Electro-oxidation of phenol and its derivatives on poly-Ni (OH) TPhPyPc modified vitreous carbon electrodes
- Authors: Obirai, Joseph , Bedioui, Fethi , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289353 , vital:56625 , xlink:href="https://doi.org/10.1016/j.jelechem.2004.11.006"
- Description: The electrochemical oxidation of phenol and its derivatives using poly-nickel hydroxy tetraphenoxypyrrolephthalocyanine (poly-Ni(OH)TPhPyPc) modified vitreous carbon electrodes are described. The films were formed by the electro-transformation of the electropolymerized pyrrole-substituted phenoxyphthalocyanine poly-NiTPhPyPc modified electrode in aqueous 0.1 M NaOH solution. The poly-Ni(OH)TPhPyPc films showed better stability and resistance to electrode fouling compared to poly-NiTPhPyPc and unmodified electrodes. The resistance to surface fouling and stability can be attributed to the structure of the ring substituent on the phthalocyanine macrocycle and to the particular O–Ni–O bridged architecture of the nickel phthalocyanine film.
- Full Text:
- Date Issued: 2005
Electrocatalytic oxidation and detection of hydrazine at gold electrode modified with iron phthalocyanine complex linked to mercaptopyridine self-assembled monolayer
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286065 , vital:56235 , xlink:href="https://doi.org/10.1016/j.talanta.2005.02.030"
- Description: Electrocatalytic oxidation and detection of hydrazine in pH 7.0 conditions were studied by using gold electrode modified with self-assembled monolayer (SAM) films of iron phthalocyanine (FePc) complex axially ligated to a preformed 4-mercaptopyridine SAMs. The anodic oxidation of hydrazine in neutral pH conditions with FePc-linked-mercaptopyridine-SAM-modified gold electrode occurred at low overpotential (0.35 V versus Ag|AgCl) and the treatment of the voltammetric data showed that it was a pure diffusion-controlled reaction with the involvement of one electron in the rate-determining step. The mechanism for the interaction of hydrazine with the FePc-SAM is proposed to involve the Fe(III)Pc/Fe(II)Pc redox process. Using cyclic voltammetry (CV) and Osteryoung square wave voltammetry (OSWV), hydrazine was detected over a linear concentration range of 1.3 × 10−5 to 9.2 × 10−5 mol/L with low limits of detection (ca. 5 and 11 μM for OSWV and CV, respectively). At concentrations higher than 1.2 × 10−4 mol/L the anodic peak potential shifted to 0.40 V (versus Ag|AgCl), and this was interpreted to be due to kinetic limitations resulting from the saturation of hydrazine and its oxidation products onto the redox-active monolayer film. This type of metallophthalocyanine-SAM-based electrode is a highly promising electrochemical sensor given its ease of fabrication, good catalytic activity, stability, sensitivity and simplicity.
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- Date Issued: 2005
Synthesis, electrochemical and electrocatalytic behaviour of thiophene-appended cobalt, manganese and zinc phthalocyanine complexes
- Authors: Obirai, Joseph , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286103 , vital:56238 , xlink:href="https://doi.org/10.1016/j.electacta.2005.03.024"
- Description: This work reports on the syntheses of new thiophene tetra substituted cobalt, manganese and zinc phthalocyanine (CoTETPc, (Cl)MnTETPc and ZnTETPc) complexes. The redox processes due to the thiophene substituent on the ring of the metallophthalocyanines (MPcs) were observed, in addition to Pc ring and metal (for Co and Mn complexes) based redox activity. The electrocatalytic activity of the CoTETPc complex adsorbed on glassy carbon electrode (GCE) by drop/dry-thermal annealing was investigated using L-cysteine. The modified electrode was stable to repetitive use without any signs of deactivation by oxidation products and was used to determine L-cysteine at concentrations between 0.0015 and 1 mM in pH 4 aqueous conditions.
- Full Text:
- Date Issued: 2005
Effects of central metal on the photophysical and photochemical properties of non-transition metal sulfophthalocyanine
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289337 , vital:56623 , xlink:href="https://doi.org/10.1142/S1088424605000186"
- Description: The photophysical and photochemical properties and quenching (by 1,4-benzoquinone) of metallophthalocyanine sulfonates of aluminium (AlPcSmix), zinc (ZnPcSmix), silicon (SiPcSmix), germanium (GePcSmix) and tin (SnPcSmix) are presented. The quantum yield values of fluorescence (ΦF), triplet state (ΦT), singlet oxygen (ΦΔ) and photodegradation (Φd) were determined and the observed trends in their variation among the complexes discussed in terms of aggregation and the heavy atom effect. 1,4-benzoquinone effectively quenched the fluorescence of the complexes. Quenching analyses gave positive deviations from Stern-Volmer behavior, suggesting the existence of static quenching in addition to dynamic quenching. The static and dynamic components of the quenching were separated using a modified Stern-Volmer equation and the “sphere of action quenching model”. The quenching constant was found to be a function of the radius of the central metal ion.
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- Date Issued: 2005
Hydrogen peroxide oxidation of 2-chlorophenol and 2, 4, 5-trichlorophenol catalyzed by monomeric and aggregated cobalt tetrasulfophthalocyanine
- Authors: Agboola, Bolade , Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289249 , vital:56612 , xlink:href="https://doi.org/10.1016/j.molcata.2004.10.041"
- Description: Cobalt tetrasulfophthalocyanine (CoTSPc) was used to catalyze the oxidation of 2-chlorophenol (2-CP) and 2,4,5-trichlorophenol (TCP) using hydrogen peroxide (H2O2) as the oxidant. This CoTSPc catalyzed hydrogen peroxide oxidation of chlorophenols resulted in the formation of different types of oxidation products depending on the solvent conditions. In water/methanol conditions (where CoTSPc is mainly monomeric, and unionized forms of the phenols), phenol and hydroquinone were the main oxidation products, while in phosphate buffer solutions (pH 7 and 10 for TCP and 2-CP, respectively, where CoTSPc is mainly aggregated, and ionized forms of the phenols), benzoquinone was the main product. In contrast to CoTSPc, other MTSPc complexes studied (AlTSPc, CuTSPc and NiTSPc) exhibited no detectable catalytic effect on the oxidation of chlorophenols under the experimental conditions employed, thus proving the effect of the central metal ions on efficient catalysis of chlorophenol. Reaction pathways are proposed based on the relative time of oxidation products formation.
- Full Text:
- Date Issued: 2005
Surface electrochemistry of iron phthalocyanine axially ligated to 4-mercaptopyridine self-assembled monolayers at gold electrode
- Authors: Ozoemena, Kenneth I , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289282 , vital:56615 , xlink:href="https://doi.org/10.1016/j.jelechem.2005.02.018"
- Description: Surface electrochemical behaviour of a self-immobilised iron phthalocyanine (FePc) ultrathin film, via axial ligation reaction, onto a preformed 4-mercaptopyridine self-assembled monolayer on gold electrode has been described. Electrochemical evidence for the sensor clearly suggested surface-confined, flat “umbrella”-oriented and densely-packed monolayer film structure. The proposed electrochemical sensor exhibited good catalytic activity towards the oxidation of thiocyanate in pH 4.0 medium over a linear range of three decades of concentration (ca. 10−6–10−3 mol dm−3) with a detection limit in the order of ∼10−7 mol dm−3. The sensor exhibited useful potential for the analysis of thiocyanate in human urine and saliva samples. The advantageous properties of this type of electrode as a sensor for thiocyanate lie in its ease of fabrication, excellent catalytic activity, stability, sensitivity and simplicity.
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- Date Issued: 2005
Synthesis and photophysical properties of a covalently linked porphyrin-phthalocyanine conjugate
- Authors: Zhao, Zhixin , Ogunsipe, Abimbola O , Maree, M David , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300358 , vital:57922 , xlink:href="https://doi.org/10.1142/S1088424605000253"
- Description: The synthesis of a phthalocyanine-porphyrin heteropentamer (zinc(II) tetra(5-phenoxy-10,15,20-triphenylporphyrin)) zinc(II) phthalocyanine, (ZnPc-(ZnTPP)4), containing four units of zinc tetraphenylporphyrin linked to a central zinc phthalocyanine macrocycle via an ether linkage is reported. The photophysical parameters of the pentamer are reported in toluene and dimethyl sulfoxide (DMSO). The observed differences in the fluorescence behavior of the pentamer in the two solvents is explained in terms of emission from different states; charge transfer state in DMSO and locally excited state in toluene. The rate constants for fluorescence, intersystem crossing, internal conversion, and of charge and energy transfer are reported for the pentamer. Quantum yields for fluorescence, internal conversion, triplet state and of charge and energy transfer are also reported for the pentamer, ZnPc-(ZnTPP)4 and the mixture of ZnPc and ZnTPP. The latter two parameters are higher in the pentamer compared to a mixture containing ZnPc and ZnTPP.
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- Date Issued: 2005
Playing musement games: Retroduction in social research, with particular reference to indigenous knowledge in environmental and health education
- Authors: Price, Leigh
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373763 , vital:66722 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122701"
- Description: My aim here is to introduce the concept of musement (retroduction or abduction) as an appropriate alternative to deduction and induction, both in indigenous knowledge (IK) specifically and in social science generally. As an example, I will use musement to tentatively address some of the ethical problems of using indigenous knowledge (IK) in environmental education and health education. This paper will therefore be of use both to researchers/educators wanting a discussion of retroduction, and researchers/educators wanting a discussion of indigenous knowledge epistemology and its relationship with ethics. I am arguing, from a perspective that allows a stratified reality (things can be real even if not measurable or actually present), that, we admit retroduction into our list of allowable research logics. In terms of IK, the result of accepting retroduction as a valid logic is that we allow IK to be dynamic and non-reified. It also allows a previously ignored aspect of IK, its spiritual/non-empirical beliefs, to be validated through ethical outcomes experienced in our lives, rather than through the previous criteria of empirical validity. In other words, we ask for IK: does believing in (whatever) adequately explain experience and/or provide optimistic, long term, ethical, appropriate ways of living? Thus, retroduction has the potential to allow IK to contribute to a normative ethics.
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- Date Issued: 2005
Photochemical and photophysical properties of pentoxy-and naphthaloxy appended magnesium and zinc phthalocyanines
- Authors: Maqanda, Wesiwe , Nyokong, Tebello , Maree, David M
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289260 , vital:56613 , xlink:href="https://doi.org/10.1142/S1088424605000435"
- Description: Photochemical and photophysical measurements were conducted on pentoxy and naphthaloxy appended zinc and magnesium phthalocyanines. We describe in this paper the synthesis as well as unexpected photodegradation behavior of naphthaloxy appended magnesium phthalocyanines. General trends are described for quantum yields of photodegradation, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds.
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- Date Issued: 2005
Synthesis, photophysicochemical studies of adjacently tetrasubstituted binaphthalo-phthalocyanines
- Authors: Seotsanyana-Mokhosi, Itumeleng , Chen, Ji-Yao , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289294 , vital:56616 , xlink:href="https://doi.org/10.1142/S108842460500040X"
- Description: Adjacent binaphthalo-phthalocyanines tetra-substituted with phenoxy (4a), 4-carboxyphenoxy (4b) and 4-t-butylphenoxy (4c) groups, as well as the di-substituted 4-carboxyphenoxy (5b) have been synthesized and characterized. The photophysical and photochemical behavior of 4a-c, were compared with those of the corresponding di-substituted derivatives, (5a-c). The secondary substituents on the phenoxy ring have an influence on the aggregation of the molecules and hence on their photophysical properties. All of the complexes exhibit a relatively good conversion of energy from the triplet-excited state to the singlet oxygen. The less aggregated molecule (4c), has the highest singlet oxygen quantum yield. For all the molecules, fluorescence yields are low and they all have relatively shorter triplet lifetimes compared with the unsubstituted zinc phthalocyanine. Increasing the number of ring substituents on these rigid MPc complexes (from complexes 5 to 4) showed a general increase in the triplet state lifetimes and singlet oxygen quantum yields, and a decrease in stability.
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- Date Issued: 2005
Immobilized cobalt (II) phthalocyanine–cobalt (II) porphyrin pentamer at a glassy carbon electrode
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/300322 , vital:57916 , xlink:href="https://doi.org/10.1016/j.elecom.2005.04.019"
- Description: This communication describes the electrochemistry of a novel cobalt phthalocyanine–cobalt porphyrin (cobalt(II)phthalocyanine–cobalt(II)tetra(5-phenoxy-10,15,20-triphenylporphyrin)) (CoPc-(CoTPP)4) immobilised onto a glassy carbon electrode (GCE). The GCE-CoPc-(CoTPP)4 displayed high efficiency as a potential amperometric sensor for hydrogen peroxide (H2O2) in neutral and alkaline pH conditions. Electrochemical and electrocatalytic properties of the pentamer seem to depend mostly on the central CoPc, and partly, on the synergistic effect of the CoPc/CoPP units. The GCE-CoPc-(CoTPP)4 showed very fast amperometric response (∼1 s), with linearities up to ⩾1.50 mM, low detection limits (μM range) and stability (8 weeks) towards the amperometric determination of laboratory and medical solutions of H2O2.
- Full Text:
- Date Issued: 2005
Photophysical and photochemical studies of sulphonated non-transition metal phthalocyanines in aqueous and non-aqueous media
- Authors: Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289271 , vital:56614 , xlink:href="https://doi.org/10.1016/j.jphotochem.2005.03.001"
- Description: The photophysical and photochemical parameters for mixed sulphonated metallophthalocyanine complexes (AlPcSmix, SiPcSmix, GePcSmix, SnPcSmix, and ZnPcSmix) are reported in phosphate buffer saline (PBS, pH 7.4), PBS containing the surfactant Triton X-100, and in dimethylsulphoxide (DMSO). The ground state spectra of SiPcSmix, GePcSmix and SnPcSmix show splitting of the Q-band in DMSO, but the fluorescence spectra have only one band, suggesting that only some components of the mixed complexes fluoresce. In general the quantum yields of fluorescence (ΦF) were smaller in DMSO compared to the aqueous solvents, while quantum yields of triplet state (ΦT) were larger in DMSO. Triplet lifetimes were much lower in aqueous solutions (compared to DMSO) due to the fact that water absorbs strongly around 1108 nm, which corresponds to the triplet energy of a metallophthalocyanine complex. The MPcSmix complexes quenched hydroquinone, and the Stern–Volmer constants follow the order: AlPcSmix > SiPcSmix > GePcSmix > ZnPcSmix > SnPcSmix which is the order of the extinction coefficients (of the low energy band for complexes with split Q-band) of these molecules. The rate constants for fluorescence, intersystem crossing, internal conversion, and photodegradation were determined from the hydroquinone quenching data.
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- Date Issued: 2005
Electropolymerized Pyrrole-Substituted Manganese Phthalocyanine Films for the Electroassisted Biomimetic Catalytic Reduction of Molecular Oxygen
- Authors: Rodrigues, Nazaré Pereira , Obirai, Joe , Nyokong, Tebello , Bedioui, Fethi
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/289372 , vital:56626 , xlink:href="https://doi.org/10.1002/elan.200403064"
- Description: We report for the first time on the electroassisted biomimetic activation of molecular oxygen by a newly prepared electropolymerized polypyrrole-manganese phthalocyanine film. The prepared films and their intervention in the electroassisted catalytic reduction of molecular oxygen were analyzed by cyclic voltammetry and UV-visible spectrophotometry on optically transparent electrodes. The obtained results demonstrate the probable existence of the key-steps responsible for the suggested formation of the highly reactive manganese oxo intermediate.
- Full Text:
- Date Issued: 2005
Photophysical properties of a water-soluble adjacently substituted bisnaphthalophthalocyanine
- Authors: Seotsanyana-Mokhosi, Itumeleng , Nyokong, Tebello
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286091 , vital:56237 , xlink:href="https://doi.org/10.1142/S1088424605000599"
- Description: Spectral properties of a water soluble metal free tetracarboxyphenoxy bisnaphthalo-phthalocyanine (3) were studied in water and organic solvents. It was found that in protic solvents, complex 3 was highly aggregated. The surfactant, Triton X100, and bovineserum albumin (BSA) do not effect disaggregation while cetyl trimethylammonium chloride (CTAC) caused the molecule to disaggregate. The fluorescence quantum yields were higher in the presence of CTAC. Studying the interaction of BSA with complex 3 using fluorometry revealed that BSA is highly quenched by the latter. A 1:1 stoichiometric binding ratio between BSA and the Pc was found. Triplet quantum yields in water containing CTAC were higher than in organic solvents.
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- Date Issued: 2005
Research on indigenous knowledge and its application: A case of wild food plants of Zimbabwe
- Authors: Shava, Soul
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373809 , vital:66725 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122700"
- Description: Research on indigenous knowledge should go beyond documenting and interpreting it. Rather, it should stimulate inquiry into its application in present day community development and education settings. This study intends to steer indigenous knowledge research towards practical application initiatives. The study documents wild food plants of Zimbabwe, highlights some popular wild food plants, and cites some commercially marketed wild food plants and makes recommendations on the application of indigenous knowledge of wild food plants in community and educational settings.
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- Date Issued: 2005
Social epistemology and its politically correct words: Avoiding absolutism, relativism, consensualism, and vulgar pragmatism
- Authors: Price, Leigh
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373833 , vital:66727 , xlink:href="https://hdl.handle.net/10520/ejc-cristal-v10-n1-a7"
- Description: Where social epistemology has been applied in environmental education research, certain words have come to be associated with it, such as, "social," "contextualized," "strategic," "political," "pragmatic," "democratic," and "participatory." In this paper, I first suggest interpretations of these words that potentially avoid absolutism, relativism, consensualism, and vulgar pragmatism. I then identify interpretations that succumb to these problems. To support my argument, I draw on Peircean scholars, critical realist scholars, and scholars who rely on a tranche of metaphor that evoke images of connections, partnerships, webs, and rhizomes. These writers suggest a social epistemology in which in which relationships, not objects, are primary.
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- Date Issued: 2005
The contribution and direct-use value of livestock to rural livelihoods in the Sand River catchment, South Africa
- Authors: Shackleton, Charlie M , Shackleton, Sheona E , Netshiluvhi, T R , Mathabela, F R
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181335 , vital:43720 , xlink:href="https://doi.org/10.2989/10220110509485870"
- Description: The productive functions of livestock ownership in communal areas are multipurpose in character, comprising a mix of stock types and a range of goods and services used. When all these multiple uses are accounted for, the cash and direct-use returns of livestock in communal areas can be comparable to commercial systems, although temporally and spatially variable. Yet previous work has generally excluded small stock from such analyses, as well as benefits and costs to non-owning households. This paper presents empirical results of a study in the Sand River catchment, assessing the benefits and costs accruing to owners and non-owners for both cattle and goats within a livelihoods analysis framework. Results indicate that cattle are used for a greater variety of goods and services than are goats. The savings value represented the most important function, followed by milk and then manure. Even if savings value was excluded, cattle ownership made a significant contribution to local livelihoods. Goats also provided a net positive benefit, represented largely by the savings value, followed by meat and cash sales. Non-owners also benefited through donations of manure, milk, draught and meat for free, or at a cheaper rate than alternatives. The majority of non-owners aspired to livestock ownership, although the risk of theft of animals was of growing concern. Averaged across the whole catchment, the net value of goods and services from livestock was just over R400 per hectare, with an annual return to capital of 36%. Cattle contributed the bulk of the value by virtue of their greater numbers and larger size, but on a per kilogramme basis goats provided higher value. Many of the goods and services obtained from livestock were not enumerated in regional or national economic statistics.
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- Date Issued: 2005
Cholera in KwaZulu-Natal: Probing institutional governmentality and indigenous hand-washing practices
- Authors: O'Donoghue, Rob B
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/373574 , vital:66704 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122699"
- Description: The paper reviews education activities in a successful anti-cholera campaign amongst rural communities in eastern southern Africa. It is centred on probing how a modern institutional governmentality was relatively blind to an historical legacy of Nguni hand-washing practices and came to exclude use of simple tests for coliform contamination in rural health education activities. The study examines institutional processes, probing discontinuities between the health education message and the complex social ecology of cholera. In so doing, it uncovers how a post-apartheid institutional rhetoric of participation, empowerment and social transformation is playing out in communicative interventions to instil healthier practices amongst the rural poor. Institutional perspectives such as this are rooted in an institutional legacy of appropriation and control. Despite the current rhetoric of participation, instrumental orientations are being sustained as the radical critique of struggle for freedom and change gives way, through comfortable submission and intellectual conformity, to an instrumental conservatism in many post-apartheid institutional settings today. The study notes and probes a surprising resonance between the ecology of the disease and an intergenerational social capital of indigenous hand-washing practices. The evidence suggests that these patterns of hand-washing practice would have served to contain the disease in earlier times and points to this social capital as a focus for co-engaged action on environment and health concerns. The findings suggest that an opposing of institutional and indigenous knowledge is not a simple matter and that moving beyond a legacy of cultural exclusion and marginalisation remains a challenge as the first decade of post-apartheid democratic governance comes to a close.
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- Date Issued: 2005
Customary Sea Tenure in Oceania as a Case of Rights-based Fishery Management: Does it Work?
- Authors: Shankar, Aswani
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439071 , vital:73542 , xlink:href="https://doi.org/10.1007/s11160-005-4868-x"
- Description: This paper outlines the general characteristics of customary sea tenure (CST) in Oceania and identifies areas in which these characteristics overlap with modern rights-based fisheries management systems such as ITQs and CDQs. It also examines the effectiveness of CST regimes at regulating marine resource use and access by focusing on a particular case from the Solomon Islands. The institutional robustness or vulnerability of CST is assessed by examining various performance criteria for two communities in the Roviana Lagoon, Western Solomons. These criteria include people’s (1) settlement patterns in relation to their property, (2) cultural consensus, (3) cultural attitudes with regard to governance and management, and (4) fishing efforts and yields. The results show that a number of historical processes have shaped CST systems into heterogeneous and dynamic institutions, and that CST regimes can vary even on small geographical scales. Understanding the circumstances in which CST regimes are more likely to be successful has facilitated the design and implementation of co-management fishery prescriptions (MPAs) for protecting particular species and habitats in the region. More generally, the paper proposes that by discerning the effectiveness of local governance institutions at regulating resource use and access – taking into consideration that these are embedded in particular historical and political contexts – we can better predict whether or not an introduced fishery management system will work. This knowledge can also assist in designing hybrid management schemes that cross-fertilize community-based management, modern rights-based fishery management (e.g., ITQs and CDQs), and other government regulations. This integration is particularly relevant when these policies are to be implemented in coastal communities that have or have had traditional rights-based fishery management systems of their own and/or are more socio-culturally homogeneous. Given the long history of failed fishery management, it is now of vital importance to design innovative fishery management prescriptions that integrate natural and social science research more comprehensively.
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- Date Issued: 2005
Multivariate analysis of honeybees, Apis mellifera Linnaeus (Hymenoptera: Apidae) of the northeastern and southern regions of Algeria.
- Authors: Barour, C , Tahar, A , Radloff, Sarah E , Hepburn, H Randall
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451976 , vital:75092 , https://hdl.handle.net/10520/EJC32628
- Description: Morphometric characters of worker honeybees, Apis mellifera Linnaeus, were analysed by multivariate methods to characterize their populations in the northeastern and southern regions (ecological-climatological zones) of Algeria, from 36°55' to 32°25'N and 3°39' to 8°22'E. Three morphoclusters were identified by using principal components and linear discriminant analyses. The bees are identified as Apis mellifera intermissa Buttel-Reepen.
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- Date Issued: 2005