Effects of prophylactic progesterone in decomposing tissues on the development of Chrysomya chloropyga (Wiedeman)(Diptera Calliphoridae)
- da Silva, C, Villet, Martin H
- Authors: da Silva, C , Villet, Martin H
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442020 , vital:73950 , https://hdl.handle.net/10520/EJC32654
- Description: Medico-legal forensic entomology is often concerned with the estimation of postmortem intervals (PMI), the time elapsed since the death of a body, by estimating the age of maggots if they are found on a body. These estimates can be complicated by the presence of a variety of drugs that may be present in dead bodies, including steroids such as hydrocortisone (Musvasva et al. 2001).
- Full Text:
- Date Issued: 2006
- Authors: da Silva, C , Villet, Martin H
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/442020 , vital:73950 , https://hdl.handle.net/10520/EJC32654
- Description: Medico-legal forensic entomology is often concerned with the estimation of postmortem intervals (PMI), the time elapsed since the death of a body, by estimating the age of maggots if they are found on a body. These estimates can be complicated by the presence of a variety of drugs that may be present in dead bodies, including steroids such as hydrocortisone (Musvasva et al. 2001).
- Full Text:
- Date Issued: 2006
Electrocatalytic oxidation of thiocyanate, L-cysteine and 2-mercaptoethanol by self-assembled monolayer of cobalt tetraethoxy thiophene phthalocyanine
- Sehlotho, Nthapo, Nyokong, Tebello
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283814 , vital:55993 , xlink:href="https://doi.org/10.1016/j.electacta.2005.12.024"
- Description: Catalytic activity of a self-assembled monolayer (SAM) of cobalt tetra ethoxythiophene phthalocyanine (CoTEThPc-SAM) complex towards oxidation of thiocyanate (SCN−), L-cysteine (CYS) and 2-mercaptoethanol (2-ME) is reported. The oxidation of thiocyanate occurs via a two electron transfer, whereas L-cysteine and 2-ME require 1 electron. The oxidation of thiocyanate is catalysed by ring based processes, while L-cysteine is catalysed by both CoIII/CoII process and by ring based processes. 2-ME is catalysed by CoIII/CoII process. The oxidation of thiocyanate on CoTEThPc was performed in acid media instead of basic media commonly employed. The reaction order was found to be unity for all the analytes, showing that only one molecule of analyte interacts with one molecule of the catalyst during the rate determining step.
- Full Text:
- Date Issued: 2006
- Authors: Sehlotho, Nthapo , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/283814 , vital:55993 , xlink:href="https://doi.org/10.1016/j.electacta.2005.12.024"
- Description: Catalytic activity of a self-assembled monolayer (SAM) of cobalt tetra ethoxythiophene phthalocyanine (CoTEThPc-SAM) complex towards oxidation of thiocyanate (SCN−), L-cysteine (CYS) and 2-mercaptoethanol (2-ME) is reported. The oxidation of thiocyanate occurs via a two electron transfer, whereas L-cysteine and 2-ME require 1 electron. The oxidation of thiocyanate is catalysed by ring based processes, while L-cysteine is catalysed by both CoIII/CoII process and by ring based processes. 2-ME is catalysed by CoIII/CoII process. The oxidation of thiocyanate on CoTEThPc was performed in acid media instead of basic media commonly employed. The reaction order was found to be unity for all the analytes, showing that only one molecule of analyte interacts with one molecule of the catalyst during the rate determining step.
- Full Text:
- Date Issued: 2006
Electropolymerizable iron (III) and cobalt (II) dicyanophenoxy tetraphenylporphyrin complexes
- Ozoemena, Kenneth I, Zhao, Zhixin, Nyokong, Tebello
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286080 , vital:56236 , xlink:href="https://doi.org/10.1016/j.inoche.2005.11.024"
- Description: Solution and solid phase electrochemical features of 5-[4-(3,4-dicyanophenoxy)phenyl],10,15,20-triphenylporphyrin complexes of iron(III) (FeCNOTPP(Cl)) and cobalt(II) (CoCNOTPP) have been described. These novel asymmetric dicyanophenoxy-derivatised cobalt and iron porphyrin complexes were electropolymerised onto glassy carbon electrodes, which in aqueous solutions, gave surface concentrations (ca. 10−10 mol cm−2) typical of monolayer coverages. The films also exhibited excellent stability and electrocatalysis towards the direct detection of important analytes as nitrite, nitric oxide, and hydrogen peroxide in aqueous solutions.
- Full Text:
- Date Issued: 2006
- Authors: Ozoemena, Kenneth I , Zhao, Zhixin , Nyokong, Tebello
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/286080 , vital:56236 , xlink:href="https://doi.org/10.1016/j.inoche.2005.11.024"
- Description: Solution and solid phase electrochemical features of 5-[4-(3,4-dicyanophenoxy)phenyl],10,15,20-triphenylporphyrin complexes of iron(III) (FeCNOTPP(Cl)) and cobalt(II) (CoCNOTPP) have been described. These novel asymmetric dicyanophenoxy-derivatised cobalt and iron porphyrin complexes were electropolymerised onto glassy carbon electrodes, which in aqueous solutions, gave surface concentrations (ca. 10−10 mol cm−2) typical of monolayer coverages. The films also exhibited excellent stability and electrocatalysis towards the direct detection of important analytes as nitrite, nitric oxide, and hydrogen peroxide in aqueous solutions.
- Full Text:
- Date Issued: 2006
Evaluation of rate of swelling and erosion of verapamil (VRP) sustained-release matrix tablets
- Khamanga, Sandile M, Walker, Roderick B
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184232 , vital:44192 , xlink:href="https://doi.org/10.1080/03639040600599822"
- Description: Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.
- Full Text:
- Date Issued: 2006
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184232 , vital:44192 , xlink:href="https://doi.org/10.1080/03639040600599822"
- Description: Tablets manufactured in-house were compared to a marketed sustained-release product of verapamil to investigate the rate of hydration, erosion, and drug-release mechanism by measuring the wet and subsequent dry weights of the products. Swelling and erosion rates depended on the polymer and granulating fluid used, which ultimately pointed to their permeability characteristics. Erosion rate of the marketed product was highest, which suggests that the gel layer that formed around these tablets was weak as opposed to the robust and resistant layers of test products. Anomalous and near zero-order transport mechanisms were dominant in tests and commercial product, respectively.
- Full Text:
- Date Issued: 2006
First record of predation by the alien invasive freshwater fish Micropterus salmoides L.(Centrarchidae) on migrating estuarine fishes in South Africa
- Weyl, Olaf L F, Lewis, Hylton
- Authors: Weyl, Olaf L F , Lewis, Hylton
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446852 , vital:74565 , https://doi.org/10.1080/15627020.2006.11407365
- Description: This study presents results from stomach content analysis of 123 largemouth bass, Micropterus salmoides, sampled at the mouth of the fishway leading into a 3 m high weir at the tidal limit of the Kowie River, Eastern Cape Province (33°32‘39“S, 26°46‘ 52.3“E). Stomach contents from small (120–240 mm fork length, FL) and large (250–440mm FL) fish were analysed separately. Fish were the dominant prey item in small bass, followed by terrestrial insects and Potamonautes sp. In large bass, Potamonautes sp. dominated the stomach contents, while fish were less dominant and other prey items were considered incidental. Estuarine fish species, Monodactylus falciformis, and two species of the family Mugilidae, Mugil cephalus and Myxus capensis, were the most common fish prey in both size classes of M. salmoides. These results are the first evidence of the alien M. salmoides preying on these three indigenous estuarine species during their migration into fresh water.
- Full Text:
- Date Issued: 2006
- Authors: Weyl, Olaf L F , Lewis, Hylton
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/446852 , vital:74565 , https://doi.org/10.1080/15627020.2006.11407365
- Description: This study presents results from stomach content analysis of 123 largemouth bass, Micropterus salmoides, sampled at the mouth of the fishway leading into a 3 m high weir at the tidal limit of the Kowie River, Eastern Cape Province (33°32‘39“S, 26°46‘ 52.3“E). Stomach contents from small (120–240 mm fork length, FL) and large (250–440mm FL) fish were analysed separately. Fish were the dominant prey item in small bass, followed by terrestrial insects and Potamonautes sp. In large bass, Potamonautes sp. dominated the stomach contents, while fish were less dominant and other prey items were considered incidental. Estuarine fish species, Monodactylus falciformis, and two species of the family Mugilidae, Mugil cephalus and Myxus capensis, were the most common fish prey in both size classes of M. salmoides. These results are the first evidence of the alien M. salmoides preying on these three indigenous estuarine species during their migration into fresh water.
- Full Text:
- Date Issued: 2006
Flexible, High Speed Audio Networking for Hotels and Convention Centres
- Foss, Richard, Fujimori, J I, Chigwamba, Nyasha, Klinkradt, Bradley, Okai-Tettey, Harold
- Authors: Foss, Richard , Fujimori, J I , Chigwamba, Nyasha , Klinkradt, Bradley , Okai-Tettey, Harold
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427292 , vital:72428 , https://www.aes.org/e-lib/browse.cfm?elib=13472
- Description: This paper describes the use of mLAN (music Local Area Network) to solve the problem of audio routing within hotels and convention centers. mLAN is a Firewire based digital network interface technology that allows professional audio equipment, PCs and electronic instruments to be easily and efficiently interconnected using a single cable. In order to solve this problem, an existing mLAN Connection Management Server, augmented with additional functionality, has been utilized. A graphical client application has been created that displays the various locations within a hotel/convention center, and sends out appropriate routing messages in Extensible Mark-up Language (XML) to an mLAN connection management server. The connection management server, in turn, controls a number of mLAN audio distribution boxes on the firewire network.
- Full Text:
- Date Issued: 2006
- Authors: Foss, Richard , Fujimori, J I , Chigwamba, Nyasha , Klinkradt, Bradley , Okai-Tettey, Harold
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/427292 , vital:72428 , https://www.aes.org/e-lib/browse.cfm?elib=13472
- Description: This paper describes the use of mLAN (music Local Area Network) to solve the problem of audio routing within hotels and convention centers. mLAN is a Firewire based digital network interface technology that allows professional audio equipment, PCs and electronic instruments to be easily and efficiently interconnected using a single cable. In order to solve this problem, an existing mLAN Connection Management Server, augmented with additional functionality, has been utilized. A graphical client application has been created that displays the various locations within a hotel/convention center, and sends out appropriate routing messages in Extensible Mark-up Language (XML) to an mLAN connection management server. The connection management server, in turn, controls a number of mLAN audio distribution boxes on the firewire network.
- Full Text:
- Date Issued: 2006
Floral resources of Apis mellifera capensis in the fynbos biome in the Eastern Cape Province, South Africa
- Addi, A, Phillipson, P, Hepburn, H Randall
- Authors: Addi, A , Phillipson, P , Hepburn, H Randall
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451845 , vital:75081 , https://hdl.handle.net/10520/EJC32660
- Description: The plant species utilized by Cape honeybees, Apis mellifera capensis, as primary nectar and pollen sources were studied in the Eastern Cape Province in an area where fynbos vegetation mingles with grassland communities. From direct field observations and analyses of pollen loads collected by foragers, 54 plant species were identified as nectar and pollen sources. Of 37 endemic and exotic pollen source plants, Metalasia muricata, Eucalyptus grandis, E. camadulensis, Erica chamissonis, Helichrysum odoratissimum, H. anomalum, Crassula cultrata and Acacia longifolia were dominant species.
- Full Text:
- Date Issued: 2006
- Authors: Addi, A , Phillipson, P , Hepburn, H Randall
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/451845 , vital:75081 , https://hdl.handle.net/10520/EJC32660
- Description: The plant species utilized by Cape honeybees, Apis mellifera capensis, as primary nectar and pollen sources were studied in the Eastern Cape Province in an area where fynbos vegetation mingles with grassland communities. From direct field observations and analyses of pollen loads collected by foragers, 54 plant species were identified as nectar and pollen sources. Of 37 endemic and exotic pollen source plants, Metalasia muricata, Eucalyptus grandis, E. camadulensis, Erica chamissonis, Helichrysum odoratissimum, H. anomalum, Crassula cultrata and Acacia longifolia were dominant species.
- Full Text:
- Date Issued: 2006
Graph matching with subdivision surfaces for texture synthesis on surfaces
- Bangay, Shaun D, Morkel, Chantelle
- Authors: Bangay, Shaun D , Morkel, Chantelle
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433351 , vital:72964 , https://doi.org/10.1145/1108590.1108601
- Description: Existing texture synthesis-from example strategies for polygon meshes typically make use of three components: a multi-resolution mesh hierarchy that allows the overall nature of the pattern to be reproduced before filling in detail; a matching strategy that extends the synthesized texture using the best fit from a texture sample; and a transfer mechanism that copies the selected portion of the texture sample to the target surface. We introduce novel alternatives for each of these components. Use of √2-subdivision surfaces provides the mesh hierarchy and allows fine control over the surface complexity. Adaptive subdivision is used to create an even vertex distribution over the surface. Use of the graph defined by a surface region for matching, rather than a regular texture neighbourhood, provides for flexible control over the scale of the texture and allows simultaneous matching against multiple levels of an image pyramid created from the texture sample. We use graph cuts for texture transfer, adapting this scheme to the context of surface synthesis. The resulting surface textures are realistic, tolerant of local mesh detail and are comparable to results produced by texture neighbourhood sampling approaches.
- Full Text:
- Date Issued: 2006
- Authors: Bangay, Shaun D , Morkel, Chantelle
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433351 , vital:72964 , https://doi.org/10.1145/1108590.1108601
- Description: Existing texture synthesis-from example strategies for polygon meshes typically make use of three components: a multi-resolution mesh hierarchy that allows the overall nature of the pattern to be reproduced before filling in detail; a matching strategy that extends the synthesized texture using the best fit from a texture sample; and a transfer mechanism that copies the selected portion of the texture sample to the target surface. We introduce novel alternatives for each of these components. Use of √2-subdivision surfaces provides the mesh hierarchy and allows fine control over the surface complexity. Adaptive subdivision is used to create an even vertex distribution over the surface. Use of the graph defined by a surface region for matching, rather than a regular texture neighbourhood, provides for flexible control over the scale of the texture and allows simultaneous matching against multiple levels of an image pyramid created from the texture sample. We use graph cuts for texture transfer, adapting this scheme to the context of surface synthesis. The resulting surface textures are realistic, tolerant of local mesh detail and are comparable to results produced by texture neighbourhood sampling approaches.
- Full Text:
- Date Issued: 2006
Hierarchical rule generalisation for speaker identification in fiction books
- Glass, Kevin R, Bangay, Shaun D
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433174 , vital:72949 , https://doi.org/10.1145/1216262.1216266
- Description: This paper presents a hierarchical pattern matching and generalisation technique which is applied to the problem of locating the correct speaker of quoted speech found in fiction books. Patterns from a training set are generalised to create a small number of rules, which can be used to identify items of interest within the text. The pattern matching technique is applied to finding the Speech-Verb, Actor and Speaker of quotes found in fiction books. The technique performs well over the training data, resulting in rule-sets many times smaller than the training set, but providing very high accuracy. While the rule-set generalised from one book is less effective when applied to different books than an approach based on hand coded heuristics, performance is comparable when testing on data closely related to the training set.
- Full Text:
- Date Issued: 2006
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433174 , vital:72949 , https://doi.org/10.1145/1216262.1216266
- Description: This paper presents a hierarchical pattern matching and generalisation technique which is applied to the problem of locating the correct speaker of quoted speech found in fiction books. Patterns from a training set are generalised to create a small number of rules, which can be used to identify items of interest within the text. The pattern matching technique is applied to finding the Speech-Verb, Actor and Speaker of quotes found in fiction books. The technique performs well over the training data, resulting in rule-sets many times smaller than the training set, but providing very high accuracy. While the rule-set generalised from one book is less effective when applied to different books than an approach based on hand coded heuristics, performance is comparable when testing on data closely related to the training set.
- Full Text:
- Date Issued: 2006
Household fuelwood use in small electrified towns of the Makana District, Eastern Cape, South Africa
- Shackleton, Charlie M, Gambiza, James, Jones, R
- Authors: Shackleton, Charlie M , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182362 , vital:43823 , xlink:href="https://doi.org/10.17159/2413-3051/2007/v18i4a3394"
- Description: Access to secure energy supplies is a key foundation for sustainable development. Consequently local planning and development initiatives must be based on a sound knowledge of the energy use patterns and preferences of local users. This paper reports on such for three small urban settlements in the Eastern Cape Province, with a particular focus on fuelwood use. Despite widespread electrification over a decade ago, and perceptions that the ease of fuelwood collection was declining, most households continued to use fuelwood for cooking and space heating, whereas electricity was favoured for lighting. The most common reason for this was because fuelwood was cheap (or free) compared to electricity. Annual demand was approximately 1 450 kg per household per year. Households that collected their own supplies of fuelwood were significantly poorer than those that either bought their stocks, or those that did not use fuelwood at all. Indigenous species were favoured over exotic species, although fuelwood vendors traded mostly in exotic species, particularly Eucalyptus and wattle. The greater reliance of poorer and unelectrified households on fuelwood requires that local authorities consider this in energy planning, otherwise the poor will be neglected in policies such as the Free Basic Electricity.
- Full Text:
- Date Issued: 2006
Household fuelwood use in small electrified towns of the Makana District, Eastern Cape, South Africa
- Authors: Shackleton, Charlie M , Gambiza, James , Jones, R
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182362 , vital:43823 , xlink:href="https://doi.org/10.17159/2413-3051/2007/v18i4a3394"
- Description: Access to secure energy supplies is a key foundation for sustainable development. Consequently local planning and development initiatives must be based on a sound knowledge of the energy use patterns and preferences of local users. This paper reports on such for three small urban settlements in the Eastern Cape Province, with a particular focus on fuelwood use. Despite widespread electrification over a decade ago, and perceptions that the ease of fuelwood collection was declining, most households continued to use fuelwood for cooking and space heating, whereas electricity was favoured for lighting. The most common reason for this was because fuelwood was cheap (or free) compared to electricity. Annual demand was approximately 1 450 kg per household per year. Households that collected their own supplies of fuelwood were significantly poorer than those that either bought their stocks, or those that did not use fuelwood at all. Indigenous species were favoured over exotic species, although fuelwood vendors traded mostly in exotic species, particularly Eucalyptus and wattle. The greater reliance of poorer and unelectrified households on fuelwood requires that local authorities consider this in energy planning, otherwise the poor will be neglected in policies such as the Free Basic Electricity.
- Full Text:
- Date Issued: 2006
Household wealth status and natural resource use in the Kat River valley, South Africa
- Shackleton, Charlie M, Shackleton, Sheona E
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181301 , vital:43717 , xlink:href="https://doi.org/10.1016/j.ecolecon.2005.04.011"
- Description: Much work has demonstrated the significant role and value of non-timber forest products (NTFPs) in the livelihoods of rural people in southern Africa and elsewhere. The findings provide a mean or composite picture, averaged across the sample households within each community. Yet, within any given community, there is significant socio-economic differentiation. It is important to acknowledge such differentiation when considering policy and management interventions to support rural livelihoods and promote sustainable resource use. This paper reports on a study in South Africa, the objective of which was to explore wealth-related differences and similarities in the use and value of NTFPs. Data on NTFP consumption, purchase, and sale were collected from households in three rural villages. Households were divided into three wealth classes and patterns of NTFPs use between the classes examined. There was no difference in the proportions of households in each wealth class using NTFPs, nor the total number of NTFPs used per household. Yet, there was some supporting evidence that poorer households derive greater benefits from NTFPs than do wealthy or intermediate households. One clear difference was that, with increasing wealth, households purchased significantly more NTFPs, and a greater proportion of wealthy households did so. Conversely, a greater proportion of poor households were involved in the sale of one or more NTFPs, and they sold a greater number per household, compared to wealthy and intermediate households. Detailed examination of use and value of four NTFPs (fuelwood, wild fruits, edible herbs, and grass hand brushes) revealed that in all instances, the poorest households used more of the resource per capita than the other wealth classes. This was not the case for comparisons based on the total household as the unit of analysis. Gross annual direct-use value did not differ between the wealth classes for any of the four NTFPs examined, at the household level. But on a per capita basis, a significantly higher gross annual direct-use value was evident within poorer households for fuelwood and edible herbs. The significance of these differences is discussed.
- Full Text:
- Date Issued: 2006
- Authors: Shackleton, Charlie M , Shackleton, Sheona E
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/181301 , vital:43717 , xlink:href="https://doi.org/10.1016/j.ecolecon.2005.04.011"
- Description: Much work has demonstrated the significant role and value of non-timber forest products (NTFPs) in the livelihoods of rural people in southern Africa and elsewhere. The findings provide a mean or composite picture, averaged across the sample households within each community. Yet, within any given community, there is significant socio-economic differentiation. It is important to acknowledge such differentiation when considering policy and management interventions to support rural livelihoods and promote sustainable resource use. This paper reports on a study in South Africa, the objective of which was to explore wealth-related differences and similarities in the use and value of NTFPs. Data on NTFP consumption, purchase, and sale were collected from households in three rural villages. Households were divided into three wealth classes and patterns of NTFPs use between the classes examined. There was no difference in the proportions of households in each wealth class using NTFPs, nor the total number of NTFPs used per household. Yet, there was some supporting evidence that poorer households derive greater benefits from NTFPs than do wealthy or intermediate households. One clear difference was that, with increasing wealth, households purchased significantly more NTFPs, and a greater proportion of wealthy households did so. Conversely, a greater proportion of poor households were involved in the sale of one or more NTFPs, and they sold a greater number per household, compared to wealthy and intermediate households. Detailed examination of use and value of four NTFPs (fuelwood, wild fruits, edible herbs, and grass hand brushes) revealed that in all instances, the poorest households used more of the resource per capita than the other wealth classes. This was not the case for comparisons based on the total household as the unit of analysis. Gross annual direct-use value did not differ between the wealth classes for any of the four NTFPs examined, at the household level. But on a per capita basis, a significantly higher gross annual direct-use value was evident within poorer households for fuelwood and edible herbs. The significance of these differences is discussed.
- Full Text:
- Date Issued: 2006
Identifying and Investigating Intrusive Scanning Patterns by Visualizing Network Telescope Traffic in a 3-D Scatter-plot
- van Riel, Jean-Pierre, Irwin, Barry V W
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428719 , vital:72531 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfanddoi=aeb0738f0e53a8c9f407fee7e55c852643f2644c
- 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 meth-od. The method entails a combination of network telescope traffic cap-ture and visualisation. Observing traffic from the perspective of a dedi-cated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Compliment-ing this, visual analysis facilitates the rapid review and correlation of events, thereby utilizing human intelligence in the identification of scan-ning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tailor made 3D scatter-plot visualisation. As the results show, the visualisation saliently conveys anomalous patterns, and further analysis reveals that these patterns are indicative of covert network probing activity. By incorporat-ing visual analysis with traditional approaches, such as textual log re-view and the use of an intrusion detection system, this research contrib-utes improved insight into network scanning incidents.
- Full Text:
- Date Issued: 2006
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428719 , vital:72531 , https://citeseerx.ist.psu.edu/document?repid=rep1type=pdfanddoi=aeb0738f0e53a8c9f407fee7e55c852643f2644c
- 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 meth-od. The method entails a combination of network telescope traffic cap-ture and visualisation. Observing traffic from the perspective of a dedi-cated sensor network reduces the volume of data and alleviates the concern of confusing malicious traffic with legitimate traffic. Compliment-ing this, visual analysis facilitates the rapid review and correlation of events, thereby utilizing human intelligence in the identification of scan-ning patterns. To demonstrate the proposed method, several months of network telescope traffic is captured and analysed with a tailor made 3D scatter-plot visualisation. As the results show, the visualisation saliently conveys anomalous patterns, and further analysis reveals that these patterns are indicative of covert network probing activity. By incorporat-ing visual analysis with traditional approaches, such as textual log re-view and the use of an intrusion detection system, this research contrib-utes improved insight into network scanning incidents.
- Full Text:
- Date Issued: 2006
Identifying needs and opportunities for local government environmental education and training in South Africa
- Olvitt, Lausanne L, Hamaamba, Tyson
- Authors: Olvitt, Lausanne L , Hamaamba, Tyson
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370991 , vital:66400 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122739"
- Description: Effective environmental management and public engagement with environmental concerns are needed for the attainment of sustainable development goals and socio-ecological balance in local government contexts. This vision is clearly articulated in international environmental policy frameworks and in South Africa’s national and regional legislation. However, policy and legislation fall short of identifying the range of a priori competences required by local government officials and environmental managers before well intended policy can be translated into effective practice. This paper reports on recent research into identifying the underlying competences required for better environmental management and the establishment of education and training processes for local government managers. The research draws on the notion of ‘applied competence’ put forward by South Africa’s National Qualifications Framework, and argues that greater attention needs to be paid to competence-based capacity building processes within local government departments if environmental sustainability and development goals are to be met. The paper draws on the researchers’ experiences of formulating a national level generic competence framework for environmental management, and conducting an education and training needs analysis for the Makana Municipality in the Eastern Cape province of South Africa. Early findings suggest that a broad range of competences all have a role in ensuring the capacity and effectiveness of local governments to better manage their local environment. The paper argues that these are significant for the development of environmental education and training programmes in local government contexts.
- Full Text:
- Date Issued: 2006
- Authors: Olvitt, Lausanne L , Hamaamba, Tyson
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/370991 , vital:66400 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122739"
- Description: Effective environmental management and public engagement with environmental concerns are needed for the attainment of sustainable development goals and socio-ecological balance in local government contexts. This vision is clearly articulated in international environmental policy frameworks and in South Africa’s national and regional legislation. However, policy and legislation fall short of identifying the range of a priori competences required by local government officials and environmental managers before well intended policy can be translated into effective practice. This paper reports on recent research into identifying the underlying competences required for better environmental management and the establishment of education and training processes for local government managers. The research draws on the notion of ‘applied competence’ put forward by South Africa’s National Qualifications Framework, and argues that greater attention needs to be paid to competence-based capacity building processes within local government departments if environmental sustainability and development goals are to be met. The paper draws on the researchers’ experiences of formulating a national level generic competence framework for environmental management, and conducting an education and training needs analysis for the Makana Municipality in the Eastern Cape province of South Africa. Early findings suggest that a broad range of competences all have a role in ensuring the capacity and effectiveness of local governments to better manage their local environment. The paper argues that these are significant for the development of environmental education and training programmes in local government contexts.
- Full Text:
- Date Issued: 2006
Implementing the GrabCut segmentation technique as a plugin for the GIMP
- Marsh, Matthew, Bangay, Shaun D, Lobb, Adele
- Authors: Marsh, Matthew , Bangay, Shaun D , Lobb, Adele
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433207 , vital:72951 , https://doi.org/10.1145/1108590.1108618
- Description: Image segmentation requires a segmentation tool that is fast and easy to use. The GIMP has built in segmentation tools, but under some circumstances these tools perform badly. "GrabCut" is an innovative segmentation technique that uses both region and boundary information in order to perform segmentation. Several variations on the "GrabCut" algorithm have been implemented as a plugin for the GIMP. The results obtained using "GrabCut" are comparable, and often better than the results of all the other built in segmentation tools.
- Full Text:
- Date Issued: 2006
- Authors: Marsh, Matthew , Bangay, Shaun D , Lobb, Adele
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433207 , vital:72951 , https://doi.org/10.1145/1108590.1108618
- Description: Image segmentation requires a segmentation tool that is fast and easy to use. The GIMP has built in segmentation tools, but under some circumstances these tools perform badly. "GrabCut" is an innovative segmentation technique that uses both region and boundary information in order to perform segmentation. Several variations on the "GrabCut" algorithm have been implemented as a plugin for the GIMP. The results obtained using "GrabCut" are comparable, and often better than the results of all the other built in segmentation tools.
- Full Text:
- Date Issued: 2006
Incorporating fishermen’s local knowledge and behavior into geographical information systems (GIS) for designing marine protected areas in Oceania
- Shankar, Aswani, Lauer, Matthew
- Authors: Shankar, Aswani , Lauer, Matthew
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439109 , vital:73545 , xlink:href="https://doi.org/10.17730/humo.65.1.4y2q0vhe4l30n0uj"
- Description: Drawing on our experience in establishing marine protected areas (MPAs) in the Roviana and Vonavona Lagoons, New Georgia, Solomon Islands, this paper shows how a geographical information system (GIS) database can be used to incorporate sociospatial information, such as indigenous knowledge and artisanal fishing data, along with biophysical and other information to assist in MPA design. We argue that converting peoples’ knowledge and socioecological behavior into geo-spatial data allows researchers to formulate hypotheses regarding human responses to inter- and intra-habitat variability, along with other marine ecological processes, and help in the designing and implementation of resource management strategies in a cost-effective and participatory way, bridging the gap between indigenous and Western cognitions of seascapes. More generally, we show the significance of combining spatial tools, anthropological fieldwork, and social and natural science methods for studying artisanal fisheries with the goal of aiding the design of marine protected areas.
- Full Text:
- Date Issued: 2006
- Authors: Shankar, Aswani , Lauer, Matthew
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/439109 , vital:73545 , xlink:href="https://doi.org/10.17730/humo.65.1.4y2q0vhe4l30n0uj"
- Description: Drawing on our experience in establishing marine protected areas (MPAs) in the Roviana and Vonavona Lagoons, New Georgia, Solomon Islands, this paper shows how a geographical information system (GIS) database can be used to incorporate sociospatial information, such as indigenous knowledge and artisanal fishing data, along with biophysical and other information to assist in MPA design. We argue that converting peoples’ knowledge and socioecological behavior into geo-spatial data allows researchers to formulate hypotheses regarding human responses to inter- and intra-habitat variability, along with other marine ecological processes, and help in the designing and implementation of resource management strategies in a cost-effective and participatory way, bridging the gap between indigenous and Western cognitions of seascapes. More generally, we show the significance of combining spatial tools, anthropological fieldwork, and social and natural science methods for studying artisanal fisheries with the goal of aiding the design of marine protected areas.
- Full Text:
- Date Issued: 2006
Indigenous languages and the media in South Africa:
- Authors: Kaschula, Russell H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175137 , vital:42546 , https://hdl.handle.net/10520/EJC15168
- Description: This article explores the status of South Africa’s indigenous languages and how they are being used in the media. More specifically, the performance of these languages in the print media, the broadcasting media and the Internet, is outlined. This is done against the backdrop of the South African Constitution, Section 6, which entrenches eleven official languages. Contrary to the Constitution’s provisions, it is found that the indigenous languages are achieving varying levels of success within the media. The reasons for this are outlined. Finally, the effects of globalisation on the indigenous languages within the media are assessed.
- Full Text:
- Date Issued: 2006
- Authors: Kaschula, Russell H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/175137 , vital:42546 , https://hdl.handle.net/10520/EJC15168
- Description: This article explores the status of South Africa’s indigenous languages and how they are being used in the media. More specifically, the performance of these languages in the print media, the broadcasting media and the Internet, is outlined. This is done against the backdrop of the South African Constitution, Section 6, which entrenches eleven official languages. Contrary to the Constitution’s provisions, it is found that the indigenous languages are achieving varying levels of success within the media. The reasons for this are outlined. Finally, the effects of globalisation on the indigenous languages within the media are assessed.
- Full Text:
- Date Issued: 2006
Inetvis, a visual tool for network telescope traffic analysis
- van Riel, Jean-Pierre, Irwin, Barry V W
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430176 , vital:72671 , https://doi.org/10.1145/1108590.1108604
- Description: This article illustrates the merits of visual analysis as it presents prelimi-nary findings using InetVis - an animated 3-D scatter plot visualization of network events. The concepts and features of InetVis are evaluated with reference to related work in the field. Tested against a network scanning tool, anticipated visual signs of port scanning and network mapping serve as a proof of concept. This research also unveils sub-stantial amounts of suspicious activity present in Internet traffic during August 2005, as captured by a class C network telescope. InetVis is found to have promising scalability whilst offering salient depictions of intrusive network activity.
- Full Text:
- Date Issued: 2006
- Authors: van Riel, Jean-Pierre , Irwin, Barry V W
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/430176 , vital:72671 , https://doi.org/10.1145/1108590.1108604
- Description: This article illustrates the merits of visual analysis as it presents prelimi-nary findings using InetVis - an animated 3-D scatter plot visualization of network events. The concepts and features of InetVis are evaluated with reference to related work in the field. Tested against a network scanning tool, anticipated visual signs of port scanning and network mapping serve as a proof of concept. This research also unveils sub-stantial amounts of suspicious activity present in Internet traffic during August 2005, as captured by a class C network telescope. InetVis is found to have promising scalability whilst offering salient depictions of intrusive network activity.
- Full Text:
- Date Issued: 2006
Integrating Secure RTP into the Open Source VoIP PBX Asterisk
- Clayton, Bradley, Irwin, Barry V W, Terzoli, Alfredo
- Authors: Clayton, Bradley , Irwin, Barry V W , Terzoli, Alfredo
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428735 , vital:72532 , https://d1wqtxts1xzle7.cloudfront.net/84872934/66_Paper-libre.pdf?1650920302=response-content-disposi-tion=inline%3B+filename%3DIntegrating_Secure_RTP_into_the_Open_Sou.pdfExpires=1714744382Signature=PijjCGW0qcvkqRe-2R55HocKLvz9Ljw8jmhQvRQEi9YqJl7eWSiYnvs9CogY4u4bmDTYTLpvkA-nlfbiszg-s7Cq2nbLn3PUdfJ5cA11ujboi~i7oSoem7smuN1YCVZlg7FnZRd6mOXdTry9UAh8TlWyndF6pY1RXtc7bgb5cWeK4ggJ7~bM0HUXEbUKKa-abCZnGNrAZ59JIdL6CNx1Sht3o5mZTcyRL3PNVSOz17lldXi4FsAOEUwsVV-uv04hzp6pe6Qv5WbAP6tqk7deyoLUwk58A9F-PaJlOLy2gDAVLnbKT8RrxYg8tqv8SuBhPWb32CefBxv486N3F6izZw__Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Implementations of Voice over Internet Protocol (VoIP) have focused, up to now, mainly on the need to transport data in real-time, often at the expense of security. The neglect of secure VoIP is often intentional, as developers are striving to minimise overheads and delays. The Secure Real-Time Protocol (SRTP) has the potential to secure real-time streams without exacting too high a performance price. SRTP is the addition of security to the audio/video profile used in the Real-Time Transport Protocol (RTP). SRTP adds confidentiality, integrity and op-tionaly authenticity to RTP media streams. This paper focuses on the integration of SRTP into Asterisk, an open-source VoIP PBX. SRTP support has recently been added to Asterisk by Mikael Magnusson. This paper analyses Magnusson’s implementation, contrasting it to a proof-of-concept implementation developed independently at Rhodes University. The interoperability of SRTP implementations cannot be taken for granted, given the relatively recent standardization of the pro-tocol, and so Magnusson’s implementation is tested against another SRTP implementation. Finally, the paper highlights a major shortcoming in Magnusson’s implementation, namely that the exchange of encryp-tion keys is done in the clear. It concludes by proposing possible solu-tions, such as TLS, IPSec and MIkey.
- Full Text:
- Date Issued: 2006
- Authors: Clayton, Bradley , Irwin, Barry V W , Terzoli, Alfredo
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428735 , vital:72532 , https://d1wqtxts1xzle7.cloudfront.net/84872934/66_Paper-libre.pdf?1650920302=response-content-disposi-tion=inline%3B+filename%3DIntegrating_Secure_RTP_into_the_Open_Sou.pdfExpires=1714744382Signature=PijjCGW0qcvkqRe-2R55HocKLvz9Ljw8jmhQvRQEi9YqJl7eWSiYnvs9CogY4u4bmDTYTLpvkA-nlfbiszg-s7Cq2nbLn3PUdfJ5cA11ujboi~i7oSoem7smuN1YCVZlg7FnZRd6mOXdTry9UAh8TlWyndF6pY1RXtc7bgb5cWeK4ggJ7~bM0HUXEbUKKa-abCZnGNrAZ59JIdL6CNx1Sht3o5mZTcyRL3PNVSOz17lldXi4FsAOEUwsVV-uv04hzp6pe6Qv5WbAP6tqk7deyoLUwk58A9F-PaJlOLy2gDAVLnbKT8RrxYg8tqv8SuBhPWb32CefBxv486N3F6izZw__Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Implementations of Voice over Internet Protocol (VoIP) have focused, up to now, mainly on the need to transport data in real-time, often at the expense of security. The neglect of secure VoIP is often intentional, as developers are striving to minimise overheads and delays. The Secure Real-Time Protocol (SRTP) has the potential to secure real-time streams without exacting too high a performance price. SRTP is the addition of security to the audio/video profile used in the Real-Time Transport Protocol (RTP). SRTP adds confidentiality, integrity and op-tionaly authenticity to RTP media streams. This paper focuses on the integration of SRTP into Asterisk, an open-source VoIP PBX. SRTP support has recently been added to Asterisk by Mikael Magnusson. This paper analyses Magnusson’s implementation, contrasting it to a proof-of-concept implementation developed independently at Rhodes University. The interoperability of SRTP implementations cannot be taken for granted, given the relatively recent standardization of the pro-tocol, and so Magnusson’s implementation is tested against another SRTP implementation. Finally, the paper highlights a major shortcoming in Magnusson’s implementation, namely that the exchange of encryp-tion keys is done in the clear. It concludes by proposing possible solu-tions, such as TLS, IPSec and MIkey.
- Full Text:
- Date Issued: 2006
Is economic impact a good way of justifying the inclusion of foreign students at local universities?
- Snowball, Jeanette D, Antrobus, Geoffrey G
- Authors: Snowball, Jeanette D , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67470 , vital:29098 , http://dx.doi.org/10.4314/sajhe.v20i3.25593
- Description: Pre-print , In the debate surrounding the costs and benefits of having foreign students at South African universities, the financial contributions of foreign students to their host economies is sometimes cited. This article reports the results of a comparison between the economic impact on the Grahamstown economy of the spending of foreign and local students at Rhodes University. It finds that the spending patterns of both types of students are remarkably similar and that the somewhat higher economic impact of foreign students is largely as a result of their propensity to choose the more expensive residence accommodation, rather than as a result of greater average spending generally. We suggest that economic impact studies should be used with caution when making the case for continued public subsidy of goods with significant non-market values and that opportunity costs should also be considered.
- Full Text:
- Date Issued: 2006
Is economic impact a good way of justifying the inclusion of foreign students at local universities?
- Authors: Snowball, Jeanette D , Antrobus, Geoffrey G
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67470 , vital:29098 , http://dx.doi.org/10.4314/sajhe.v20i3.25593
- Description: Pre-print , In the debate surrounding the costs and benefits of having foreign students at South African universities, the financial contributions of foreign students to their host economies is sometimes cited. This article reports the results of a comparison between the economic impact on the Grahamstown economy of the spending of foreign and local students at Rhodes University. It finds that the spending patterns of both types of students are remarkably similar and that the somewhat higher economic impact of foreign students is largely as a result of their propensity to choose the more expensive residence accommodation, rather than as a result of greater average spending generally. We suggest that economic impact studies should be used with caution when making the case for continued public subsidy of goods with significant non-market values and that opportunity costs should also be considered.
- Full Text:
- Date Issued: 2006
Izaci namaqhalo esiXhosa: Xhosa idioms and proverbs referring to plants
- Cocks, Michelle L, Dold, Anthony P
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141326 , vital:37962 , https://hdl.handle.net/10520/EJC112940
- Description: Converging with the ecological extinction crisis, the planet has been experiencing a severe erosion of the diversity of human cultures and languages, reducing the pool of knowledge, behaviors and values from which individual communities and humanity at large can draw to respond to social and environmental stresses.
- Full Text:
- Date Issued: 2006
- Authors: Cocks, Michelle L , Dold, Anthony P
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/141326 , vital:37962 , https://hdl.handle.net/10520/EJC112940
- Description: Converging with the ecological extinction crisis, the planet has been experiencing a severe erosion of the diversity of human cultures and languages, reducing the pool of knowledge, behaviors and values from which individual communities and humanity at large can draw to respond to social and environmental stresses.
- Full Text:
- Date Issued: 2006