The distribution and abundance of the endangered Knysna seahorse Hippocampus capensis (Pisces: Syngnathidae) in South African estuaries
- Lockyear, Jacqueline F, Hecht, Thomas, Kaiser, Horst, Teske, Peter R
- Authors: Lockyear, Jacqueline F , Hecht, Thomas , Kaiser, Horst , Teske, Peter R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445714 , vital:74416 , https://doi.org/10.2989/16085910609503897
- Description: The occurrence, distribution and abundance of the endangered Knysna seahorse Hippocampus capensis in 10 estuaries on South Africa's warm temperate south coast, were investigated. Seahorses were found only in the Knysna, Swartvlei and Keurbooms estuaries. Sex ratios were even and, in most cases, more adults were found than juveniles. During the first year of study, seahorse densities were higher in the Swartvlei and Keurbooms estuaries than in the comparatively larger Knysna Estuary but, during the second year, seahorses were absent from the Keurbooms estuary, and the population size in the Swartvlei Estuary had decreased by more than 80%. These results suggest that, although the two smaller estuaries are able to support comparatively high densities of seahorses, population sizes may fluctuate considerably. Population size estimates for the Knysna Estuary were similar to those obtained in a previous study, suggesting that this estuary may represent a more stable environment and may thus be particularly important for the survival and conservation of this species.
- Full Text:
- Authors: Lockyear, Jacqueline F , Hecht, Thomas , Kaiser, Horst , Teske, Peter R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/445714 , vital:74416 , https://doi.org/10.2989/16085910609503897
- Description: The occurrence, distribution and abundance of the endangered Knysna seahorse Hippocampus capensis in 10 estuaries on South Africa's warm temperate south coast, were investigated. Seahorses were found only in the Knysna, Swartvlei and Keurbooms estuaries. Sex ratios were even and, in most cases, more adults were found than juveniles. During the first year of study, seahorse densities were higher in the Swartvlei and Keurbooms estuaries than in the comparatively larger Knysna Estuary but, during the second year, seahorses were absent from the Keurbooms estuary, and the population size in the Swartvlei Estuary had decreased by more than 80%. These results suggest that, although the two smaller estuaries are able to support comparatively high densities of seahorses, population sizes may fluctuate considerably. Population size estimates for the Knysna Estuary were similar to those obtained in a previous study, suggesting that this estuary may represent a more stable environment and may thus be particularly important for the survival and conservation of this species.
- Full Text:
The effect of Ge, Si and Sn phthalocyanine photosensitizers on cell proliferation and viability of human oesophageal carcinoma cells
- Seotsanyana-Mokhosi, Itumeleng, Kresfelder, Tina, Abrahamse, Heidi, Nyokong, Tebello
- Authors: Seotsanyana-Mokhosi, Itumeleng , Kresfelder, Tina , Abrahamse, Heidi , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286115 , vital:56241 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2005.12.004"
- Description: The photodynamic activity of water soluble mixed sulfonated metallophthalocyanines complexes: GePcSmix, SnPcSmix and SiPcSmix on human oesophageal carcinoma (SNO) cells are reported, and compared with the activity of the unmetallated H2PcSmix and of the newly synthesized water soluble adjacently substituted binaphthalo phthalocyanine (complex 3). The alkaline phosphate (ALP) showed damage to the cell membrane in the presence of complex 3 without irradiation. The GePcSmix complex caused a relatively large increase in inflammation and a high intracellular ATP.
- Full Text:
- Authors: Seotsanyana-Mokhosi, Itumeleng , Kresfelder, Tina , Abrahamse, Heidi , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286115 , vital:56241 , xlink:href="https://doi.org/10.1016/j.jphotobiol.2005.12.004"
- Description: The photodynamic activity of water soluble mixed sulfonated metallophthalocyanines complexes: GePcSmix, SnPcSmix and SiPcSmix on human oesophageal carcinoma (SNO) cells are reported, and compared with the activity of the unmetallated H2PcSmix and of the newly synthesized water soluble adjacently substituted binaphthalo phthalocyanine (complex 3). The alkaline phosphate (ALP) showed damage to the cell membrane in the presence of complex 3 without irradiation. The GePcSmix complex caused a relatively large increase in inflammation and a high intracellular ATP.
- Full Text:
The effect of water hyacinth, Eichhornia crassipes (Martius) SolmsLaubach (Pontederiaceae), on benthic biodiversity in two impoundments on the New Year's River, South Africa
- Midgley, John M, Hill, Martin P, Villet, Martin H
- Authors: Midgley, John M , Hill, Martin P , Villet, Martin H
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442358 , vital:73978 , https://doi.org/10.2989/16085910609503868
- Description: Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), forms thick mats that affect water resource utilisation, but little is known about its impacts on biodiversity in aquatic ecosystems. The benthic invertebrate community and algal biomass were sampled under water hyacinth mats and in water hyacinth-free water over a 13-month period, using artificial substrates in New Year's Dam, Eastern Cape Province, South Africa. The number of families per substrate (U = 796.5, P 0.001), number of individuals per substrate (U = 620.5, P 0.001), Shannon-Weiner Diversity Index (U = 1 038, P 0.001), Margalef's Richness index (U = 1 136, P 0.002), Pielou's Evenness Index (U = 1 230, P 0.001) and chlorophyll a (U = 678, P 0.01) were all significantly lower under water hyacinth mats than in water hyacinth-free zones. Similarly, multivariate analyses showed more diversity in invertebrate communities in open water than under water hyacinth. Thus, the control of water hyacinth is important, in order to prevent both ecological and economic impacts of biodiversity loss.
- Full Text:
- Authors: Midgley, John M , Hill, Martin P , Villet, Martin H
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442358 , vital:73978 , https://doi.org/10.2989/16085910609503868
- Description: Water hyacinth, Eichhornia crassipes (Martius) Solms-Laubach (Pontederiaceae), forms thick mats that affect water resource utilisation, but little is known about its impacts on biodiversity in aquatic ecosystems. The benthic invertebrate community and algal biomass were sampled under water hyacinth mats and in water hyacinth-free water over a 13-month period, using artificial substrates in New Year's Dam, Eastern Cape Province, South Africa. The number of families per substrate (U = 796.5, P 0.001), number of individuals per substrate (U = 620.5, P 0.001), Shannon-Weiner Diversity Index (U = 1 038, P 0.001), Margalef's Richness index (U = 1 136, P 0.002), Pielou's Evenness Index (U = 1 230, P 0.001) and chlorophyll a (U = 678, P 0.01) were all significantly lower under water hyacinth mats than in water hyacinth-free zones. Similarly, multivariate analyses showed more diversity in invertebrate communities in open water than under water hyacinth. Thus, the control of water hyacinth is important, in order to prevent both ecological and economic impacts of biodiversity loss.
- Full Text:
The identification of mammalian species through the classification of hair patterns using image pattern recognition
- Moyo, Thamasanqa, Bangay, Shaun D, Foster, Gregory G
- Authors: Moyo, Thamasanqa , Bangay, Shaun D , Foster, Gregory G
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432938 , vital:72914 , https://doi.org/10.1145/1108590.1108619
- Description: The identification of mammals through the use of their hair is important in the fields of forensics and ecology. The application of computer pattern recognition techniques to this process provides a means of reducing the subjectivity found in the process, as manual techniques rely on the interpretation of a human expert rather than quantitative measures. The first application of image pattern recognition techniques to the classification of African mammalian species using hair patterns is presented. This application uses a 2D Gabor filter-bank and motivates the use of moments to classify hair scale patterns. Application of a 2D Gabor filter-bank to hair scale processing provides results of 52% accuracy when using a filter-bank of size four and 72% accuracy when using a filter-bank of size eight. These initial results indicate that 2D Gabor filters produce information that may be successfully used to classify hair according to images of its patterns.
- Full Text:
- Authors: Moyo, Thamasanqa , Bangay, Shaun D , Foster, Gregory G
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432938 , vital:72914 , https://doi.org/10.1145/1108590.1108619
- Description: The identification of mammals through the use of their hair is important in the fields of forensics and ecology. The application of computer pattern recognition techniques to this process provides a means of reducing the subjectivity found in the process, as manual techniques rely on the interpretation of a human expert rather than quantitative measures. The first application of image pattern recognition techniques to the classification of African mammalian species using hair patterns is presented. This application uses a 2D Gabor filter-bank and motivates the use of moments to classify hair scale patterns. Application of a 2D Gabor filter-bank to hair scale processing provides results of 52% accuracy when using a filter-bank of size four and 72% accuracy when using a filter-bank of size eight. These initial results indicate that 2D Gabor filters produce information that may be successfully used to classify hair according to images of its patterns.
- Full Text:
The sharing of pension benefits on divorce: An inevitable affair?
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186723 , vital:44528 , xlink:href="Print only"
- Description: One of the invariable consequences of divorce is that the patrimonial assets of the marriage have to be divided up between the two parties. At a primary level, the way in which this will occur will be determined by a number of factors: the matrimonial property regime under which the parties had been married; the relevant provisions of the Divorce Act (Act 70 of 1979) that deal with the question of the patrimonial consequences of divorce; as well as any agreement on this often ticklish matter that can be reached by the parties prior to the divorce action. Approximately fourteen years ago, section 7 of the Divorce Act was amended to allow a divorced spouse to share in the pension interests of the other spouse. There is some polemic, though, as to the interpretation of this provision: in particular, it is not clear whether this pension benefit will automatically form part of the assets that are susceptible to division, or whether a prayer to this effect must specifically be sought. After a consideration of the current legal position regarding the sharing of pension benefits generally, this note will examine this specific debate.
- Full Text:
- Authors: Glover, Graham B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/186723 , vital:44528 , xlink:href="Print only"
- Description: One of the invariable consequences of divorce is that the patrimonial assets of the marriage have to be divided up between the two parties. At a primary level, the way in which this will occur will be determined by a number of factors: the matrimonial property regime under which the parties had been married; the relevant provisions of the Divorce Act (Act 70 of 1979) that deal with the question of the patrimonial consequences of divorce; as well as any agreement on this often ticklish matter that can be reached by the parties prior to the divorce action. Approximately fourteen years ago, section 7 of the Divorce Act was amended to allow a divorced spouse to share in the pension interests of the other spouse. There is some polemic, though, as to the interpretation of this provision: in particular, it is not clear whether this pension benefit will automatically form part of the assets that are susceptible to division, or whether a prayer to this effect must specifically be sought. After a consideration of the current legal position regarding the sharing of pension benefits generally, this note will examine this specific debate.
- Full Text:
The six-legged flying squad
- Villet, Martin H, Muller, Nikite W J
- Authors: Villet, Martin H , Muller, Nikite W J
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442677 , vital:74020 , https://journals.co.za/doi/pdf/10.10520/AJA1729830X_227
- Description: How do bugs and insects help forensic entomologists to settle disputes and solve crimes? Martin Villet and Nikite Muller explain.
- Full Text:
- Authors: Villet, Martin H , Muller, Nikite W J
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442677 , vital:74020 , https://journals.co.za/doi/pdf/10.10520/AJA1729830X_227
- Description: How do bugs and insects help forensic entomologists to settle disputes and solve crimes? Martin Villet and Nikite Muller explain.
- Full Text:
Trade in reed-based craft products in rural villages in the Eastern Cape, South Africa
- Pereira, Taryn, Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Pereira, Taryn , Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181290 , vital:43716 , xlink:href="https://doi.org/10.1080/03768350600927235"
- Description: Selling traditional craft products made from fibrous plants is an important source of income for economically vulnerable rural women. In the Eastern Cape Province of South Africa, Cyperus textilis and Juncus kraussii have been used for centuries to make products of functional and cultural importance, such as sleeping mats and baskets. In the former Transkei village clusters of Mpozolo and Ntubeni, female crafters harvest the raw material and make and sell the products in their communities and in nearby towns. Interviews with 40 of them revealed what the trade contributes to their livelihoods and what enhances or limits their success. The findings show that crafting contributes vital income to vulnerable households, on average 26 ± 4 per cent of annual household cash income, over 40 per cent for the poorest households and 5–15 per cent for wealthier households. Lack of access to non-traditional markets was identified as the main constraint on the trade.
- Full Text:
- Authors: Pereira, Taryn , Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181290 , vital:43716 , xlink:href="https://doi.org/10.1080/03768350600927235"
- Description: Selling traditional craft products made from fibrous plants is an important source of income for economically vulnerable rural women. In the Eastern Cape Province of South Africa, Cyperus textilis and Juncus kraussii have been used for centuries to make products of functional and cultural importance, such as sleeping mats and baskets. In the former Transkei village clusters of Mpozolo and Ntubeni, female crafters harvest the raw material and make and sell the products in their communities and in nearby towns. Interviews with 40 of them revealed what the trade contributes to their livelihoods and what enhances or limits their success. The findings show that crafting contributes vital income to vulnerable households, on average 26 ± 4 per cent of annual household cash income, over 40 per cent for the poorest households and 5–15 per cent for wealthier households. Lack of access to non-traditional markets was identified as the main constraint on the trade.
- Full Text:
Unique electrochemical behavior of tantalum (V) phthalocyanine
- Tau, Prudence, Nyokong, Tebello
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286139 , vital:56243 , xlink:href="https://doi.org/10.1142/S1088424606000090"
- Description: The electrochemical and spectroscopic behavior of tantalum(V) phthalocyanine are presented. The NMR spectra is consistent with the lack of symmetry of the complex. Cyclic (CV) and square wave (SWV) voltammetries, and spectroelectrochemistry, were employed in the study of the complex. Two one-electron reductions and a simultaneous 4-electron reduction were observed. Reduction occurs first at the metal to form a Ta(IV) species, followed by ring based processes.
- Full Text:
- Authors: Tau, Prudence , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286139 , vital:56243 , xlink:href="https://doi.org/10.1142/S1088424606000090"
- Description: The electrochemical and spectroscopic behavior of tantalum(V) phthalocyanine are presented. The NMR spectra is consistent with the lack of symmetry of the complex. Cyclic (CV) and square wave (SWV) voltammetries, and spectroelectrochemistry, were employed in the study of the complex. Two one-electron reductions and a simultaneous 4-electron reduction were observed. Reduction occurs first at the metal to form a Ta(IV) species, followed by ring based processes.
- Full Text:
Urban forestry–A cinderella science in South Africa?
- Authors: Shackleton, Charlie M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183092 , vital:43911 , xlink:href="https://doi.org/10.2989/10295920609505255"
- Description: The benefits of forests (in their broadest sense) and of trees to the natural environment and rural communities are well known throughout the world, including in South Africa (e.g. see chapters in Lawes et al. 2004). The presence of these benefits has also been extrapolated to urban situations, where natural forests and veld might be left in situ, or trees planted in public spaces, or in private gardens. These benefits span the social, aesthetic, health, environmental and economic spheres.
- Full Text:
- Authors: Shackleton, Charlie M
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/183092 , vital:43911 , xlink:href="https://doi.org/10.2989/10295920609505255"
- Description: The benefits of forests (in their broadest sense) and of trees to the natural environment and rural communities are well known throughout the world, including in South Africa (e.g. see chapters in Lawes et al. 2004). The presence of these benefits has also been extrapolated to urban situations, where natural forests and veld might be left in situ, or trees planted in public spaces, or in private gardens. These benefits span the social, aesthetic, health, environmental and economic spheres.
- Full Text:
Urban fuelwood demand and markets in a small town in South Africa: Livelihood vulnerability and alien plant control
- Shackleton, Charlie M, McConnachie, Matthew M, Chauke, Maphambe I, Mentz, J, Sutherland, F, Gambiza, James, Jones, R
- Authors: Shackleton, Charlie M , McConnachie, Matthew M , Chauke, Maphambe I , Mentz, J , Sutherland, F , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181224 , vital:43710 , xlink:href="https://doi.org/10.1080/13504500609469697"
- Description: Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function.
- Full Text:
- Authors: Shackleton, Charlie M , McConnachie, Matthew M , Chauke, Maphambe I , Mentz, J , Sutherland, F , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181224 , vital:43710 , xlink:href="https://doi.org/10.1080/13504500609469697"
- Description: Fuelwood is the primary energy for most households throughout the developing world. With increasing urbanization and declining local availability of fuelwood, a growing proportion of households obtain their fuelwood by purchasing it. These fuelwood markets are the key nexus in supply and demand scenarios and can be potentially significant points for intervention to address energy security amongst the urban poor. This paper reports on the fuelwood demand and marketing in a small town in South Africa. Despite the availability of more modern fuels and state subsidization of electricity, fuelwood was still used by half the households. Annual demand was 1.2 t per household. Over half of the households bought their fuelwood requirements because local stocks were limited. Those households that did collect their own fuelwood were significantly poorer than households that purchased fuelwood, as well as households that did not use fuelwood at all. Fuelwood markets operated through 45-60 vendors who transported fuelwood from further afield. Income from the fuelwood trade was low, but was strongly linked to hours worked. Thus, vendors working a full week did earn a meaningful income, especially in the context of high unemployment in the area. Fuelwood vendors also provided casual employment opportunities for unskilled labour. Most vendors harvested fuelwood from commonage lands, with most of the wood being from alien species. Local stocks of wood are declining in the face of constant transformation of commonage to residential areas, and a national water and biodiversity conservation programme to eradicate alien plants. This decline poses a threat to the financial viability of fuelwood markets. Yet, an opportunity exists to incorporate the vendors into the alien plant clearing programme, since they already perform such a function.
- Full Text:
UV-Visible and Electrochemical Monitoring of Carbon Monoxide Release by Donor Complexes to Myoglobin Solutions and to Electrodes Modified with Films Containing Hemin
- Obirai, Joseph C, Hamadi, Sara, Ithurbide, Aurélie, Wartelle, Corinne, Nyokong, Tebello, Zagal, José, Top, Siden, Bedioui, Fethi
- Authors: Obirai, Joseph C , Hamadi, Sara , Ithurbide, Aurélie , Wartelle, Corinne , Nyokong, Tebello , Zagal, José , Top, Siden , Bedioui, Fethi
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283906 , vital:56001 , xlink:href="https://doi.org/10.1002/elan.200603571"
- Description: This study reports on the evaluation of the CO donating behavior of tricarbonyl dichloro ruthenium(II) dimer ([Ru(CO)3Cl2]2) and 1,3-dimethoxyphenyl tricarbonyl chromium (C6H3(MeO)2Cr(CO)3) complex by UV-visible technique and electrochemical technique. The CO release was monitored by following the modifications of the UV-visible features of MbFe(II) in phosphate buffer solution and the redox features of reduced Hemin, HmFe(II), confined at the surface of a vitreous carbon electrode. In the latter case, the interaction between the hemin-modified electrode and the released CO was seen through the observation of an increase of the reduction current related to the FeIII/FeII redox process of the immobilized porphyrin. While the ruthenium-based complex, ([Ru(CO)3Cl2]2), depended on the presence of Fe(II) species to release CO, it was found that the chromium-based complex released spontaneously CO. This was facilitated by illuminating and/or simple stirring of the solution containing the complex.
- Full Text:
- Authors: Obirai, Joseph C , Hamadi, Sara , Ithurbide, Aurélie , Wartelle, Corinne , Nyokong, Tebello , Zagal, José , Top, Siden , Bedioui, Fethi
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283906 , vital:56001 , xlink:href="https://doi.org/10.1002/elan.200603571"
- Description: This study reports on the evaluation of the CO donating behavior of tricarbonyl dichloro ruthenium(II) dimer ([Ru(CO)3Cl2]2) and 1,3-dimethoxyphenyl tricarbonyl chromium (C6H3(MeO)2Cr(CO)3) complex by UV-visible technique and electrochemical technique. The CO release was monitored by following the modifications of the UV-visible features of MbFe(II) in phosphate buffer solution and the redox features of reduced Hemin, HmFe(II), confined at the surface of a vitreous carbon electrode. In the latter case, the interaction between the hemin-modified electrode and the released CO was seen through the observation of an increase of the reduction current related to the FeIII/FeII redox process of the immobilized porphyrin. While the ruthenium-based complex, ([Ru(CO)3Cl2]2), depended on the presence of Fe(II) species to release CO, it was found that the chromium-based complex released spontaneously CO. This was facilitated by illuminating and/or simple stirring of the solution containing the complex.
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Variation in the timing of reproduction of the four-striped field mouse, Rhabdomys pumilio, in the Eastern Cape Province, South Africa
- Jackson, Claire, Bernard, Ric T F
- Authors: Jackson, Claire , Bernard, Ric T F
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447101 , vital:74584 , https://doi.org/10.1080/15627020.2006.11407367
- Description: We used the four-striped field mouse, Rhabdomys pumilio (Sparrmann, 1784), to test the hypothesis that reproduction in a small, short-lived mammal will be opportunistic, characterized by temporal and spatial variation in the timing of events, and only be inhibited under harsh and predictable winter conditions. Field mice were trapped for three years in two regions of the Eastern Cape Province of South Africa, one that experienced a predictable and harsh winter (Mountain Zebra National Park; MZNP) and the other which experienced a milder winter (Thomas Baines Nature Reserve; TBNR). There was no winter inhibition of reproduction at TBNR, while at MZNP female reproductive activity was inhibited but males continued to produce spermatozoa in winter. We interpret this flexibility in the timing of reproduction as supporting an opportunistic reproductive strategy which may be an adaptation to the seasonal and often unpredictable climate of the region.
- Full Text:
- Authors: Jackson, Claire , Bernard, Ric T F
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447101 , vital:74584 , https://doi.org/10.1080/15627020.2006.11407367
- Description: We used the four-striped field mouse, Rhabdomys pumilio (Sparrmann, 1784), to test the hypothesis that reproduction in a small, short-lived mammal will be opportunistic, characterized by temporal and spatial variation in the timing of events, and only be inhibited under harsh and predictable winter conditions. Field mice were trapped for three years in two regions of the Eastern Cape Province of South Africa, one that experienced a predictable and harsh winter (Mountain Zebra National Park; MZNP) and the other which experienced a milder winter (Thomas Baines Nature Reserve; TBNR). There was no winter inhibition of reproduction at TBNR, while at MZNP female reproductive activity was inhibited but males continued to produce spermatozoa in winter. We interpret this flexibility in the timing of reproduction as supporting an opportunistic reproductive strategy which may be an adaptation to the seasonal and often unpredictable climate of the region.
- Full Text:
Wireless Security Tools
- Janse van Rensburg, Johanna, Irwin, Barry V W
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429867 , vital:72647 , https://digifors.cs.up.ac.za/issa/2006/Proceedings/Research/113_Paper.pdf
- Description: Detecting and investigating intrusive Internet activity is an ever-present challenge for network administrators and security researchers. Network monitoring can generate large, unmanageable amounts of log data, which further complicates distinguishing between illegitimate and legiti-mate traffic. Considering the above issue, this article has two aims. First, it describes an investigative methodology for network monitoring and traffic review; and second, it discusses results from applying this method. The method entails a combination of network telescope traffic capture and visualisation. Observing traffic from the perspective of a dedicated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Com-plimenting this, visual analysis facilitates the rapid review and correla-tion of events, thereby utilizing human intelligence in the identification of scanning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tai-lor made 3D scatter-plot visualisation. As the results show, the visuali-sation saliently conveys anomalous patterns, and further analysis re-veals that these patterns are indicative of covert network probing activi-ty. By incorporating visual analysis with traditional approaches, such as textual log review and the use of an intrusion detection system, this re-search contributes improved insight into network scanning incidents.
- Full Text:
- Authors: Janse van Rensburg, Johanna , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429867 , vital:72647 , https://digifors.cs.up.ac.za/issa/2006/Proceedings/Research/113_Paper.pdf
- Description: Detecting and investigating intrusive Internet activity is an ever-present challenge for network administrators and security researchers. Network monitoring can generate large, unmanageable amounts of log data, which further complicates distinguishing between illegitimate and legiti-mate traffic. Considering the above issue, this article has two aims. First, it describes an investigative methodology for network monitoring and traffic review; and second, it discusses results from applying this method. The method entails a combination of network telescope traffic capture and visualisation. Observing traffic from the perspective of a dedicated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Com-plimenting this, visual analysis facilitates the rapid review and correla-tion of events, thereby utilizing human intelligence in the identification of scanning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tai-lor made 3D scatter-plot visualisation. As the results show, the visuali-sation saliently conveys anomalous patterns, and further analysis re-veals that these patterns are indicative of covert network probing activi-ty. By incorporating visual analysis with traditional approaches, such as textual log review and the use of an intrusion detection system, this re-search contributes improved insight into network scanning incidents.
- Full Text:
‘Exploring the practical adequacy of the human rights, social justice, inclusivity and healthy environment policy discourse in South Africa’s National Curriculum Statement’
- Schudel, Ingrid J, Lotz-Sisitka, Heila
- Authors: Schudel, Ingrid J , Lotz-Sisitka, Heila
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391180 , vital:68629 , xlink:href="https://www.tandfonline.com/doi/full/10.1080/13504620701284860"
- Description: This article examines the practical adequacy of the recent defining of a normative framework for the South African National Curriculum Statement that focuses on the relationship between human rights, social justice and a healthy environment. This politically framed and socially critical normative framework has developed in response to socio-political and socio-ecological histories in postapartheid curriculum transformation processes. The article critically considers the process of working with a normative framework in the defining of environmental education teaching and learning interactions, and seeks not only to explore the policy discourse critically, but also to explore what it is about the world that makes it work in different ways. Drawing on Sayer’s perspectives on the possibilities of enabling ‘situated universalism’ as a form of normative theory, and case-based data from a teacher professional development programme in the Makana District (where the authors live and work), the article probes the relationship between the establishment of a ‘universalising’ normative framework to guide national curriculum, and situated engagements with this framework in/as democratic process. In this process it questions whether educators should adopt the ‘norms’ as presented by society and simply universalize and implement them as prescribed by curriculum statements, or whether educators should adopt the strategies of postmodernists and reduce normative frameworks to relations of power situated in particular contexts.
- Full Text:
- Authors: Schudel, Ingrid J , Lotz-Sisitka, Heila
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/391180 , vital:68629 , xlink:href="https://www.tandfonline.com/doi/full/10.1080/13504620701284860"
- Description: This article examines the practical adequacy of the recent defining of a normative framework for the South African National Curriculum Statement that focuses on the relationship between human rights, social justice and a healthy environment. This politically framed and socially critical normative framework has developed in response to socio-political and socio-ecological histories in postapartheid curriculum transformation processes. The article critically considers the process of working with a normative framework in the defining of environmental education teaching and learning interactions, and seeks not only to explore the policy discourse critically, but also to explore what it is about the world that makes it work in different ways. Drawing on Sayer’s perspectives on the possibilities of enabling ‘situated universalism’ as a form of normative theory, and case-based data from a teacher professional development programme in the Makana District (where the authors live and work), the article probes the relationship between the establishment of a ‘universalising’ normative framework to guide national curriculum, and situated engagements with this framework in/as democratic process. In this process it questions whether educators should adopt the ‘norms’ as presented by society and simply universalize and implement them as prescribed by curriculum statements, or whether educators should adopt the strategies of postmodernists and reduce normative frameworks to relations of power situated in particular contexts.
- Full Text: