself who chooses to die. Another reason for choosing this topic is that I’m advocating the development and implementation of a Suicide Prevention Program in South Africa and this could be a good forum to talk about this important issue.
- Full Text:
- Date Issued: 2012
Cost-effective realisation of the Internet of Things
- Andersen, Michael, Irwin, Barry V W
- Authors: Andersen, Michael , Irwin, Barry V W
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427930 , vital:72474 , https://www.researchgate.net/profile/Barry-Irwin/publication/326225063_Cost-effec-tive_realisation_of_the_Internet_of_Things/links/5b3f2262a6fdcc8506ffe75e/Cost-effective-realisation-of-the-Internet-of-Things.pdf
- Description: A hardware and software platform, created to facilitate power usage and power quality measurements along with direct power line actuation is under development. Additional general purpose control and sensing interfaces have been integrated. Measurements are persistently stored on each node to allow asynchronous retrieval of data without the need for a central server. The device communicates using an IEEE 802.15. 4 radio transceiver to create a self-configuring mesh network. Users can interface with the mesh network by connecting to any node via USB and utilising the developed high level API and interactive environment.
- Full Text:
- Date Issued: 2012
- Authors: Andersen, Michael , Irwin, Barry V W
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427930 , vital:72474 , https://www.researchgate.net/profile/Barry-Irwin/publication/326225063_Cost-effec-tive_realisation_of_the_Internet_of_Things/links/5b3f2262a6fdcc8506ffe75e/Cost-effective-realisation-of-the-Internet-of-Things.pdf
- Description: A hardware and software platform, created to facilitate power usage and power quality measurements along with direct power line actuation is under development. Additional general purpose control and sensing interfaces have been integrated. Measurements are persistently stored on each node to allow asynchronous retrieval of data without the need for a central server. The device communicates using an IEEE 802.15. 4 radio transceiver to create a self-configuring mesh network. Users can interface with the mesh network by connecting to any node via USB and utilising the developed high level API and interactive environment.
- Full Text:
- Date Issued: 2012
Synthesis and photophysical properties of peripherally and non-peripherally mercaptopyridine substituted metal free, Mg (II) and Al (III) phthalocyanines
- Arslanoğlu, Yasin, Idowu, Mopelela, Nyokong, Tebello
- Authors: Arslanoğlu, Yasin , Idowu, Mopelela , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243248 , vital:51131 , xlink:href="https://doi.org/10.1016/j.saa.2012.04.004"
- Description: The syntheses and photophysical properties of metallophthalocyanines containing Mg2+ and Al3+ as central metal ions and their unmetallated derivative (complexes 3–8) tetra- substituted at the non-peripheral (α) and peripheral (β) positions with 2-mercaptopyridine are reported. The trends in triplet and fluorescence quantum yields are described for these compounds. The complexes exhibited relatively high triplet quantum yields (ΦT) ranging from 0.33 to 0.54 and fluorescence quantum yields (ΦF) ranging from 0.02 to 0.29. Triplet state lifetimes of the complexes were long ranging from 120 to 460 μs, indicating a potential use of these complexes as photosensitizers.
- Full Text:
- Date Issued: 2012
- Authors: Arslanoğlu, Yasin , Idowu, Mopelela , Nyokong, Tebello
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/243248 , vital:51131 , xlink:href="https://doi.org/10.1016/j.saa.2012.04.004"
- Description: The syntheses and photophysical properties of metallophthalocyanines containing Mg2+ and Al3+ as central metal ions and their unmetallated derivative (complexes 3–8) tetra- substituted at the non-peripheral (α) and peripheral (β) positions with 2-mercaptopyridine are reported. The trends in triplet and fluorescence quantum yields are described for these compounds. The complexes exhibited relatively high triplet quantum yields (ΦT) ranging from 0.33 to 0.54 and fluorescence quantum yields (ΦF) ranging from 0.02 to 0.29. Triplet state lifetimes of the complexes were long ranging from 120 to 460 μs, indicating a potential use of these complexes as photosensitizers.
- Full Text:
- Date Issued: 2012
Design of realistic hybrid marine resource management programs in Oceania
- Aswani, Shankar, Ruddle, Kenneth
- Authors: Aswani, Shankar , Ruddle, Kenneth
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70615 , vital:29681 , https://doi.org/10.2984/67.3.11
- Description: This review article synthesizes the authors' several decades of multidisciplinary natural and social science and applied marine resource management experience in the Asia-Pacific region to examine the strengthening of coastal and marine resource management and conservation using alliances between local communities and external institutions. The objective is to assist the design of resource management and conservation programs that enhance the capacity of coastal communities in Oceania to confront both diminishing marine resources and the effects of climate change by providing guidelines for protecting marine biodiversity and vulnerable ecosystem functions. This article describes a management framework that hybridizes local beliefs and institutions expressed in customary management (CM) with such modern management concepts as marine protected areas (MPAs) and ecosystem-based management (EBM). Hybrid management accommodates the social, political, economic, and cultural contexts of Oceanic communities and, compared with recent or conventional management approaches, can therefore better address fundamental local concerns such as coastal degradation, climate change, sea level rise, weak governance, corruption, limited resources and staff to manage and monitor marine resources, and increasing poverty. Research on the hybridization of management systems demonstrates opportunities to establish context-appropriate EBM and/or other managerial arrangements that include terrestrial and adjacent coastal-marine ecosystems. Formal and informal CM systems are widespread in Oceania and in some parts of Southeast Asia, and if appropriate strategies are employed rapid progress toward hybrid CM-EBM could be enabled.
- Full Text:
- Date Issued: 2012
- Authors: Aswani, Shankar , Ruddle, Kenneth
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/70615 , vital:29681 , https://doi.org/10.2984/67.3.11
- Description: This review article synthesizes the authors' several decades of multidisciplinary natural and social science and applied marine resource management experience in the Asia-Pacific region to examine the strengthening of coastal and marine resource management and conservation using alliances between local communities and external institutions. The objective is to assist the design of resource management and conservation programs that enhance the capacity of coastal communities in Oceania to confront both diminishing marine resources and the effects of climate change by providing guidelines for protecting marine biodiversity and vulnerable ecosystem functions. This article describes a management framework that hybridizes local beliefs and institutions expressed in customary management (CM) with such modern management concepts as marine protected areas (MPAs) and ecosystem-based management (EBM). Hybrid management accommodates the social, political, economic, and cultural contexts of Oceanic communities and, compared with recent or conventional management approaches, can therefore better address fundamental local concerns such as coastal degradation, climate change, sea level rise, weak governance, corruption, limited resources and staff to manage and monitor marine resources, and increasing poverty. Research on the hybridization of management systems demonstrates opportunities to establish context-appropriate EBM and/or other managerial arrangements that include terrestrial and adjacent coastal-marine ecosystems. Formal and informal CM systems are widespread in Oceania and in some parts of Southeast Asia, and if appropriate strategies are employed rapid progress toward hybrid CM-EBM could be enabled.
- Full Text:
- Date Issued: 2012
Welcome Address of the Vice‐Chancellor of Rhodes University, Dr Saleem Badat, to First‐Year students
- Authors: Badat, Saleem
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:7592 , http://hdl.handle.net/10962/d1006583
- Description: From introduction: Our first purpose is to produce knowledge, so that we can better understand our natural and social worlds and also enrich our scientific and cultural heritage. The second purpose of a university is to disseminate knowledge and to develop critical and creative minds. Our goals, yours and ours, must be for you to think imaginatively, ‘effectively and critically;’ to ‘achieve depth in some field of knowledge;’ to appreciate how we ‘gain knowledge and understanding of the universe, of society, and of ourselves;’ to have ‘a broad knowledge of other cultures and other times;’ to critique ideas and views and construct alternatives, and to communicate cogently, orally and in writing. Our final purpose as a university is to undertake community engagement, whether this is as part of academic courses or your voluntary participation in community projects organized by our Community Engagement Office.
- Full Text:
- Date Issued: 2012
Welcome Address of the Vice‐Chancellor of Rhodes University, Dr Saleem Badat, to First‐Year students
- Authors: Badat, Saleem
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:7592 , http://hdl.handle.net/10962/d1006583
- Description: From introduction: Our first purpose is to produce knowledge, so that we can better understand our natural and social worlds and also enrich our scientific and cultural heritage. The second purpose of a university is to disseminate knowledge and to develop critical and creative minds. Our goals, yours and ours, must be for you to think imaginatively, ‘effectively and critically;’ to ‘achieve depth in some field of knowledge;’ to appreciate how we ‘gain knowledge and understanding of the universe, of society, and of ourselves;’ to have ‘a broad knowledge of other cultures and other times;’ to critique ideas and views and construct alternatives, and to communicate cogently, orally and in writing. Our final purpose as a university is to undertake community engagement, whether this is as part of academic courses or your voluntary participation in community projects organized by our Community Engagement Office.
- Full Text:
- Date Issued: 2012
Remembering Jakes - Chancellor, our chancellor
- Authors: Badat, Saleem
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:7584 , http://hdl.handle.net/10962/d1006574
- Description: From introduction: Gerwel was an exceptional, courageous, gifted and pioneering South African intellectual, scholar, leader and citizen. He had a profound commitment to creating a just and humane society. Through a long and distinguished association with the higher education sector, as an academic, dean, vice-chancellor, chairperson of the Committee of University Principals in the early 1990s, chancellor, and chairperson of the Mandela Rhodes Foundation, Gerwel was an outstanding champion of higher education. As chancellor, he challenged Rhodes to become socially conscious and think critically and imaginatively about access, equity and transformation, and about its role in socioeconomic development issues in South Africa, especially in the Eastern Cape.
- Full Text:
- Date Issued: 2012
- Authors: Badat, Saleem
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:7584 , http://hdl.handle.net/10962/d1006574
- Description: From introduction: Gerwel was an exceptional, courageous, gifted and pioneering South African intellectual, scholar, leader and citizen. He had a profound commitment to creating a just and humane society. Through a long and distinguished association with the higher education sector, as an academic, dean, vice-chancellor, chairperson of the Committee of University Principals in the early 1990s, chancellor, and chairperson of the Mandela Rhodes Foundation, Gerwel was an outstanding champion of higher education. As chancellor, he challenged Rhodes to become socially conscious and think critically and imaginatively about access, equity and transformation, and about its role in socioeconomic development issues in South Africa, especially in the Eastern Cape.
- Full Text:
- Date Issued: 2012
Rhodes University 2012 Graduation Ceremonies Address
- Authors: Badat, Saleem
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:7588 , http://hdl.handle.net/10962/d1006579
- Description: From introduction: We take pride in our striving to ensure that we are an environment in which knowledge, understanding and the intellect can flower; in being a leading postgraduate and research university that takes undergraduate studies seriously; in enjoying among the best pass and graduation rates in South Africa; in our increasing engagement with local communities; in the pursuit of equity and excellence, and in being a cosmopolitan institution with students from some 56 countries.
- Full Text:
- Date Issued: 2012
- Authors: Badat, Saleem
- Date: 2012
- Language: English
- Type: text
- Identifier: vital:7588 , http://hdl.handle.net/10962/d1006579
- Description: From introduction: We take pride in our striving to ensure that we are an environment in which knowledge, understanding and the intellect can flower; in being a leading postgraduate and research university that takes undergraduate studies seriously; in enjoying among the best pass and graduation rates in South Africa; in our increasing engagement with local communities; in the pursuit of equity and excellence, and in being a cosmopolitan institution with students from some 56 countries.
- Full Text:
- Date Issued: 2012
Inferring direct DNA binding from ChIP-seq
- Bailey, Timothy L, Machanick, Philip
- Authors: Bailey, Timothy L , Machanick, Philip
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439314 , vital:73565 , https://doi.org/10.1093/nar/gks433
- Description: Genome-wide binding data from transcription factor ChIP-seq experiments is the best source of information for inferring the relative DNA-binding affinity of these proteins in vivo . However, standard motif enrichment analysis and motif discovery approaches sometimes fail to correctly identify the binding motif for the ChIP-ed factor. To overcome this problem, we propose ‘central motif enrichment analysis’ (CMEA), which is based on the observation that the positional distribution of binding sites matching the direct-binding motif tends to be unimodal, well centered and maximal in the precise center of the ChIP-seq peak regions. We describe a novel visualization and statistical analysis tool—CentriMo—that identifies the region of maximum central enrichment in a set of ChIP-seq peak regions and displays the positional distributions of predicted sites. Using CentriMo for motif enrichment analysis, we provide evidence that one transcription factor (Nanog) has different binding affinity in vivo than in vitro , that another binds DNA cooperatively (E2f1), and confirm the in vivo affinity of NFIC, rescuing a difficult ChIP-seq data set. In another data set, CentriMo strongly suggests that there is no evidence of direct DNA binding by the ChIP-ed factor (Smad1). CentriMo is now part of the MEME Suite software package available at http://meme.nbcr.net . All data and output files presented here are available at: http://research.imb.uq.edu.au/t.bailey/sd/Bailey2011a .
- Full Text:
- Date Issued: 2012
- Authors: Bailey, Timothy L , Machanick, Philip
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439314 , vital:73565 , https://doi.org/10.1093/nar/gks433
- Description: Genome-wide binding data from transcription factor ChIP-seq experiments is the best source of information for inferring the relative DNA-binding affinity of these proteins in vivo . However, standard motif enrichment analysis and motif discovery approaches sometimes fail to correctly identify the binding motif for the ChIP-ed factor. To overcome this problem, we propose ‘central motif enrichment analysis’ (CMEA), which is based on the observation that the positional distribution of binding sites matching the direct-binding motif tends to be unimodal, well centered and maximal in the precise center of the ChIP-seq peak regions. We describe a novel visualization and statistical analysis tool—CentriMo—that identifies the region of maximum central enrichment in a set of ChIP-seq peak regions and displays the positional distributions of predicted sites. Using CentriMo for motif enrichment analysis, we provide evidence that one transcription factor (Nanog) has different binding affinity in vivo than in vitro , that another binds DNA cooperatively (E2f1), and confirm the in vivo affinity of NFIC, rescuing a difficult ChIP-seq data set. In another data set, CentriMo strongly suggests that there is no evidence of direct DNA binding by the ChIP-ed factor (Smad1). CentriMo is now part of the MEME Suite software package available at http://meme.nbcr.net . All data and output files presented here are available at: http://research.imb.uq.edu.au/t.bailey/sd/Bailey2011a .
- Full Text:
- Date Issued: 2012
The saga of South African POWs in Angola, 1975-82
- Authors: Baines, Gary F
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69882 , vital:29592 , http://dx.doi.org/10.5787/40-2-999
- Description: This article narrates the story of nine soldiers captured during and shortly after Operation Savannah, the codename for the South African Defence Force invasion of Angola in 1975–6. Eight of these soldiers were captured in Angola in three separate incidents by Angolan and/or Cuban forces, whereas the last was abducted from northern Namibia by SWAPO (the South West Africa Peoples’ Organisation). The article then provides a chronological account of the sequels to this story that interweaves a number of threads: first, the account relates the South African government’s attempts to suppress press coverage of these stories for fear of the political ‘fall-out’ that the matter might cause amongst the white electorate and in case it jeopardised secret negotiations to secure the release of the prisoners; and second, it uncovers the role played by intermediaries, especially the International Committee of the Red Cross (ICRC), in the sensitive and fraught negotiation process. It will be shown that the South African authorities adopted divergent approaches when dealing with SWAPO and the Angolans/Cubans to secure the release of prisoners of war (POWs). This is because the South African authorities regarded the former as involved in an internal insurrection whereas the latter were members of the military forces of sovereign states. Accordingly, they paid lip service to the Geneva Conventions in the case of Angolan and Cuban POWs but treated captured SWAPO cadres as ‘terrorists’ or ‘criminals’.
- Full Text:
- Date Issued: 2012
- Authors: Baines, Gary F
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69882 , vital:29592 , http://dx.doi.org/10.5787/40-2-999
- Description: This article narrates the story of nine soldiers captured during and shortly after Operation Savannah, the codename for the South African Defence Force invasion of Angola in 1975–6. Eight of these soldiers were captured in Angola in three separate incidents by Angolan and/or Cuban forces, whereas the last was abducted from northern Namibia by SWAPO (the South West Africa Peoples’ Organisation). The article then provides a chronological account of the sequels to this story that interweaves a number of threads: first, the account relates the South African government’s attempts to suppress press coverage of these stories for fear of the political ‘fall-out’ that the matter might cause amongst the white electorate and in case it jeopardised secret negotiations to secure the release of the prisoners; and second, it uncovers the role played by intermediaries, especially the International Committee of the Red Cross (ICRC), in the sensitive and fraught negotiation process. It will be shown that the South African authorities adopted divergent approaches when dealing with SWAPO and the Angolans/Cubans to secure the release of prisoners of war (POWs). This is because the South African authorities regarded the former as involved in an internal insurrection whereas the latter were members of the military forces of sovereign states. Accordingly, they paid lip service to the Geneva Conventions in the case of Angolan and Cuban POWs but treated captured SWAPO cadres as ‘terrorists’ or ‘criminals’.
- Full Text:
- Date Issued: 2012
Students’ navigation of the uncharted territories of academic writing
- Bharuthram, Sharita, McKenna, Sioux
- Authors: Bharuthram, Sharita , McKenna, Sioux
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187373 , vital:44626 , xlink:href="https://doi.org/10.1080/18146627.2012.742651"
- Description: Many students enter tertiary education unfamiliar with the ‘norms and conventions’ of their disciplines. Research into academic literacies has shown that in order to succeed in their studies, students are expected to conform to these norms and conventions, which are often unrecognized or seen as ‘common sense’ by lecturers. Students have to develop their own ‘map’ of their programme’s expectations in order to make sense of the seemingly mysterious practices they are expected to take on. This study, undertaken at a University of Technology in South Africa, details students’ perceptions of their writing difficulties and their attempts to navigate their way through various writing tasks. The findings reveal that students experience a range of difficulties and that the students often feel unsupported in their travails with academic writing.
- Full Text:
- Date Issued: 2012
- Authors: Bharuthram, Sharita , McKenna, Sioux
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/187373 , vital:44626 , xlink:href="https://doi.org/10.1080/18146627.2012.742651"
- Description: Many students enter tertiary education unfamiliar with the ‘norms and conventions’ of their disciplines. Research into academic literacies has shown that in order to succeed in their studies, students are expected to conform to these norms and conventions, which are often unrecognized or seen as ‘common sense’ by lecturers. Students have to develop their own ‘map’ of their programme’s expectations in order to make sense of the seemingly mysterious practices they are expected to take on. This study, undertaken at a University of Technology in South Africa, details students’ perceptions of their writing difficulties and their attempts to navigate their way through various writing tasks. The findings reveal that students experience a range of difficulties and that the students often feel unsupported in their travails with academic writing.
- Full Text:
- Date Issued: 2012
A study of four-dimensional oscillator groups and the associated left-invariant control affine systems
- Authors: Biggs, Rory
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164941 , vital:41186
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Department of Mathematics, 2012
- Full Text:
- Date Issued: 2012
- Authors: Biggs, Rory
- Date: 2012
- Subjects: Uncatalogued
- Language: English
- Type: thesis , text , Masters , MSc
- Identifier: http://hdl.handle.net/10962/164941 , vital:41186
- Description: Thesis (MSc)--Rhodes University, Faculty of Science, Department of Mathematics, 2012
- Full Text:
- Date Issued: 2012
What's been built in twenty years?: SADC and Southern Africa's political and regional security culture
- Authors: Bischoff, Paul, 1954-
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161498 , vital:40633
- Description: The sense of region in Southern Africa is based on nationalism and its struggles for national liberation. Unusually, the norms of smaller states initially shaped the region's scope and culture of interaction. First and foremost, cooperation happened in the area of security, an initial focus being to uphold the independence and sovereignty of the state in the face of challenges from apartheid South Africa. As such, rather atypically, intergovernmental security cooperation preceded broad based economic cooperation. This has meant that security and development have remained largely de-linked and this has helped discourage implementing a society or human rights centred approach to security. Cooperation has been made more difficult by disparate political systems with divergent values, cultures, agendas and sensibilities. As such, regionalism reinforces nationalism to the exclusion of development or wider notions of political and social security. The region amounts to a security regime with only a patchy record in advancing security. Therefore, in the face of developmental challenges and unless a degree of strategic coherence along political and policy fronts is reached, after 20 years of SADC the endeavour to institutionalise security in conventional state-centred ways amounts to a scenario of diminishing returns.
- Full Text:
- Date Issued: 2012
- Authors: Bischoff, Paul, 1954-
- Date: 2012
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161498 , vital:40633
- Description: The sense of region in Southern Africa is based on nationalism and its struggles for national liberation. Unusually, the norms of smaller states initially shaped the region's scope and culture of interaction. First and foremost, cooperation happened in the area of security, an initial focus being to uphold the independence and sovereignty of the state in the face of challenges from apartheid South Africa. As such, rather atypically, intergovernmental security cooperation preceded broad based economic cooperation. This has meant that security and development have remained largely de-linked and this has helped discourage implementing a society or human rights centred approach to security. Cooperation has been made more difficult by disparate political systems with divergent values, cultures, agendas and sensibilities. As such, regionalism reinforces nationalism to the exclusion of development or wider notions of political and social security. The region amounts to a security regime with only a patchy record in advancing security. Therefore, in the face of developmental challenges and unless a degree of strategic coherence along political and policy fronts is reached, after 20 years of SADC the endeavour to institutionalise security in conventional state-centred ways amounts to a scenario of diminishing returns.
- Full Text:
- Date Issued: 2012
Adaptations in primary wing moult of southern African Viduidae and their hosts (Estrildidae)
- Bonnevie, Bo T, Oschadleus, Hans-Dieter
- Authors: Bonnevie, Bo T , Oschadleus, Hans-Dieter
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447691 , vital:74667 , https://doi.org/10.2989/00306525.2012.691910
- Description: Primary wing moult patterns in southern African brood-parasitic viduines were compared with those of their estrildid hosts. We searched for similarities in the timing and duration of moult within these closely related species potentially arising from their linked breeding biology and geographical distributions. Contrasting patterns were found between summer and winter rainfall regions, suggesting that climate dominates over phylogenetic effects on moult. Within the summer rainfall region different patterns of moult also emerged, and these generally supported the colonisation hypothesis of the host–brood parasite system. Moult estimates are provided for these taxa for which, until now, data have been mostly descriptive.
- Full Text:
- Date Issued: 2012
- Authors: Bonnevie, Bo T , Oschadleus, Hans-Dieter
- Date: 2012
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447691 , vital:74667 , https://doi.org/10.2989/00306525.2012.691910
- Description: Primary wing moult patterns in southern African brood-parasitic viduines were compared with those of their estrildid hosts. We searched for similarities in the timing and duration of moult within these closely related species potentially arising from their linked breeding biology and geographical distributions. Contrasting patterns were found between summer and winter rainfall regions, suggesting that climate dominates over phylogenetic effects on moult. Within the summer rainfall region different patterns of moult also emerged, and these generally supported the colonisation hypothesis of the host–brood parasite system. Moult estimates are provided for these taxa for which, until now, data have been mostly descriptive.
- Full Text:
- Date Issued: 2012