Spatial and seasonal distribution patterns of juvenile and adult raggedtooth sharks (Carcharias taurus) tagged off the east coast of South Africa
- Authors: Dicken, Matthew L , Booth, Anthony J , Smale, Malcolm J , Cliff, G
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/126997 , vital:35942 , https://doi.10.1071/MF06018
- Description: Crucial to effective fisheries management is a thorough understanding of the stock structure of a population. Understanding the spatial and seasonal distribution patterns of a species is necessary to define habitat use and evaluate the potential effects of exploitation and anthropogenic activities. This is particularly important for a species such as the raggedtooth shark (Carcharias Taurus Rafinesque, 1810), whose life-history characteristics make it particularly susceptible to over-exploitation (Pollard et al. 1996; Smith et al. 1998; Compagno 2001). Exploitation, even at low levels for a slow-growing, late-maturing species that only produces two pups every other year, could reduce the population growth rate, could reduce the population growth rate to values of λ<1.0, resulting in severe population declines in a very short time period (Baum et al. 2003).
- Full Text:
- Date Issued: 2007
Submerged membrane bioreactor and secondary digestion for the treatment of wine distillery wastewater: Part I: Raw wine distillery wastewater digestion
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/76139 , vital:30511 , https://www.prt-parlar.de/download_feb_2007/
- Description: A combination of a submerged membrane bioreactor (SMBR) and a secondary digester was tested for the treatment of wine distillery wastewater (WDW). The experimental system, consisting of four individual reactors, was tested during a 30-days study. Buffering of pH was achieved by mixing the feed stream of the system with 1000 mg/l of CaCO3 and K2HPO4 for the initial 10 days of the bioreactor system operation, and with 8000 mg/l of CaCO3 and 4000 mg/l of K2HPO4 for the remainder of the study. Buffering proved to be significant for optimum performance of the system in removal of soluble chemical oxygen demand (CODS), and volatile fatty acids (VFAs). Different batches of WDW used for feeding the reactor had variable compositions with respect to concentrations of nitrates, ammonium and the total concentration of phenolic compounds. Am-monium accumulated in the secondary digester after 14 days of treatment system operation, indicating the time required for the establishment of anaerobic conditions in the system. An additional step would be required for removal of phosphates from the effluent of the bioreactor, e.g., reverse osmosis, if the effluent is to be reused in production or other applications.
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- Date Issued: 2007
The need for an inland fisheries policy in South Africa : a case study of the North West Province
- Authors: Weyl, Olaf L F , Potts, Warren M , Rouhani, Q
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6769 , http://hdl.handle.net/10962/d1008056
- Description: In contrast to many other African countries, inland fisheries in South Africa are poorly developed and the fish populations in many of the country’s 3 000 major dams are under-utilised. While the primary purpose South Africa’s dams is to supply water for domestic and agricultural use, there has been an increasing realisation that their fish populations could make a contribution to food security through the establishment of capture fisheries. Historically, the fish in most South African dams have primarily been utilised for recreational fishing purposes, as subsistence use was criminalised by the apartheid regime in all waters except in the former homeland areas. This legacy persists as many of South Africa’s rural communities do not have a fishing tradition and there is a lack of an institutional framework to facilitate managed and sustainable access to the fish resource in inland waters. Current utilisation of many inland dams is often complicated by the existence of multiple authorities and interest groups, often with competing agendas. As a result, the economic potential of these water bodies is unknown and often grossly underutilised. Our study outlines a case study of fisheries resources in the North West Province of South Africa that could be used for the creation of income and food security for local communities through the development of subsistence, commercial, and recreational fisheries. The study identifies the lack of guidelines for the development of inland fisheries and the lack of an inland fisheries policy, both at the provincial and national level, as major bottlenecks for the sustainable development of these resources and outlines possible focal areas for intervention.
- Full Text:
- Date Issued: 2007
Treatment of wine distillery wastewater by high rate anaerobic digestion
- Authors: Melamane, Xolisa L , Tandlich, Roman , Burgess, Jo E
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/75896 , vital:30480 , https://doi.org/10.2166/wst.2007.466
- Description: Wine distillery wastewaters (WDW) are acidic and have a high content of potential organic pollutants. This causes high chemical oxygen demand (COD) values. Polyphenols constitute a significant portion of this COD, and limit the efficiency of biological treatment of WDWs. WDW starting parameters were as follows: pH 3.83, 4,185 mg/l soluble COD (CODs) and 674.6 mg/l of phenols. During operation, amendments of CaCO3 and K2HPO4, individually or in combination, were required for buffering the digester.
- Full Text: false
- Date Issued: 2007
A technique for evaluating species richness maps generated from collections data
- Authors: Robertson, Mark P , Barker, Nigel P
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6538 , http://hdl.handle.net/10962/d1005979
- Description: There is considerable pressure on conservation planners to use existing data from herbarium and museum collections for planning and monitoring, despite the weaknesses of such data. It is thus important to be able to assess the quality of this information. One application of these data is the production of species richness maps. However, sampling effort is generally not consistent throughout a region for maps generated from collections data, and it is thus desirable to identify geographic grid cells (such as quarter degree squares: QDS) for which there has been low sampling effort. We describe a technique that can be used to identify QDS that are likely to have low species richness that is due to insufficient sampling effort rather than to low actual species richness. The technique exploits relationships between climate and species richness to detect QDS that are poorly sampled. This approach offers advantages over the current practice of applying a single threshold across the entire map region to detectQDSthat are poorly sampled. Here we report on the application of our technique to plant species richness data in the PRECIS database. Results reveal that the majority of QDS in the Flora of Southern Africa region can be considered to be poorly sampled, even when using conservative thresholds for richness values. The advantages and weaknesses of the technique are discussed and issues requiring further investigation are highlighted.
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- Date Issued: 2006
Cognitive pharmaceutical services and the community pharmacist: are South African patients receiving them and are they willing to pay?
- Authors: Hill, Peter W , Dowse, Roslind
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/156829 , vital:40054 , DOI 10.1211/ijpp.15.2.0007
- Description: The objectives of this study were to ascertain the opinions of randomly selected South African medical aid members regarding the provision by community pharmacists of patient counselling and information; member satisfaction with pharmacist services; their rating of pharmacist accessibility; and if pharmacists should be reimbursed for providing cognitive pharmaceutical services. Setting A South African private healthcare insurance company.
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- Date Issued: 2006
Duplicating road patterns in south african informal settlements using procedural techniques
- Authors: Glass, Kevin R , Morkel, Chantelle , Bangay, Shaun D
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432875 , vital:72909 , https://doi.org/10.1145/1108590.1108616
- Description: The formation of informal settlements in and around urban complexes has largely been ignored in the context of procedural city modeling. However, many cities in South Africa and globally can attest to the presence of such settlements. This paper analyses the phenomenon of informal settlements from a procedural modeling perspective. Aerial photography from two South African urban complexes, namely Johannesburg and Cape Town is used as a basis for the extraction of various features that distinguish different types of settlements. In particular, the road patterns which have formed within such settlements are analysed, and various procedural techniques proposed (including Voronoi diagrams, subdivision and L-systems) to replicate the identified features. A qualitative assessment of the procedural techniques is provided, and the most suitable combination of techniques identified for unstructured and structured settlements. In particular it is found that a combination of Voronoi diagrams and subdivision provides the closest match to unstructured informal settlements. A combination of L-systems, Voronoi diagrams and subdivision is found to produce the closest pattern to a structured informal settlement.
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- Date Issued: 2006
Evaluation of kinetic parameters of traps in thermoluminescence phosphors
- Authors: Ogundare, F O , Balogun, F A , Hussain, L
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6798 , http://hdl.handle.net/10962/d1003924 , http://dx.doi.org/10.1016/j.radmeas.2006.06.014
- Description: A method for evaluating trap depth E, order of kinetics b and frequency factor s from a thermoluminescence (TL) glow peak has been developed. The method is based on using intensities and temperatures at any three points on the glow peak. Unlike similar techniques that provide no expression for frequency factor, the present formulation provides such an expression. The expression does not require knowledge of the temperature at which maximum intensity occurs, a parameter not usually known accurately from experimental glow peak data. For the method, it is found that use of points in the ascending part of the glow peak where the intensities are less than 10% maximum intensity gives parameter values closest to the true ones. Possible reasons for getting less accurate results when points are taken beyond this region are discussed. Values of the activation energy calculated using the present technique were always close to the true value. However, the frequency factor only approaches the true value as the dose given to the sample approaches saturation. When the three data points are selected in the initial-rise region, the equation for evaluating E in the method described in this paper becomes a two-point version of the initial-rise method. The advantage of the present technique over the initial-rise method is that it also gives b and hence s. The method is used to analyse the TL glow curve of a gamma-irradiated sample from Ijero-Ekiti, Nigeria.
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- Date Issued: 2006
Grahamstown film and heritage as reflected by His Majesty's building
- Authors: Still-Drewett, F
- Date: 2006
- Language: English
- Type: Text
- Identifier: vital:6981 , http://hdl.handle.net/10962/d1012409
- Description: Grahamstown Film and Heritage as reflected by His Majesty's Building. The building of His Majesty's theatre has had and continues to have an influential and varied history in the town of Grahamstown. The heritage of the building is linked both to its historical purpose and role in the community, and with the imposing architectural features and central locality. In this oral history project HMT became a vehicle for researching broader issues. The following issues arose: the effects of apartheid policy in entertainment areas; the arrival of national franchises and resultant tensions of preservation of building and cultural heritage versus economic development; the impact of new media such as TV and Video on the cinema theatre; and the community Fruit & Veg 'Colour' dispute. Four key informants were selected and 5 oral history interviews conducted in May 2006. The history of the theatre, film and entertainment memoirs, social comment, and a life history were recorded. , The oral history project pertaining to this paper is housed at the Cory Library, Rhodes University. See also Oral History Association of South Africa: http://www.ohasa.org.za/
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- Date Issued: 2006
Managing South Africa's trawl bycatch
- Authors: Walmsley, Sarah A , Leslie, Rob W , Sauer, Warwick H H
- Date: 2006
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124954 , vital:35713 , https://doi.10.1093/icesjms/fsl022
- Description: Over the past few decades, it has become widely recognized that the management strategies of world fisheries must ensure sustainability of bycatch as well as of target species. South Africa implemented a pilot observer programme from 1995 to 2000 to collect data on the levels and patterns of bycatch and discards in the demersal trawl fishery. Here, the results of that programme are used in conjunction with information on bycatch value and compliance to assess the issues and problems regarding bycatch and discarding in the fishery. In general, bycatch components can be placed into one of three categories (discarded bycatch, retained bycatch, and processing waste), each of which present different management problems and require different management approaches. The results were used to formulate a bycatch management plan for the demersal trawl fishery in South Africa. Given the need to continue monitoring bycatch, the performance of the pilot observer programme is reviewed, and the levels of sampling effort required for a national programme are discussed.
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- Date Issued: 2006
Nestmate recognition and genetic variability among individuals from nests of the queenless ponerine ant, Streblognathus aethiopicus Smith (Hymenoptera: Formicidae)
- Authors: Schluns, E A , Neumann, Peter , Schluns, H , Hepburn, H Randall , Moritz, Robin F A
- Date: 2006
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/452000 , vital:75094 , https://hdl.handle.net/10520/EJC32667
- Description: Nestmate recognition in the queenless ponerine ant, Streblognathus aethiopicus, was evaluated with a behavioural bioassay. Ten pairs of nests were randomly chosen from an aggregation of 74 nests. While nestmates never showed aggression towards each other, the behaviour towards non-nestmates was either aggressive or non-aggressive, demonstrating the ability to recognize nestmates. Also, the nests in this aggregation were evenly spaced, further supporting the notion of territoriality in this species. To evaluate the relative importance of environment and genetics on the observed variation in nestmate recognition, we measured the spatial and genetic distances between nests. Workers of 13 nests were genotyped with the AFLP technique. Multiple regression analysis revealed no significant impact of spatial and genetic distance on aggressive behaviour. Thus, further studies are necessary to reveal the actual mechanisms underlying nestmate recognition in this species. Two distinct groups of nests with genetically homogeneous and heterogeneous workers were found, which may indicate gamergate replacement or colony fission.
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- Date Issued: 2006
Review of the African distribution of the brine shrimp genus Artemia
- Authors: Kaiser, Horst , Gordon, Andrew K , Paulet, T G
- Date: 2006
- Language: English
- Type: Article
- Identifier: vital:6765 , http://hdl.handle.net/10962/d1007963
- Description: Brine shrimp (genus Artemia) are small (8 to 12 mm long) cosmopolitan crustaceans (Anostraca) found predominately in hypersaline water bodies such as inland salt lakes and pans, coastal lagoons, and salt works at salinity levels above 40 g(.)l[superscript(-1)]. They have been extensively studied due to their high monetary value as food for larval fish in aquaculture and their unique reproductive strategies. Brine shrimp occur as either bisexual species or as parthenogenetic populations. Despite published reviews of their world-wide distribution little is known about their occurrence in Africa. This review adds new information about 70 African Artemia sites and lists 26 potential sites and their coordinates. Sixteen sites in Southern Africa and Namibia were visited during a collecting trip, and new information on the reproductive mode of nine of these sites is given. Several South African populations exhibit bisexual reproduction. In Namibia there are two parthenogenetic populations (Walvis Bay and Swartkops) and an additional bisexual population (Hentie's Bay). A mixed population (bisexual and parthenogenetic reproduction at the same site) was found at Coega, South Africa.
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- Date Issued: 2006
Sidelining developmental goals? Re-imaging Port Elizabeth for the 2010 Soccer World Cup
- Authors: Baines, Gary F
- Date: 2006
- Language: English
- Type: Conference paper
- Identifier: vital:6155 , http://hdl.handle.net/10962/d1007070
- Full Text:
- Date Issued: 2006
Wireless Security Tools
- 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.
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- Date Issued: 2006
Burrow utilization by springhares (Pedetes capensis) in the Eastern Cape, South Africa
- Authors: Peinke, Dean , Brown, C R
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447073 , vital:74582 , https://doi.org/10.1080/15627020.2005.11407307
- Description: The use of burrows by springhares was investigated in the Eastern Cape, South Africa using radio telemetry. Springhares utilized 4–27 different burrows scattered over areas ranging from 0.6–28.5 ha, with maximum distances of 170–1000 m between burrows. Springhares frequently changed burrows, seldom spending more than a few consecutive days in each, unless rearing young. The number of burrows used by individuals was correlated with the length of time they were tracked and, even after a year, some individuals were still occupying burrows previously unused by them. Males and females did not differ significantly in the mean number of burrows used, the mean area over which these were distributed, or the mean maximum distance between burrows. Springhares were generally solitary and occupied burrows were, with few exceptions, apparently avoided by conspecifics.
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- Date Issued: 2005
Critical perspectives on research on post-traumatic stress disorder and implications for the South African context
- Authors: Edwards, David J A
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6228 , http://hdl.handle.net/10962/d1007778
- Description: This article introduces a special issue of the Journal of Psychology in Africa on post-traumatic stress disorder (PTSD) in Africa and particularly in South Africa and examines the critical debate that has surrounded PTSD research. It begins with an examination of the meaning of the term trauma, and of its specialised use within the clinical context and with respect to the concept of PTSD. The diagnostic approach to the detection of PTSD is presented, criteria in the DSM-IV-TR and the ICD-10 are summarised and differences between the two manuals are discussed. Arguments presented by critics of the concept of PTSD are presented and discussed. These concern the historical evolution of the concept, concerns about the universality of PTSD cross-culturally, and problems arising from understanding human suffering from a narrow medical perspective. It is concluded that while there are dangers in thinking of the sequelae of trauma as a medical/psychiatric problem, and while the alarming rate of traumatic events needs to be addressed at the political, economic and societal level, there is an important place for the provision of assessment and treatment of PTSD within a psychiatric/psychological clinical setting.
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- Date Issued: 2005
Evaluating parts-of-speech taggers for use in a text-to-scene conversion system
- Authors: Glass, Kevin R , Bangay, Shaun D
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/432654 , vital:72890 , https://www.cs.ru.ac.za/research/groups/vrsig/currentprojects/053texttoscene/paper01.pdf
- Description: This paper presents parts-of-speech tagging as a first step towards an autonomous text-to-scene conversion system. It categorizes some freely available taggers, according to the techniques used by each in order to automatically identify word-classes. In addition, the performance of each identified tagger is verified experimentally. The SUSANNE corpus is used for testing and reveals the complexity of working with different tagsets, resulting in substantially lower accuracies in our tests than in those reported by the developers of each tagger. The taggers are then grouped to form a voting system to attempt to raise accuracies, but in no cases do the combined results improve upon the individual accuracies. Additionally a new metric, agreement, is tentatively proposed as an indication of confidence in the output of a group of taggers where such output cannot be validated.
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- Date Issued: 2005
From trauma debriefing to trauma support: a South African experience of responding to individuals and communities in the aftermath of traumatising events
- Authors: Van Wyk, G , Edwards, David J A
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6267 , http://hdl.handle.net/10962/d1008266
- Description: This paper documents the approach and experience of Traumaclinic, a Cape Town based organisation offering a trauma support service. The controversy over single session debriefing interventions is examined and it is concluded that interventions that invite intense emotional expression should not be offered indiscriminately or forced on those who do not want them. When they do occur, they need to be carefully managed and take place over several sessions. A review of contemporary approaches to intervention following trauma highlights their comprehensive and flexible nature and the inclusion of multiple components that are introduced in a manner responsive to the needs of the situation. This is the basis of the current model used by Traumaclinic. The principles of that model are summarised and examples given of the application of the approach to specific cases.
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- Date Issued: 2005
Life history of the springhare (Pedetes capensis) from a strongly seasonal environment in the Eastern Cape Province of South Africa
- Authors: Peinke, Dean , Bernard, Ric T F
- Date: 2005
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/447089 , vital:74583 , doi.org/10.1080/15627020.2005.11407327
- Description: The life history of the springhare (Pedetes capensis, Forster, 1778) at 33°S, in the Eastern Cape Province of South Africa, was characterized by continuous, aseasonal and asynchronous reproduction. Females were monotocous and consecutive pregnancies were separated by a non pregnant period (30–50 days) similar in length to the period of lactation. Young were relatively large at birth (8% of adult body weight) but were altricial and only emerged from the burrow at weaning. Towards the end of lactation, many females mated again (20% of all females were both lactating and in early pregnancy) and annual fecundity was probably two but never more than three. For a rodent, albeit a large one, this is a very slow rate of reproduction and we propose that the ricochetal locomotion (jumping on the hind legs) and semi-fossorial life style of the springhare will have resulted in decreased juvenile and adult mortality, and increased longevity, and that these factors have shaped the evolution of the life history of the springhare.
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- Date Issued: 2005
Psychotherapy for post-traumatic stress disorder in a young rape survivor: a case study
- Authors: Labe, Dana
- Date: 2005
- Language: English
- Type: Article
- Identifier: vital:6271 , http://hdl.handle.net/10962/d1008271
- Description: This paper describes the psychodynamic psychotherapy of a 20-year-old African woman with post-traumatic stress disorder (PTSD). ‘Mphumi’ entered therapy a year after her father’s friend had repeatedly raped her. The paper documents the process of therapy and uses the case material to examine theoretical issues relevant to the treatment of PTSD. First, Horowitz’s (2001) theory is used as a basis for arguing that a histrionic personality style predisposed her to an extreme degree of denial and dissociation, which prevented her from processing the trauma at a cognitive or emotional level and contributed to the entrenched PTSD. It was only after she had suffered a breakdown, which necessitated hospitalisation, that her resistance to processing the trauma was overcome. Second, the case material is used to show how other significantly disturbing events earlier in her life shaped her response to the rape and to examine the extent to which effective processing of the current trauma calls for the acknowledgement and working through of earlier traumas and losses. Finally, the case narrative shows how the treatment of PTSD is of necessity a slow, complex process which takes into account the individual’s unique history, idiosyncratic vulnerabilities and socio-cultural context
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- Date Issued: 2005