The role of macrophytes as a refuge and food source for the estuarine isopod Exosphaeroma hylocoetes ()
- Henninger, Tony O, Froneman, P William, Richoux, Nicole B, Hodgson, Alan N
- Authors: Henninger, Tony O , Froneman, P William , Richoux, Nicole B , Hodgson, Alan N
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458360 , vital:75735 , xlink:href="https://doi.org/10.1016/j.ecss.2009.01.01"
- Description: The role of submerged macrophytes as refugia from fish predation and as possible food sources for the estuarine isopod Exosphaeroma hylocoetes (Barnard, K.H., 1940) was investigated. Laboratory experiments tested the effectiveness of artificial vegetation, replicating submerged vegetation, in enabling isopods to elude selected fish predators Rhabdosargus holubi, Glossogobius callidus, Monodactylus falciformis and Clinus cottoides. Isopods preferentially hid in the vegetation (>90%), even in absence of fish. The predatory fish had varying success in finding isopods within the vegetation. Isopod mortality ranged from 2% (R. holubi) to a maximum of 87% (C. cottoides) within vegetation, depending on the fish predator present. Stable isotope and fatty acid analyses ruled out the submerged macrophyte Ruppia maritima and inundated fringing grasses as direct food sources, but highlighted the epiphytic biota (mainly diatoms) found on the submerged vegetation and sediments as more likely food sources. These findings are consistent with gut content analyses. The results suggest that the close association of E. hylocoetes with R. maritima is the result of the vegetation providing the isopod with a refuge against fish predation as well as areas of increased food availability.
- Full Text:
- Authors: Henninger, Tony O , Froneman, P William , Richoux, Nicole B , Hodgson, Alan N
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/458360 , vital:75735 , xlink:href="https://doi.org/10.1016/j.ecss.2009.01.01"
- Description: The role of submerged macrophytes as refugia from fish predation and as possible food sources for the estuarine isopod Exosphaeroma hylocoetes (Barnard, K.H., 1940) was investigated. Laboratory experiments tested the effectiveness of artificial vegetation, replicating submerged vegetation, in enabling isopods to elude selected fish predators Rhabdosargus holubi, Glossogobius callidus, Monodactylus falciformis and Clinus cottoides. Isopods preferentially hid in the vegetation (>90%), even in absence of fish. The predatory fish had varying success in finding isopods within the vegetation. Isopod mortality ranged from 2% (R. holubi) to a maximum of 87% (C. cottoides) within vegetation, depending on the fish predator present. Stable isotope and fatty acid analyses ruled out the submerged macrophyte Ruppia maritima and inundated fringing grasses as direct food sources, but highlighted the epiphytic biota (mainly diatoms) found on the submerged vegetation and sediments as more likely food sources. These findings are consistent with gut content analyses. The results suggest that the close association of E. hylocoetes with R. maritima is the result of the vegetation providing the isopod with a refuge against fish predation as well as areas of increased food availability.
- Full Text:
The syntheses, characterization and fluorescence spectra of novel, octakis (alkylthiophthalocyanato) nickel (II) and palladium (II) complexes
- Ogunbayo, Taofeek Babatunde, Ogunsipe, Abimbola, Nyokong, Tebello
- Authors: Ogunbayo, Taofeek Babatunde , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263386 , vital:53623 , xlink:href="https://doi.org/10.1016/j.dyepig.2009.03.009"
- Description: The syntheses, characterization and fluorescence studies of several {octakis(alkylthio)phthalocyanato} palladium(II) and nickel(II) complexes are presented. The absorption spectra of some of the complexes showed extra peaks which are attributable to non-planar distortion, the extent of which, was found to dependent on alkyl chain length. The fluorescence excitation spectra of the nickel(II) derivatives were not in agreement with their absorption spectra, owing to structural changes upon excitation. Fluorescence quantum yields were very low (more than 1%) for all complexes as a consequence of the open-shell electronic structures of nickel(II) and palladium(II).
- Full Text:
- Authors: Ogunbayo, Taofeek Babatunde , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263386 , vital:53623 , xlink:href="https://doi.org/10.1016/j.dyepig.2009.03.009"
- Description: The syntheses, characterization and fluorescence studies of several {octakis(alkylthio)phthalocyanato} palladium(II) and nickel(II) complexes are presented. The absorption spectra of some of the complexes showed extra peaks which are attributable to non-planar distortion, the extent of which, was found to dependent on alkyl chain length. The fluorescence excitation spectra of the nickel(II) derivatives were not in agreement with their absorption spectra, owing to structural changes upon excitation. Fluorescence quantum yields were very low (more than 1%) for all complexes as a consequence of the open-shell electronic structures of nickel(II) and palladium(II).
- Full Text:
The synthesis and photophysicochemical behaviour of novel water-soluble cationic indium (III) phthalocyanine
- Durmus, Mahmut, Erdoğmuş, Ali, Ogunsipe, Abimbola, Nyokong, Tebello
- Authors: Durmus, Mahmut , Erdoğmuş, Ali , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263419 , vital:53626 , xlink:href="https://doi.org/10.1016/j.dyepig.2009.01.008"
- Description: The syntheses and characterization of 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) and quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) are described. The ground state electronic absorption spectra, photophysics and photochemistry of both dyes in DMSO as well as that of the quaternized compound in aqueous solution are also presented. A comparison of the photophysical and photochemical parameters of the two dyes revealed that quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) was a better photosensitizer than its unquaternized counterpart. The quantum yield values of fluorescence (ΦF), triplet state formation (ΦT) and singlet oxygen formation (ΦΔ) for the cationic dye were found to be 0.03, 0.68 and 0.66 respectively in DMSO; these values were higher than those for 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III), which exhibited values of 0.02, 0.66 and 0.63, respectively in DMSO. The values for the cationic dye in aq. solution were 0.02, 0.59 and 0.56 respectively, suggesting that the water-soluble quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) offers potential as a photosensitizer in photodynamic therapy treatment.
- Full Text:
- Authors: Durmus, Mahmut , Erdoğmuş, Ali , Ogunsipe, Abimbola , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263419 , vital:53626 , xlink:href="https://doi.org/10.1016/j.dyepig.2009.01.008"
- Description: The syntheses and characterization of 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) and quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) are described. The ground state electronic absorption spectra, photophysics and photochemistry of both dyes in DMSO as well as that of the quaternized compound in aqueous solution are also presented. A comparison of the photophysical and photochemical parameters of the two dyes revealed that quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) was a better photosensitizer than its unquaternized counterpart. The quantum yield values of fluorescence (ΦF), triplet state formation (ΦT) and singlet oxygen formation (ΦΔ) for the cationic dye were found to be 0.03, 0.68 and 0.66 respectively in DMSO; these values were higher than those for 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III), which exhibited values of 0.02, 0.66 and 0.63, respectively in DMSO. The values for the cationic dye in aq. solution were 0.02, 0.59 and 0.56 respectively, suggesting that the water-soluble quaternized 2,3-octakis-(3-pyridyloxyphthalocyaninato) indium(III) offers potential as a photosensitizer in photodynamic therapy treatment.
- Full Text:
The synthesis and photophysicochemical properties of low-symmetry zinc phthalocyanine analogues
- Chidawanyika, Wadzanai J U, Nyokong, Tebello
- Authors: Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263397 , vital:53624 , xlink:href="https://doi.org/10.1016/j.jphotochem.2009.06.005"
- Description: The synthesis of a low-symmetry derivative, zinc mono-carboxy substituted phthalocyanine, ZnPc-COOH (4) has been reported. The photochemical and photophysical properties of ZnPc-COOH (4), ZnTMPyPc (5), ZnttbPc (6) and a previously synthesized low-symmetry derivative, ZnttbIPc (7), in various organic solvents are reported. The red-shifting of the spectra of 4 and 5 (relative to that of unsubstituted zinc phthalocyanine, ZnPc) is a function of the electron-donating sulfur-containing substituents attached to the periphery of the molecule. High triplet quantum yields (ФT) generally occur in response to substitution on the zinc phthalocyanine ring periphery. The highest ФT values and triplet lifetimes (τT) occur in DMSO for all derivatives as a result of the solvent's high viscosity. The strongly electron-withdrawing imido fused ring of ZnttbIPc (7) stabilizes it against photo-oxidative degradation relative to the other derivatives.
- Full Text:
- Authors: Chidawanyika, Wadzanai J U , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263397 , vital:53624 , xlink:href="https://doi.org/10.1016/j.jphotochem.2009.06.005"
- Description: The synthesis of a low-symmetry derivative, zinc mono-carboxy substituted phthalocyanine, ZnPc-COOH (4) has been reported. The photochemical and photophysical properties of ZnPc-COOH (4), ZnTMPyPc (5), ZnttbPc (6) and a previously synthesized low-symmetry derivative, ZnttbIPc (7), in various organic solvents are reported. The red-shifting of the spectra of 4 and 5 (relative to that of unsubstituted zinc phthalocyanine, ZnPc) is a function of the electron-donating sulfur-containing substituents attached to the periphery of the molecule. High triplet quantum yields (ФT) generally occur in response to substitution on the zinc phthalocyanine ring periphery. The highest ФT values and triplet lifetimes (τT) occur in DMSO for all derivatives as a result of the solvent's high viscosity. The strongly electron-withdrawing imido fused ring of ZnttbIPc (7) stabilizes it against photo-oxidative degradation relative to the other derivatives.
- Full Text:
The synthesis, cyclic voltammetry and spectroelectrochemical studies of Co (II) phthalocyanines tetra-substituted at the α and β positions with phenylthio groups
- Nombona, Nolwazi, Nyokong, Tebello
- Authors: Nombona, Nolwazi , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264529 , vital:53742 , xlink:href="https://doi.org/10.1016/j.dyepig.2008.06.002"
- Description: Non-peripherally substituted cobalt 1,(4)-(tetraphenylthiophthalocyaninato) and peripherally substituted cobalt 2,(3)-(tetraphenylthiophthalocyaninato) complexes were synthesized. Redox processes were observed at E1/2 = −1.44 V (I), −0.39 V (II), +0.37 V (III), +0.78 V (IV) and 1.15 V (V) for the non-peripherally substituted and at E1/2 = −1.42 V (I), −0.57, −0.39 V (II), +0.27 V (III), +0.79 V (IV) and +1.10 V (V) for the peripherally substituted complexes, respectively. The couples were assigned to CoIPc−2/CoIPc−3 (I), CoIIPc−2/CoIPc−2 (II), CoIIIPc−2/CoIIPc−2 (III), and CoIIIPc−1/CoIIIPc−2 (IV) using spectroelectrochemistry. The last process (V) could not be ascertained by spectroelectrochemistry but is associated with ring oxidation. Upon reduction or oxidation, the Q band of the non-peripherally substituted complex became less red shifted compared to that of its peripherally substituted counterpart.
- Full Text:
- Authors: Nombona, Nolwazi , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264529 , vital:53742 , xlink:href="https://doi.org/10.1016/j.dyepig.2008.06.002"
- Description: Non-peripherally substituted cobalt 1,(4)-(tetraphenylthiophthalocyaninato) and peripherally substituted cobalt 2,(3)-(tetraphenylthiophthalocyaninato) complexes were synthesized. Redox processes were observed at E1/2 = −1.44 V (I), −0.39 V (II), +0.37 V (III), +0.78 V (IV) and 1.15 V (V) for the non-peripherally substituted and at E1/2 = −1.42 V (I), −0.57, −0.39 V (II), +0.27 V (III), +0.79 V (IV) and +1.10 V (V) for the peripherally substituted complexes, respectively. The couples were assigned to CoIPc−2/CoIPc−3 (I), CoIIPc−2/CoIPc−2 (II), CoIIIPc−2/CoIIPc−2 (III), and CoIIIPc−1/CoIIIPc−2 (IV) using spectroelectrochemistry. The last process (V) could not be ascertained by spectroelectrochemistry but is associated with ring oxidation. Upon reduction or oxidation, the Q band of the non-peripherally substituted complex became less red shifted compared to that of its peripherally substituted counterpart.
- Full Text:
The Tett offensive: the global financial crisis
- Authors: Rumney, Reg
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454277 , vital:75332 , https://hdl.handle.net/10520/EJC139939
- Description: Financial journalist Gillian Tett observes in her book - Fool's Gold, How Unrestrained Greed Corrupted a Dream, Shattered Global Markets, and Unleashed a Catastrophe - that the complexity of finance serves the purpose of the financiers well. ''When bankers talkabout derivatives, they delight in swathing the concept in complex jargon,'' she points out. The resulting opacity ''reduces scrutiny and confers power on the few with the ability to pierce the veil''.
- Full Text:
- Authors: Rumney, Reg
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/454277 , vital:75332 , https://hdl.handle.net/10520/EJC139939
- Description: Financial journalist Gillian Tett observes in her book - Fool's Gold, How Unrestrained Greed Corrupted a Dream, Shattered Global Markets, and Unleashed a Catastrophe - that the complexity of finance serves the purpose of the financiers well. ''When bankers talkabout derivatives, they delight in swathing the concept in complex jargon,'' she points out. The resulting opacity ''reduces scrutiny and confers power on the few with the ability to pierce the veil''.
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The unit-based sustainability assessment tool and its use in the UNEP mainstreaming environment and sustainability in African universities partnership
- Togo, Muchaiteyi, Lotz-Sisitka, Heila
- Authors: Togo, Muchaiteyi , Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437409 , vital:73376 , ISBN 978-1-4020-8194-1 , https://doi.org/10.1007/978-3-319-02375-5_15
- Description: This paper reports on the development and use of a Unit-based Sustainability Assessment Tool (USAT) for establishing the status of Education for Sustainable Development initiatives and sustainable development practices in universities. The tool was developed for use in the Swedish/Africa International Training Programme (ITP) on ‘Education for Sustainable De-velopment in Higher Education’ and complements the UNEP Mainstreaming Environment and Sustainability into African Universities (MESA) ‘Education for Sustainable Development Innovations Programmes for Universities in Africa’ materials. The USAT facilitates a quick assessment of the level of inte-gration of sustainability issues in university functions and op-erations, both to benchmark sustainability initiatives and identi-fy new areas for action or improvement. It is based on a unit-based framework which allows for sustainability assessments to be done per division, unit, department, or faculty within uni-versities. Collectively, the unit-based assessments provide for development of an institution wide picture of university sus-tainability.
- Full Text:
- Authors: Togo, Muchaiteyi , Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437409 , vital:73376 , ISBN 978-1-4020-8194-1 , https://doi.org/10.1007/978-3-319-02375-5_15
- Description: This paper reports on the development and use of a Unit-based Sustainability Assessment Tool (USAT) for establishing the status of Education for Sustainable Development initiatives and sustainable development practices in universities. The tool was developed for use in the Swedish/Africa International Training Programme (ITP) on ‘Education for Sustainable De-velopment in Higher Education’ and complements the UNEP Mainstreaming Environment and Sustainability into African Universities (MESA) ‘Education for Sustainable Development Innovations Programmes for Universities in Africa’ materials. The USAT facilitates a quick assessment of the level of inte-gration of sustainability issues in university functions and op-erations, both to benchmark sustainability initiatives and identi-fy new areas for action or improvement. It is based on a unit-based framework which allows for sustainability assessments to be done per division, unit, department, or faculty within uni-versities. Collectively, the unit-based assessments provide for development of an institution wide picture of university sus-tainability.
- Full Text:
The willingness to pay for dusky kob (Argyrosomus japonicus) restocking: using recreational linefishing licence fees to fund stock enhancement in South Africa
- Palmer, Ryan M, Snowball, Jeanette D
- Authors: Palmer, Ryan M , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71322 , vital:29833 , https://doi.org/10.1093/icesjms/fsp075
- Description: The economic feasibility of stock enhancement of Argyrosomus japonicus in South Africa was investigated using a willingness-to-pay (WTP) survey. The pilot study provides a unique example of the use of the contingent valuation method as a valuation tool for a proposed stock enhancement programme. An increase in the cost of a recreational fishing permit is used as a potential vehicle of payment. The median value of the maximum that fishers were willing to pay for a recreational fishing permit was R155 (South African Rand) for frequent fishers and R100 for non-frequent fishers. Analysis showed that a fee of more than R100 excluded up to 50% of anglers from the fishery, but that a fee of R100 excluded only 28% of recreational anglers and would generate an additional R12 million annually from the sale of recreational fishing permits. The estimated costs of set-up and running of a stock enhancement programme are substantially lower than this, suggesting that stock enhancement may be an economically feasible management option that deserves more investigation. The WTP method itself produces robust results and is likely to be an effective tool in the management of the marine environment.
- Full Text:
- Authors: Palmer, Ryan M , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71322 , vital:29833 , https://doi.org/10.1093/icesjms/fsp075
- Description: The economic feasibility of stock enhancement of Argyrosomus japonicus in South Africa was investigated using a willingness-to-pay (WTP) survey. The pilot study provides a unique example of the use of the contingent valuation method as a valuation tool for a proposed stock enhancement programme. An increase in the cost of a recreational fishing permit is used as a potential vehicle of payment. The median value of the maximum that fishers were willing to pay for a recreational fishing permit was R155 (South African Rand) for frequent fishers and R100 for non-frequent fishers. Analysis showed that a fee of more than R100 excluded up to 50% of anglers from the fishery, but that a fee of R100 excluded only 28% of recreational anglers and would generate an additional R12 million annually from the sale of recreational fishing permits. The estimated costs of set-up and running of a stock enhancement programme are substantially lower than this, suggesting that stock enhancement may be an economically feasible management option that deserves more investigation. The WTP method itself produces robust results and is likely to be an effective tool in the management of the marine environment.
- Full Text:
The writing circle by Rozena Maart
- Authors: Naidu, Samantha
- Date: 2009
- Language: English
- Type: Book review , text
- Identifier: vital:26374 , http://hdl.handle.net/10962/54017 , http://www.wasafiri.org/product/wasafiri-issue-57/ , https://orcid.org/0000-0001-9456-8657
- Description: Book review. The writing circle by Rozena Maart.
- Full Text: false
- Authors: Naidu, Samantha
- Date: 2009
- Language: English
- Type: Book review , text
- Identifier: vital:26374 , http://hdl.handle.net/10962/54017 , http://www.wasafiri.org/product/wasafiri-issue-57/ , https://orcid.org/0000-0001-9456-8657
- Description: Book review. The writing circle by Rozena Maart.
- Full Text: false
Thermal ecophysiology of seven carrion‐feeding blowflies in Southern Africa
- Richards, Cameron S, Price, Benjamin W, Villet, Martin H
- Authors: Richards, Cameron S , Price, Benjamin W , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442384 , vital:73980 , https://doi.org/10.1111/j.1570-7458.2009.00824.x
- Description: A variety of temperature thresholds for larvae, pupae, and adults of seven African species of carrion‐feeding blowflies (Diptera: Calliphoridae) was measured and compared to understand their basic thermal biology and the influence of temperature on their behaviour. Calliphoraácroceipalpis (Jaennicke) had consistently lower temperature thresholds than all other species tested for all larval (42.9á░C), pupal (16.6á░C), and adult (45.6á░C) stages. Larvae (50.1á░C) and adults (53.4á░C) of Chrysomyaámarginalis (Robineau‐Desvoidy) had higher upper lethal temperature thresholds than all other species and weighed more than all other species. Pupae and adults of both Chrysomyaáalbiceps (Wiedemann) and Luciliaásericata (Meigen) had similar temperature thresholds, whereas Chrysomyaáputoria (Wiedemann), Chrysomyaáchloropyga (Wiedemann), and Chrysomyaámegacephala (Fabricius) had inconsistent rank temperature thresholds between the larval, pupal, and adult stages. With a few minor exceptions, the nervous activity, muscle activity, and death thresholds in female adult flies responded at higher temperatures than conspecific male flies for all species tested. Similarly, female adult flies weighed consistently more than conspecific male flies for all species tested, except Ca.ácroceipalpis. These data suggest that there is a phylogenetic component to the thermal biology of blowflies, because Ca.ácroceipalpis belongs to a primarily Holarctic genus and shows adaptation to that climate even though it inhabits Africa. Comparisons between these temperature thresholds and the distributions of blowfly species present on three rhinoceros carcasses suggest that blowfly larvae with high upper lethal temperature thresholds (particularly C.ámarginalis) dominate in interspecific competition on the carcass by raising the temperature of the amassed maggots above the thresholds of other carrion‐feeding blowflies, through metabolically generated heat.
- Full Text:
- Authors: Richards, Cameron S , Price, Benjamin W , Villet, Martin H
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442384 , vital:73980 , https://doi.org/10.1111/j.1570-7458.2009.00824.x
- Description: A variety of temperature thresholds for larvae, pupae, and adults of seven African species of carrion‐feeding blowflies (Diptera: Calliphoridae) was measured and compared to understand their basic thermal biology and the influence of temperature on their behaviour. Calliphoraácroceipalpis (Jaennicke) had consistently lower temperature thresholds than all other species tested for all larval (42.9á░C), pupal (16.6á░C), and adult (45.6á░C) stages. Larvae (50.1á░C) and adults (53.4á░C) of Chrysomyaámarginalis (Robineau‐Desvoidy) had higher upper lethal temperature thresholds than all other species and weighed more than all other species. Pupae and adults of both Chrysomyaáalbiceps (Wiedemann) and Luciliaásericata (Meigen) had similar temperature thresholds, whereas Chrysomyaáputoria (Wiedemann), Chrysomyaáchloropyga (Wiedemann), and Chrysomyaámegacephala (Fabricius) had inconsistent rank temperature thresholds between the larval, pupal, and adult stages. With a few minor exceptions, the nervous activity, muscle activity, and death thresholds in female adult flies responded at higher temperatures than conspecific male flies for all species tested. Similarly, female adult flies weighed consistently more than conspecific male flies for all species tested, except Ca.ácroceipalpis. These data suggest that there is a phylogenetic component to the thermal biology of blowflies, because Ca.ácroceipalpis belongs to a primarily Holarctic genus and shows adaptation to that climate even though it inhabits Africa. Comparisons between these temperature thresholds and the distributions of blowfly species present on three rhinoceros carcasses suggest that blowfly larvae with high upper lethal temperature thresholds (particularly C.ámarginalis) dominate in interspecific competition on the carcass by raising the temperature of the amassed maggots above the thresholds of other carrion‐feeding blowflies, through metabolically generated heat.
- Full Text:
Towards a GPS-based TEC prediction model for Southern Africa with feed forward networks
- Habarulema, John B, McKinnell, Lee-Anne, Opperman, Ben D L
- Authors: Habarulema, John B , McKinnell, Lee-Anne , Opperman, Ben D L
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6806 , http://hdl.handle.net/10962/d1004192
- Description: In this paper, first results from a national Global Positioning System (GPS) based total electron content (TEC) prediction model over South Africa are presented. Data for 10 GPS receiver stations distributed through out the country were used to train a feed forward neural network (NN) over an interval of at most five years. In the NN training, validating and testing processes, five factors which are well known to influence TEC variability namely diurnal variation, seasonal variation, magnetic activity, solar activity and the geographic position of the GPS receivers were included in the NN model. The database consisted of 1-min data and therefore the NN model developed can be used to forecast TEC values 1 min in advance. Results from the NN national model (NM) were compared with hourly TEC values generated by the earlier developed NN single station models (SSMs) at Sutherland (32.38°S, 20.81°E) and Springbok (29.67°S, 17.88°E), to predict TEC variations over the Cape Town (33.95°S, 18.47°E) and Upington (28.41°S, 21.26°E) stations, respectively, during equinoxes and solstices. This revealed that, on average, the NM led to an improvement in TEC prediction accuracy compared to the SSMs for the considered testing periods.
- Full Text:
- Authors: Habarulema, John B , McKinnell, Lee-Anne , Opperman, Ben D L
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6806 , http://hdl.handle.net/10962/d1004192
- Description: In this paper, first results from a national Global Positioning System (GPS) based total electron content (TEC) prediction model over South Africa are presented. Data for 10 GPS receiver stations distributed through out the country were used to train a feed forward neural network (NN) over an interval of at most five years. In the NN training, validating and testing processes, five factors which are well known to influence TEC variability namely diurnal variation, seasonal variation, magnetic activity, solar activity and the geographic position of the GPS receivers were included in the NN model. The database consisted of 1-min data and therefore the NN model developed can be used to forecast TEC values 1 min in advance. Results from the NN national model (NM) were compared with hourly TEC values generated by the earlier developed NN single station models (SSMs) at Sutherland (32.38°S, 20.81°E) and Springbok (29.67°S, 17.88°E), to predict TEC variations over the Cape Town (33.95°S, 18.47°E) and Upington (28.41°S, 21.26°E) stations, respectively, during equinoxes and solstices. This revealed that, on average, the NM led to an improvement in TEC prediction accuracy compared to the SSMs for the considered testing periods.
- Full Text:
Traditional food crops as a source of community resilience in Zimbabwe
- Shava, Soul, O'Donoghue, Rob B, Krasny, Marianne E, Zazu, Clayton
- Authors: Shava, Soul , O'Donoghue, Rob B , Krasny, Marianne E , Zazu, Clayton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438804 , vital:73501 , xlink:href="https://doi.org/10.1080/18186870903101982"
- Description: This article draws on local narratives and observations of food sustenance practices in relocated farming communities in Sebakwe, Zimbabwe. Local knowledge on traditional food crops and related agricultural practices was proven to be a source of local community resilience, enabling residents to sustain their livelihoods. Local community agency in maintaining, cultivating and processing traditional food crops was found to sustain their culture and livelihoods, thereby providing community resilience in a changing environment.
- Full Text:
- Authors: Shava, Soul , O'Donoghue, Rob B , Krasny, Marianne E , Zazu, Clayton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/438804 , vital:73501 , xlink:href="https://doi.org/10.1080/18186870903101982"
- Description: This article draws on local narratives and observations of food sustenance practices in relocated farming communities in Sebakwe, Zimbabwe. Local knowledge on traditional food crops and related agricultural practices was proven to be a source of local community resilience, enabling residents to sustain their livelihoods. Local community agency in maintaining, cultivating and processing traditional food crops was found to sustain their culture and livelihoods, thereby providing community resilience in a changing environment.
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Umabatha: Zulu play or Shakespeare translation?
- Authors: Wright, Laurence
- Date: 2009
- Language: English
- Type: text , article
- Identifier: vital:7062 , http://hdl.handle.net/10962/d1007426 , https://www.taylorfrancis.com/books/e/9781351963381/chapters/10.4324%2F9781315264219-12
- Description: preprint , There can be few recent theatrical productions in greater need of interpretative effort than Welcome Msomi’s Umabatha. From its inception debate has raged over the cultural status of the production: was it an authentic expression of Zulu culture, or a tacky piece of ‘blacksploitation’? – to use Russell Vandenbroucke’s term. Was the production pleasing evidence of Shakespeare’s universality, a gift to the colonies returning joyfully to the motherland with interest accruing? Could it perhaps be a case of Zulu culture triumphing over Shakespeare, native invention swamping and overwhelming a colonially-imposed ‘high culture’? Was the show performing ‘Africa’ for the world and, if so, was this the way Africa ought to be represented in the twentieth century? Or were we perhaps looking at a fetishized theatrical commodity, wrenched from any authentic cultural roots, and circulating aimlessly but profitably through a globalised theatrical cosmopolis? Such speculative questions – and there are many others – have regularly jostled each other in the bulky heritage of Umabatha’s reception history. The central problem underlying this chapter is whether it might not be possible to define a basis for a more objective response to some of them, so that the issues involved no longer rest quite so slackly in the realm of mere critical opinion.
- Full Text:
- Authors: Wright, Laurence
- Date: 2009
- Language: English
- Type: text , article
- Identifier: vital:7062 , http://hdl.handle.net/10962/d1007426 , https://www.taylorfrancis.com/books/e/9781351963381/chapters/10.4324%2F9781315264219-12
- Description: preprint , There can be few recent theatrical productions in greater need of interpretative effort than Welcome Msomi’s Umabatha. From its inception debate has raged over the cultural status of the production: was it an authentic expression of Zulu culture, or a tacky piece of ‘blacksploitation’? – to use Russell Vandenbroucke’s term. Was the production pleasing evidence of Shakespeare’s universality, a gift to the colonies returning joyfully to the motherland with interest accruing? Could it perhaps be a case of Zulu culture triumphing over Shakespeare, native invention swamping and overwhelming a colonially-imposed ‘high culture’? Was the show performing ‘Africa’ for the world and, if so, was this the way Africa ought to be represented in the twentieth century? Or were we perhaps looking at a fetishized theatrical commodity, wrenched from any authentic cultural roots, and circulating aimlessly but profitably through a globalised theatrical cosmopolis? Such speculative questions – and there are many others – have regularly jostled each other in the bulky heritage of Umabatha’s reception history. The central problem underlying this chapter is whether it might not be possible to define a basis for a more objective response to some of them, so that the issues involved no longer rest quite so slackly in the realm of mere critical opinion.
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Understanding social learning processes in a citrus farming community of practice
- Authors: Downsborough, Linda
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386949 , vital:68191 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122819"
- Description: This paper focuses on what would traditionally be termed ‘non-formal’ learning processes in the context of a case study examining how citrus farming communities in the Patensie Valley in the Eastern Cape in South Africa were learning conservation practices. Communities of Practice theory was used to provide a conceptual framework for researching these learning interactions. Through historical and other qualitative research methods, I was able to establish that farmers in this community of practice learned mainly through responding to change and uncertainty, through forming and drawing on networks and community structures, through intergenerational learning, and through various interactions with each other. The historical research also pointed to the significance of policy and market-based changes in farmer learning, and their attachment to the land, which is shaped through historical associations with the land, and through embedded relations in farming practice cultures. The paper provides an example of how Communities of Practice theory, complemented by historical research, can be used to understand non-formal learning.
- Full Text:
- Authors: Downsborough, Linda
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/386949 , vital:68191 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122819"
- Description: This paper focuses on what would traditionally be termed ‘non-formal’ learning processes in the context of a case study examining how citrus farming communities in the Patensie Valley in the Eastern Cape in South Africa were learning conservation practices. Communities of Practice theory was used to provide a conceptual framework for researching these learning interactions. Through historical and other qualitative research methods, I was able to establish that farmers in this community of practice learned mainly through responding to change and uncertainty, through forming and drawing on networks and community structures, through intergenerational learning, and through various interactions with each other. The historical research also pointed to the significance of policy and market-based changes in farmer learning, and their attachment to the land, which is shaped through historical associations with the land, and through embedded relations in farming practice cultures. The paper provides an example of how Communities of Practice theory, complemented by historical research, can be used to understand non-formal learning.
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Universal digital inclusion: Beyond connectivity, affordability and capability
- Thinyane, Mamello, Terzoli, Alfredo
- Authors: Thinyane, Mamello , Terzoli, Alfredo
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430876 , vital:72724 , https://ieeexplore.ieee.org/abstract/document/5338911
- Description: Traditionally digital marginalization and exclusion were understood to be a factor of connectivity to the Internet, affordability of the technology, and the capability of the communities to utilize the technology. ICT for development (ICT4D) interventions have been undertaken that address these specific factors of marginalization, however, it remains that com-munities are still excluded from the global knowledge society. In this paper we argue that key factors towards reaching greater inclusion and participation of the digitally marginalized communities, are the knowledge-centricity and context-sensitivity of the undertaken interven-tions. The solutions developed, and the services deployed, must intrin-sically encapsulate the local knowledge within the community of de-ployment. Based on this premise we have developed an architectural framework, named PIASK, that formalizes the contextualization of the developed applications within the socio-technical environment and po-sitions them within the local knowledge system of the community. We highlight the components of this architecture and discuss its implemen-tation through a knowledge platform for a community in South Africa.
- Full Text:
- Authors: Thinyane, Mamello , Terzoli, Alfredo
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430876 , vital:72724 , https://ieeexplore.ieee.org/abstract/document/5338911
- Description: Traditionally digital marginalization and exclusion were understood to be a factor of connectivity to the Internet, affordability of the technology, and the capability of the communities to utilize the technology. ICT for development (ICT4D) interventions have been undertaken that address these specific factors of marginalization, however, it remains that com-munities are still excluded from the global knowledge society. In this paper we argue that key factors towards reaching greater inclusion and participation of the digitally marginalized communities, are the knowledge-centricity and context-sensitivity of the undertaken interven-tions. The solutions developed, and the services deployed, must intrin-sically encapsulate the local knowledge within the community of de-ployment. Based on this premise we have developed an architectural framework, named PIASK, that formalizes the contextualization of the developed applications within the socio-technical environment and po-sitions them within the local knowledge system of the community. We highlight the components of this architecture and discuss its implemen-tation through a knowledge platform for a community in South Africa.
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Using a transdisciplinary framework to examine mathematics classroom talk taking place in and through a second language
- Graven, Mellony, Robertson, Sally-Ann
- Authors: Graven, Mellony , Robertson, Sally-Ann
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69838 , vital:29586 , https://DOI: 10.1007/s11858-018-0952-2
- Description: This paper proposes a transdisciplinary framework to allow for a multifocal exploration of classroom talk practices. It draws on data from a broader study of talk in South African Grade 4 mathematics classrooms where the language of teaching and learning (English) was the home language for neither the teachers nor their students. Lesson transcript data from one teacher’s lessons on fractions are used to demonstrate how working with three strands of conceptual insight from the disciplines of psychology, sociology and linguistics conduces to a potentially richer understanding of a teacher’s use of classroom talk in mediating her students’ mathematical understanding. By drawing on elements of Vygotsky’s sociocultural psychology, we make visible in the lesson data the ways in which this teacher used the ‘everyday’ in trying to navigate her students’ towards more ‘scientific’ conceptualizations of unit fractions. By then taking up aspects of Bernstein’s sociological work, we articulate, and make visible, how societal circumstances impinge on students’ access to exploratory mathematical discourse needed for epistemological access to abstract and generalized mathematical concepts. Finally, through Halliday’s work on the power of particular linguistic registers for meaning-making, we highlight challenges in learning mathematics in and through a second language and reveal the constraints placed on students’ opportunity to maximally exploit the distinct forms of meaning contained within the mathematics register.
- Full Text:
- Authors: Graven, Mellony , Robertson, Sally-Ann
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/69838 , vital:29586 , https://DOI: 10.1007/s11858-018-0952-2
- Description: This paper proposes a transdisciplinary framework to allow for a multifocal exploration of classroom talk practices. It draws on data from a broader study of talk in South African Grade 4 mathematics classrooms where the language of teaching and learning (English) was the home language for neither the teachers nor their students. Lesson transcript data from one teacher’s lessons on fractions are used to demonstrate how working with three strands of conceptual insight from the disciplines of psychology, sociology and linguistics conduces to a potentially richer understanding of a teacher’s use of classroom talk in mediating her students’ mathematical understanding. By drawing on elements of Vygotsky’s sociocultural psychology, we make visible in the lesson data the ways in which this teacher used the ‘everyday’ in trying to navigate her students’ towards more ‘scientific’ conceptualizations of unit fractions. By then taking up aspects of Bernstein’s sociological work, we articulate, and make visible, how societal circumstances impinge on students’ access to exploratory mathematical discourse needed for epistemological access to abstract and generalized mathematical concepts. Finally, through Halliday’s work on the power of particular linguistic registers for meaning-making, we highlight challenges in learning mathematics in and through a second language and reveal the constraints placed on students’ opportunity to maximally exploit the distinct forms of meaning contained within the mathematics register.
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Using pictograms in a patient information leaflet to communicate antiretroviral medicines information to HIV/AIDS patients in rural South Africa:
- Authors: Dowse, Roslind
- Date: 2009
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/156817 , vital:40053 , ISBN
- Description: The objectives were to design a simple, illustrated patient information leaflet for the antiretroviral regimen of stavudine, lamivudine and efavirenz and to evaluate its readability and acceptability in the local Xhosa population. In order to achieve this, a further objective was to design and evaluate illustrations to include in the patient information leaflet which were culturally acceptable and well interpreted. Illustrations or pictograms were designed to illustrate selected instructions appearing in the patient information leaflet and were individually tested in 30 Xhosa participants who had a maximum of 8 years of formal schooling. Results were used to improve the pictograms for inclusion in the patient information leaflet. The patient information leaflet was designed and tested in sixty Xhosa participants with varied levels of education who had stated they could read. Demographic data were collected and they were then asked to read the patient information leaflet, available in both English and isiXhosa, and a series of questions was asked to assess its comprehension and acceptability. The overall average rate of understanding was 95. Six of the 20 questions were located and understood by all participants, and only two questions resulted in less than an 85 correct response. Physical appearance and quantity of information were highly rated and all participants were enthusiastic about the inclusion of pictograms.
- Full Text:
- Authors: Dowse, Roslind
- Date: 2009
- Language: English
- Type: text , book
- Identifier: http://hdl.handle.net/10962/156817 , vital:40053 , ISBN
- Description: The objectives were to design a simple, illustrated patient information leaflet for the antiretroviral regimen of stavudine, lamivudine and efavirenz and to evaluate its readability and acceptability in the local Xhosa population. In order to achieve this, a further objective was to design and evaluate illustrations to include in the patient information leaflet which were culturally acceptable and well interpreted. Illustrations or pictograms were designed to illustrate selected instructions appearing in the patient information leaflet and were individually tested in 30 Xhosa participants who had a maximum of 8 years of formal schooling. Results were used to improve the pictograms for inclusion in the patient information leaflet. The patient information leaflet was designed and tested in sixty Xhosa participants with varied levels of education who had stated they could read. Demographic data were collected and they were then asked to read the patient information leaflet, available in both English and isiXhosa, and a series of questions was asked to assess its comprehension and acceptability. The overall average rate of understanding was 95. Six of the 20 questions were located and understood by all participants, and only two questions resulted in less than an 85 correct response. Physical appearance and quantity of information were highly rated and all participants were enthusiastic about the inclusion of pictograms.
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Utopianism and educational processes in the United Nations Decade of Education for Sustainable Development
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184756 , vital:44269 , xlink:href="https://cjee.lakeheadu.ca/article/view/866"
- Description: Recent international policy literature on Education for Sustainable Development puts forward utopian concepts of sustainable development and transformed learning as objects for educational thinking and practice. This paper, drawing on three illustrative educational investigations with youth in a South African context, critically examines how we might engage with utopian concepts such as those put forward in the United Nations Decade of Education for Sustainable Development. It incorporates an engagement with other related utopian concepts such as democracy and social justice, which feature strongly in post-apartheid societal reconstruction in South Africa. The paper argues that if we are to avoid valuable utopian concepts such as democracy, sustainability, and social justice from becoming doxic knowledge, a reflexive realist orientation might best guide our educational engagements with such concepts. Such an approach to utopianism would take account of contextual realities and situated learning processes, and foster a creativity of action that is constructivist in nature, but not relativist.
- Full Text:
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184756 , vital:44269 , xlink:href="https://cjee.lakeheadu.ca/article/view/866"
- Description: Recent international policy literature on Education for Sustainable Development puts forward utopian concepts of sustainable development and transformed learning as objects for educational thinking and practice. This paper, drawing on three illustrative educational investigations with youth in a South African context, critically examines how we might engage with utopian concepts such as those put forward in the United Nations Decade of Education for Sustainable Development. It incorporates an engagement with other related utopian concepts such as democracy and social justice, which feature strongly in post-apartheid societal reconstruction in South Africa. The paper argues that if we are to avoid valuable utopian concepts such as democracy, sustainability, and social justice from becoming doxic knowledge, a reflexive realist orientation might best guide our educational engagements with such concepts. Such an approach to utopianism would take account of contextual realities and situated learning processes, and foster a creativity of action that is constructivist in nature, but not relativist.
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Utopianism and educational processes in the United Nations Decade of Education for Sustainable Development: a critical reflection
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437367 , vital:73373 , ISBN 978-9086860937 , https://doi.org/10.3920/9789086866915_007
- Description: South Africa and its recent political transformation pro-cess, infused with hope for a better future, is often pre-sented as a utopian form of democracy – or an icon of hope – nationally and in the contemporary global land-scape. Similarly, adult hopes for youth, and youth idealism itself, are often utopian in nature, and young people are often iconised in society as the hope for the future. Re-cent international policy literature on education for sus-tainable development puts forward the utopian concepts of sustainable development and transformed learning (UNESCO 2005a) as objects for educational thinking and practice, and ethical codes such as the Earth Charter (www.earthcharter.org) present useful visions and guid-ance on how to think about and create a better world. But, the realities of the day keep such utopianism in check. Today, South Africa is experiencing xenophobic vio-lence, extreme levels of crime, and continued disenfran-chisement.
- Full Text:
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , book chapter
- Identifier: http://hdl.handle.net/10962/437367 , vital:73373 , ISBN 978-9086860937 , https://doi.org/10.3920/9789086866915_007
- Description: South Africa and its recent political transformation pro-cess, infused with hope for a better future, is often pre-sented as a utopian form of democracy – or an icon of hope – nationally and in the contemporary global land-scape. Similarly, adult hopes for youth, and youth idealism itself, are often utopian in nature, and young people are often iconised in society as the hope for the future. Re-cent international policy literature on education for sus-tainable development puts forward the utopian concepts of sustainable development and transformed learning (UNESCO 2005a) as objects for educational thinking and practice, and ethical codes such as the Earth Charter (www.earthcharter.org) present useful visions and guid-ance on how to think about and create a better world. But, the realities of the day keep such utopianism in check. Today, South Africa is experiencing xenophobic vio-lence, extreme levels of crime, and continued disenfran-chisement.
- Full Text:
Variability in the fractionation of stable isotopes during degradation of two intertidal red algae
- Hill, Jaclyn M, McQuaid, Christopher D
- Authors: Hill, Jaclyn M , McQuaid, Christopher D
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444649 , vital:74257 , https://doi.org/10.1016/j.ecss.2009.02.001
- Description: Macroalgae contribute to intertidal food webs primarily as detritus, with unclear implications for food web studies using stable isotope analysis. We examined differences in the thallus parts of two South African rhodophytes (Gelidium pristoides and Hypnea spicifera) and changes in overall δ13C, δ15N signatures and C:N ratios during degradation in both the field and laboratory. We hypothesized that both degrading macroalgal tissue and macroalgal-derived suspended particulate material (SPM) would show negligible changes in δ13C, but enriched δ15N signatures and lower C:N ratios relative to healthy plants. Only C:N laboratory ratios conformed to predictions, with both species of macroalgae showing decomposition related changes in δ13C and significant depletions in δ15N in both the field and laboratory. In the laboratory, algal tissue and SPM from each species behaved similarly (though some effects were non-significant) but with differing strengths. Gelidium pristoides δ13C increased and C:N ratios decreased over time in tissue and SPM; δ15N became depleted only in SPM. Hypnea spicifera, δ13C, δ15N and C:N ratios all decreased during degradation in both SPM and algae.
- Full Text:
- Authors: Hill, Jaclyn M , McQuaid, Christopher D
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/444649 , vital:74257 , https://doi.org/10.1016/j.ecss.2009.02.001
- Description: Macroalgae contribute to intertidal food webs primarily as detritus, with unclear implications for food web studies using stable isotope analysis. We examined differences in the thallus parts of two South African rhodophytes (Gelidium pristoides and Hypnea spicifera) and changes in overall δ13C, δ15N signatures and C:N ratios during degradation in both the field and laboratory. We hypothesized that both degrading macroalgal tissue and macroalgal-derived suspended particulate material (SPM) would show negligible changes in δ13C, but enriched δ15N signatures and lower C:N ratios relative to healthy plants. Only C:N laboratory ratios conformed to predictions, with both species of macroalgae showing decomposition related changes in δ13C and significant depletions in δ15N in both the field and laboratory. In the laboratory, algal tissue and SPM from each species behaved similarly (though some effects were non-significant) but with differing strengths. Gelidium pristoides δ13C increased and C:N ratios decreased over time in tissue and SPM; δ15N became depleted only in SPM. Hypnea spicifera, δ13C, δ15N and C:N ratios all decreased during degradation in both SPM and algae.
- Full Text: