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OseGoli makabuye

- Preformer not specified, Composer not specified, Dargie, Dave

Perceptions relating to students performance in small business management at further education and training colleges

- Kiewiets, Winifred Margaret

  • Authors: Kiewiets, Winifred Margaret
  • Date: 2005
  • Subjects: Small business -- Management -- Study and teaching -- South Africa , College teachers -- South Africa -- Attitudes , College students -- Rating of -- South Africa , College students -- South Africa -- Attitudes
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:9558 , http://hdl.handle.net/10948/463 , http://hdl.handle.net/10948/d1011916 , Small business -- Management -- Study and teaching -- South Africa , College teachers -- South Africa -- Attitudes , College students -- Rating of -- South Africa , College students -- South Africa -- Attitudes
  • Description: The perceptions of both students and teachers are vital to improve performance and to ensure a positive teaching and learning climate at a college. This study examines the perceptions of staff at three recently merged campuses and students regarding student performance. The research focuses specifically on the performance of students registered for the Small Business Management N3 and NSC (National Senior Certificate) curriculum. A combination of quantitative and qualitative research methods was employed to investigate the desired result. Staff teaching the subject (Small Business Management) were given semi-structured interviews, while students who are currently studying the subject were given questionnaires to complete. Data was collected and analysed. This study reveals amongst other findings that management in FET institutions needs to take cognisance of the perceptions of staff and students regarding the improvement of student performance. Opinions, attitudes, insights and recommendations expressed concerning student performance can help institutions improve their culture of teaching and learning.
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  • Date Issued: 2005

Photochemical and photophysical properties of pentoxy-and naphthaloxy appended magnesium and zinc phthalocyanines

- Maqanda, Wesiwe, Nyokong, Tebello, Maree, David M

  • Authors: Maqanda, Wesiwe , Nyokong, Tebello , Maree, David M
  • Date: 2005
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/289260 , vital:56613 , xlink:href="https://doi.org/10.1142/S1088424605000435"
  • Description: Photochemical and photophysical measurements were conducted on pentoxy and naphthaloxy appended zinc and magnesium phthalocyanines. We describe in this paper the synthesis as well as unexpected photodegradation behavior of naphthaloxy appended magnesium phthalocyanines. General trends are described for quantum yields of photodegradation, triplet lifetimes and triplet quantum yields as well as singlet oxygen quantum yields of these compounds.
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  • Date Issued: 2005

Photophysical and photochemical studies of non-transition metal phthalocyanine derivatives

- Ogunsipe, Abimbola Olukayode

  • Authors: Ogunsipe, Abimbola Olukayode
  • Date: 2005
  • Subjects: Photochemotherapy Phthalocyanines Spectrum analysis
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4445 , http://hdl.handle.net/10962/d1007721
  • Description: A detailed photophysicochemical study of some non-transition metal (AI, Zn, Si, Ge, and Sn) metallophthalocyanine (MPc) derivatives is presented. The effects of substituents, central metal ions and solvents on the photophysical and photochemical properties are investigated and rationalized accordingly. The presence of peripheral substituents on the macrocycle enhances the yield of the triplet state. Near infra-red absorptions of the solvents reveal that solvents which absorb around 1100 nm and around 1270 nm, quench the triplet state of the MPc derivative and singlet oxygen, respectively. Although water has a high singlet oxygen quenching effect, the singlet oxygen quantum yield (Φ∆) value for sulphonated zinc phthalocyanine in water is still reasonably high at 0.48, which may provide an explanation for the efficient photosensitization by this molecule in photodynamic studies. The lowering of Φ∆ following protonation of the MPc macrocycle is attributed to the lowering of triplet energy to the level where energy transfer to ground state oxygen is no longer favourable. MPc inclusion complexes with cyclodextrins showed larger Φ∆ values when compared to the complexes before inclusion. Job's plots show that 2:1 and 4:1 (CD:MPc) complexes may be formed. Fluorescence quenching by electron donors and acceptors were analysed by StemVolmer relationship and the results used in determining fluorescence lifetimes of the complexes. Qualitative and quantitative interpretations of the interaction of sulphonated MPcs with bovine serum albumin (BSA) are provided in this thesis. 1:1 adducts were formed with BSA, but the binding feasibilities varied markedly. Spectral, photophysical and photochemical properties of the complexes are altered in the presence of BSA.
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  • Date Issued: 2005

Photophysical and photochemical studies of sulphonated non-transition metal phthalocyanines in aqueous and non-aqueous media

- Ogunsipe, Abimbola, Nyokong, Tebello

  • Authors: Ogunsipe, Abimbola , Nyokong, Tebello
  • Date: 2005
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/289271 , vital:56614 , xlink:href="https://doi.org/10.1016/j.jphotochem.2005.03.001"
  • Description: The photophysical and photochemical parameters for mixed sulphonated metallophthalocyanine complexes (AlPcSmix, SiPcSmix, GePcSmix, SnPcSmix, and ZnPcSmix) are reported in phosphate buffer saline (PBS, pH 7.4), PBS containing the surfactant Triton X-100, and in dimethylsulphoxide (DMSO). The ground state spectra of SiPcSmix, GePcSmix and SnPcSmix show splitting of the Q-band in DMSO, but the fluorescence spectra have only one band, suggesting that only some components of the mixed complexes fluoresce. In general the quantum yields of fluorescence (ΦF) were smaller in DMSO compared to the aqueous solvents, while quantum yields of triplet state (ΦT) were larger in DMSO. Triplet lifetimes were much lower in aqueous solutions (compared to DMSO) due to the fact that water absorbs strongly around 1108 nm, which corresponds to the triplet energy of a metallophthalocyanine complex. The MPcSmix complexes quenched hydroquinone, and the Stern–Volmer constants follow the order: AlPcSmix > SiPcSmix > GePcSmix > ZnPcSmix > SnPcSmix which is the order of the extinction coefficients (of the low energy band for complexes with split Q-band) of these molecules. The rate constants for fluorescence, intersystem crossing, internal conversion, and photodegradation were determined from the hydroquinone quenching data.
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  • Date Issued: 2005

Photophysical properties of a water-soluble adjacently substituted bisnaphthalophthalocyanine

- Seotsanyana-Mokhosi, Itumeleng, Nyokong, Tebello

  • Authors: Seotsanyana-Mokhosi, Itumeleng , Nyokong, Tebello
  • Date: 2005
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/286091 , vital:56237 , xlink:href="https://doi.org/10.1142/S1088424605000599"
  • Description: Spectral properties of a water soluble metal free tetracarboxyphenoxy bisnaphthalo-phthalocyanine (3) were studied in water and organic solvents. It was found that in protic solvents, complex 3 was highly aggregated. The surfactant, Triton X100, and bovineserum albumin (BSA) do not effect disaggregation while cetyl trimethylammonium chloride (CTAC) caused the molecule to disaggregate. The fluorescence quantum yields were higher in the presence of CTAC. Studying the interaction of BSA with complex 3 using fluorometry revealed that BSA is highly quenched by the latter. A 1:1 stoichiometric binding ratio between BSA and the Pc was found. Triplet quantum yields in water containing CTAC were higher than in organic solvents.
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  • Date Issued: 2005

Phylogenetic congruence of mealybugs and their primary endosymbionts

- Downie, Douglas A, Gullan, P J

  • Authors: Downie, Douglas A , Gullan, P J
  • Date: 2005
  • Language: English
  • Type: Article
  • Identifier: vital:6905 , http://hdl.handle.net/10962/d1011858 , http://dx.doi.org/10.1111/j.1420-9101.2004.00834.x
  • Description: Tight interactions between unrelated organisms such as is seen in plant–insect, host–parasite, or host–symbiont associations may lead to speciation of the smaller partners when their hosts speciate. Totally congruent phylogenies of interacting taxa have not been observed often but a number of studies have provided evidence that various hemipteran insect taxa and their primary bacterial endosymbionts share phylogenetic histories. Like other hemipterans, mealybugs (Pseudococcidae) harbour multiple intracellular bacterial symbionts, which are thought to be strictly vertically inherited, implying codivergence of hosts and symbionts. Here, robust estimates of phylogeny were generated from four fragments of three nuclear genes for mealybugs of the subfamily Pseudococcinae, and a substantial fragment of the 16S–23S rDNA of their P-endosymbionts. Phylogenetic congruence was highly significant, with 75% of nodes on the two trees identical, and significant correlation of branch lengths indicated coincident timing of cladogenesis. It is suggested that the low level of observed incongruence was influenced by uncertainty in phylogenetic estimation, but evolutionary outcomes other than congruence, including host shifts, could not be rejected.
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  • Date Issued: 2005

Phylogeography and comparative ecophysiology of Chrysanthemoides Turn. Ex Medik. (Tribe Calenduleae)

- Howis, Seranne

  • Authors: Howis, Seranne
  • Date: 2005
  • Subjects: Chrysanthemoides , Phylogeny , Ecophysiology , DNA , Plant genetics
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4256 , http://hdl.handle.net/10962/d1008189
  • Description: Chrysanthem Oides is a common Southern African shrub that grows in a variety of habitats. From coastal shrubland and fynbos to mountainous areas as far north as Kenya. The genus has two species and 8 subspecies. The diagnoses and delimitation of which have been based almost exclusively on morphological characteristics. This project aims to investigate, with the use of phylogenetic species concepts. The validity of these subspecies. Unlike biological species concepts that rely on reproductive isolation as a defining character of a species. Phylogenetic species concepts (PSC) are concerned with delimiting evolutionary significant units (ESUs). ESUs are evolutionarily isolated lineages, and under the PSC a species is an aggregation of organisms consistently diagnosable by a fixed character or combination of characters. This project therefore searched for genetic and physiological characters by which to delimit ESUs within the Cill), samhemoides genus. DNA sequencing was used to investigate the genetic characters, while gas exchange studies were used to investigate the ecophysiological characters. DNA sequence analysis indicated that the ESUs can be diagnosed by genetic means and that one species may be of hybrid origin. Field studies of three disparate genetically identifiable ESUs from three disparate climates found that there are noticeable differences in ecophysiological responses of these ESUs in the field. Plants from each ESU were transferred to a greenhouse and grown under identical conditions for several months and compared to determine if these traits are inherent, or elastic in relation to environmental conditions. Under simulated high rainfall conditions. There does not appear to be a significant difference in the photosynthetic traits.
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  • Date Issued: 2005

Playing musement games: Retroduction in social research, with particular reference to indigenous knowledge in environmental and health education

- Price, Leigh

  • Authors: Price, Leigh
  • Date: 2005
  • Subjects: To be catalogued
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/373763 , vital:66722 , xlink:href="https://www.ajol.info/index.php/sajee/article/view/122701"
  • Description: My aim here is to introduce the concept of musement (retroduction or abduction) as an appropriate alternative to deduction and induction, both in indigenous knowledge (IK) specifically and in social science generally. As an example, I will use musement to tentatively address some of the ethical problems of using indigenous knowledge (IK) in environmental education and health education. This paper will therefore be of use both to researchers/educators wanting a discussion of retroduction, and researchers/educators wanting a discussion of indigenous knowledge epistemology and its relationship with ethics. I am arguing, from a perspective that allows a stratified reality (things can be real even if not measurable or actually present), that, we admit retroduction into our list of allowable research logics. In terms of IK, the result of accepting retroduction as a valid logic is that we allow IK to be dynamic and non-reified. It also allows a previously ignored aspect of IK, its spiritual/non-empirical beliefs, to be validated through ethical outcomes experienced in our lives, rather than through the previous criteria of empirical validity. In other words, we ask for IK: does believing in (whatever) adequately explain experience and/or provide optimistic, long term, ethical, appropriate ways of living? Thus, retroduction has the potential to allow IK to contribute to a normative ethics.
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  • Date Issued: 2005

Population dynamics of selected ichthyofaunal components in the temperate, temporarily open/closed Kasouga Estuary, South Africa

- Tweddle, Gavin Paul

  • Authors: Tweddle, Gavin Paul
  • Date: 2005
  • Subjects: Estuaries -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5742 , http://hdl.handle.net/10962/d1005428 , Estuaries -- South Africa -- Eastern Cape , Estuarine fishes -- South Africa -- Eastern Cape , Estuarine ecology -- South Africa -- Eastern Cape
  • Description: The spatial and temporal pattern of ichthyofaunal community composition in relation to selected physico-chemical (temperature and salinity) and biological variables (chlorophyll-a and zooplankton) was investigated at ten stations in the temperate temporarily open/closed Kasouga estuary. In addition, the food web structure in the estuary was investigated using stable carbon isotope analysis. Results of the 5 metre seine net survey indicated that ichthyofaunal composition and biomass in the Kasouga estuary was largely determined by seasonality and mouth condition. Maximum abundance and biomass of ichthyofauna was recorded during summer or during those periods when overtopping occurred. Overtopping coincided with the recruitment of marine estuarine dependant species, which dominated the catches both numerically and in biomass. The recruitment of these species resulted in an increase in diversity of the ichthyofaunal community. There were no significant spatial patterns in the distribution of smaller ichthyofauna (<50mm SL) identified in Bray-Curtis similarity matrices using cluster analysis (Primer 5 v5.2.4). Spearman’s correlation analysis revealed that there were no significant correlations between abundance and biomass of ichthyofauna and selected physico-chemical and biological variables other than salinity (P>0.05 in all other cases). There were two distinct spatial patterns in the distribution of the larger ichthyofauna (>50mm SL). These corresponded to a grouping associated with the mouth region and a grouping associated with the remaining regions of the estuary. Stable isotope analysis indicated that the primary source of carbon utilised by the ichthyofauna of the Kasouga estuary was derived from the channel, most likely microphytobenthic algae. The contributions of the riparian and salt marsh vegetation to the total carbon flow appear to be minimal.
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  • Date Issued: 2005

Population structure, physiology and feeding ecology of the mysid Mesopodopsis wooldridgei (Whittmann) in a large permanently open estuary

- Mesher, Colette Suzanne

  • Authors: Mesher, Colette Suzanne
  • Date: 2005
  • Subjects: Mysidacea -- Physiology , Mysidacea -- Ecology , Mysidacea -- Feeding and feeds , Zooplankton -- South Africa -- Great Fish Estuary
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5746 , http://hdl.handle.net/10962/d1005432 , Mysidacea -- Physiology , Mysidacea -- Ecology , Mysidacea -- Feeding and feeds , Zooplankton -- South Africa -- Great Fish Estuary
  • Description: This project had three main aims. The first aim was to investigate the metabolic physiology of the mysid Mesopodopsis wooldridgei. Secondly, the study examined the contribution of the mysid to the zooplankton community. Finally the study attempted to clarify the primary sources of carbon utilised by the mysid using stable carbon isotope analysis. The study was conducted in the freshwater dominated permanently open Great Fish Estuary (33°30’S; 27°08’E) located along the south-eastern coastline of southern Africa. Mass specific oxygen consumption rates of Mesopodopsis wooldridgei ranged between 0.11 and 8.38 ml O2 mg ww-1 h-1 and increased with an increase in water temperature. There were no significant differences in the respiration rates between the male and female mysids (P > 0.05). At a constant temperature (20°C), the oxygen consumption rate of M. wooldridgei decreased with an increase in salinity. Salinity tolerance of the mysid was strongly modified by temperature. At 5‰ and 30°C, mysids exhibited mass mortality. The Q10 value for M. wooldridgei at 15, 25 and 35‰ was estimated at 2.34, 1.44 and 2.14, respectively. Results of the study suggest that M. wooldridgei is well adapted to surviving in environments characterised by variations in temperature and salinity. Within the Great Fish Estuary, total chl. a concentration ranged between 2.68 μg L-1 and 31.12 μg L-1 and was always dominated by large phytoplankton cells (>5 μm). Average zooplankton abundance ranged between 62 and 28 917 ind. m-3 and biomass between 10 and 203 mg Dwt m-3. The zooplankton community was numerically dominated by the calanoid copepod Pseudodiaptomus hessei, which comprised up to 100% (range between 12 and 100%) of the total zooplankton counted. Total zooplankton biomass during the day was dominated by copepods and by mysids during the nighttime. Among the mysids, M. wooldridgei was the most numerically abundant mysid and comprised <10% of the total zooplankton abundance. Numerical analysis found no seasonal pattern in the total zooplankton abundance (including mysids). The lack of any seasonality could be attributed to the continuous freshwater inflow into the estuary due to the inter-basin transfer of water from the Gariep Dam to the Fish River system. A distinct spatial pattern in the zooplankton community structure was evident with the upper stations almost entirely dominated by the copepod P. hessei, while at stations occupied in the lower reaches of the estuary, the zooplankton community comprised a mixture of freshwater, estuarine and marine breeding zooplankton species. The mysids also demonstrated a distinct spatial pattern in their distribution. Mysids were generally absent from the upper reaches, while in the middle reaches Rhopalophthalmus terranatalis and M. wooldridgei were numerically dominant. Gastrosaccus brevifissura dominated in the lower regions of the estuary. Stable isotope analysis (δ13C) indicated that the dominant source of carbon utilised by the numerically dominant copepods and juvenile M. wooldridgei within the estuary was derived from the extensive phytoplankton stocks within the system. In contrast, sub-adult and adult mysids (R. terranatalis, M. wooldridgei and G. brevifissura) appeared to consume a combination of phytoplankton and copepods. The contribution of the various sources of carbon to the total carbon intake of the mysid remains unknown.
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  • Date Issued: 2005

Post-traumatic stress disorder as a public health concern in South Africa

- Edwards, David J A

  • Authors: Edwards, David J A
  • Date: 2005
  • Language: English
  • Type: Article
  • Identifier: vital:6229 , http://hdl.handle.net/10962/d1007779
  • Description: This article briefly surveys the extent to which traumatic events are a feature of life all over Africa and provides a comprehensive review of research that documents the pervasiveness of traumatic events in South Africa and the prevalence of PTSD symptoms. The material reviewed includes statistics on crime, violence and accidents, research from clinical settings, and surveys. Several provide evidence for the causal link between traumatic events and the development of PTSD. These studies show that PTSD has been and continues to be a significant problem for public health in South Africa, affecting individuals in all sectors of society and as much a concern with respect to children as to adults.
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  • Date Issued: 2005

Primary caregivers' experience of raising children with autism: a phenomenological perspective

- Swanepoel, Yolandi

  • Authors: Swanepoel, Yolandi
  • Date: 2005
  • Subjects: Autism in children Autistic children Autism in children -- Diagnosis Parents of autistic children
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:3067 , http://hdl.handle.net/10962/d1002576
  • Description: Autism occupies an extreme position among childhood pathologies due to its severity, duration and impact on the family. In this qualitative study, four primary caregivers of autistic children were interviewed regarding their experiences of the diagnostic process, their post-diagnostic adjustment, and how helping professionals can improve their service rendering to these families. This study utilised a phenomenological approach to look at primary caregivers as the best-informed authority to explore and describe their lived realities and experiences of raising their autistic children in South Africa. The rationale for a phenomenological approach in this study is that such an interpretative inquiry enables material to be collected and analysed within the specific context of the subjective realities of primary caregivers of autistic children in South Africa. The researcher utilised semi-structured, in-depth, face-to-face interviews as method of data collection. Each participant was interviewed over the course of three separate interviews. The themes and categories that resulted from a content analysis of the material were grouped into two broad fields of experience, namely: (1) experiences surrounding the diagnostic process; and (2) the pervasive influence of autism on different areas of family life. In terms of experiences surrounding children’s diagnosis, four themes were identified: (1) Being a new parent and making sense out of chaos; (2) Responsibility and blame; (3) Confusion and disillusionment during early experiences with helping professionals; and (4) Feelings about the diagnosis. The pervasive influence of autism on different areas of family life includes: (5) Strained family relationships; (6) Challenges of behaviour management and disciplining the autistic child; (7) Challenges of finding suitable resources for education and day-care; and (8) Maintaining the family unit and doing things as a family.
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  • Date Issued: 2005

Primary school children's experiences in their loss of a parent

- Hildebrand, Paula

  • Authors: Hildebrand, Paula
  • Date: 2005
  • Subjects: Children and death -- South Africa , Parents -- South Africa -- Death -- Psychological aspects , Grief in children
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:9984 , http://hdl.handle.net/10948/446 , Children and death -- South Africa , Parents -- South Africa -- Death -- Psychological aspects , Grief in children
  • Description: This study aims to discover the meaning that primary school children place on the loss of a parent and the impact it has on the children’s lives. As it is an emotive topic, and because of the difficulties of interviewing children, qualitative techniques of research data collection are considered the most appropriate. The study will explore, discover and describe children’s personal experiences of loss in a phenomenological and contextual manner. The sample in the study will be selected according to non-probability and purposive sampling techniques. Because children are being interviewed, the researcher will ethically approach gatekeepers for permission, and gain their informed consent. Data will be collected using semi-structured interviews, in which the researcher will interact with the interviewees in a natural setting. Data analysis will be done according to Tesch’s eight steps for analysing qualitative research data (Creswell, 1994:155). Once this process has been completed, the data will be verified against the four criteria that Guba (in Krefting, 1991:214-222) developed for testing the trustworthiness of qualitative research findings. The results of the study, as well as conclusions and recommendations drawn from the data, will be disseminated by means of a written report.
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  • Date Issued: 2005

Procedural meanings of well in a corpus of Xhosa English

- De Klerk, Vivian A

  • Authors: De Klerk, Vivian A
  • Date: 2005
  • Language: English
  • Type: Article
  • Identifier: vital:6128 , http://hdl.handle.net/10962/d1011579
  • Description: This article explores the use of the pragmatic marker well in a large corpus of the discourse of non-mother tongue speakers of Xhosa English, which is a sub-variety of Black South African English. A brief overview of discourse markers in general and of well in particular is provided, and the problems they pose to linguists in terms of difficulties in defining their syntactic, semantic and pragmatic properties are examined. After a brief description of the nature of the corpus of Xhosa English on which the study is based, and of the methodological approach which was followed, the rest of the article focuses on a fairly detailed exposition of the overall trends in contextualised uses and procedural meanings of well in the corpus, along with examples. Some (limited) parallels are drawn between the use of well in XE and other English corpora, in order to highlight the problems experienced by L2 learners in acquiring discourse markers.
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  • Date Issued: 2005

Producing and sharing ICT-based knowledge through English and African languages at a South African university

- Terzoli, Alfredo, Dalvit, Lorenzo, Murray, Sarah, Mini, Buyiswa, Zhao, Xiaogeng

  • Authors: Terzoli, Alfredo , Dalvit, Lorenzo , Murray, Sarah , Mini, Buyiswa , Zhao, Xiaogeng
  • Date: 2005
  • Language: English
  • Type: text , article
  • Identifier: http://hdl.handle.net/10962/428531 , vital:72518 , https://hdl.handle.net/10520/EJC37193
  • Description: This article describes an intervention aimed at providing increased ac-cess to the study of information and communication technology (ICT) and computer literacy in Higher Education in South Africa. Our focus group is speakers of an African language from a previously disadvan-taged background in the extended studies programme at Rhodes Uni-versity. Preliminary investigation suggests that such students have dif-ficulties becoming computer literate partly because of their lack of Eng-lish proficiency. This might prevent them from furthering their studies of Computer Science (CS) up to the postgraduate level. Shifting away from the dominant approach to academic support in extended studies programmes in South Africa, in our research we focus primarily on the lexical rather than the discourse level. With the help of a web-based application, students collaboratively produce and share additional mate-rial in both English and the African languages. This allows them to inte-grate new concepts and knowledge about computers into their existing knowledge structures. With our intervention, we hope to improve the students' participation in the production and sharing of knowledge in the field of ICT.
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  • Date Issued: 2005

Progress in ringing : an African experience

- Lewis, Colin A

  • Authors: Lewis, Colin A
  • Date: 2005
  • Language: English
  • Type: Article
  • Identifier: vital:6172 , http://hdl.handle.net/10962/d1012363
  • Description: Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
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  • Date Issued: 2005

Psychotherapy for post-traumatic stress disorder in a young rape survivor: a case study

- Labe, Dana

  • 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

Puerulus and early juvenile recruitment of the rock lobster jasus lalandii in relation to the environment at Lüderitz Bay, Namibia

- Keulder, Felicia Juanita

  • Authors: Keulder, Felicia Juanita
  • Date: 2005
  • Subjects: Jasus lalandii , Lobster fisheries -- Namibia , Lobster culture -- Namibia
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5315 , http://hdl.handle.net/10962/d1005160 , Jasus lalandii , Lobster fisheries -- Namibia , Lobster culture -- Namibia
  • Description: A global decline in the lobster fishery has necessitated the growout of wild-caught postlarvae (pueruli) on farms to meet the worlds lobster demand. A limited knowledge on puerulus settlement in the West Coast rock lobster (Jasus lalandii) constitutes a major barrier for J. lalandii culture development in Southern Africa. As an extension of an existing long-term puerulus monitoring program of the Ministry of Fisheries and Marine Resources of Namibia, the present study monitored puerulus recruitment (supply), puerulus condition and juvenile growth of J. lalandii and their relationship with environmental variables on an oyster farm at Lüderitz Bay, Namibia. Implications for lobster aquaculture and fisheries management are discussed. Oyster bags, crates and collectors were sampled daily, weekly and bimonthly, for pueruli and juveniles, respectively, between August 2001 and July 2003 to establish spatialtemporal patterns in their distribution. Animals were transported to the laboratory for morphometric analyses where they were staged as puerulus (Pt = transparent; Pp = pigmented) and juvenile lobsters. The carapace lengths (0.1mm CL) and wet weights (0.01gram) of animals were recorded. Carapace length frequencies were subjected to Modal Progression analysis to identify early juvenile cohorts and calculate their growths. The weight-length ratios calculated and percentage fat content were used as indices of nutritional condition. Seasonal peaks in puerulus and juvenile abundance were estimated using Periodic Regression analysis. The relationships of puerulus and juvenile abundance with respect to sea surface temperature (SST), wind speed-direction, moon phase, swell and tidal range were established using time lag analysis (ADL). Transparent pueruli were randomly distributed on oyster bags and crates, and also between collector sites, suggesting that they have no particular settlement preference for certain areas on these structures (p>0.05; n=150). Pigmented puerulus (p<0.05; n=566) and juveniles (p<0.05; n=3528) preferred structurally complex structures that provided better shelter such as crates, which were more sheltered from sea swells, compared to oyster bags. Among oyster rafts, pigmented puerulus and juveniles preferred occupying the sheltered and centred raft areas, which provided better protection from wave action, compared to exposed raft areas, which were exposed to the incoming swell. Puerulus and juvenile lobster appeared to recolonise adjacent bags and crates, and possibly migrate to the substrate and off the farm due to the disturbance of the habitat during harvesting. The booth crevice collector was more efficient in collecting puerulus possibly due to the high structurally complex habitat and the better shelter they provided compared to the hogshair collector. The occupation of structurally complex habitats by early benthic stages may be related to morphological changes associated with metamorphosis. Puerulus settlement peaked during early spring (August-September) and was related to low sea surface temperatures (12.3°C), strong south winds, and moderate swells in the week preceding settlement. These conditions are synonymous with the “spring upwelling” season of the Lüderitz upwelling cell in the central Benguela current region. Puerulus nutritional condition peaked during this period possibly due to high levels of planktonic food (due to high nutrients from upwelling) that was available to the late stage phyllosoma larvae further offshore. A “good” puerulus settlement year during 2000 was associated with lower than average SST (11.6°C) and strong south winds and was followed by “poor” puerulus settlement years during 2001 and 2002 when higher than average SST were experienced with below average wind speeds experienced during 2001 only. Puerulus of J. lalandii recruited in high numbers into Lüderitz Bay during the new moon, full moon and last quarter moon phases by making use of the increased tides during these phases of the lunar cycle. Peak juvenile abundance during early summer (November-December) lagged by 8 weeks was significantly correlated with peak puerulus abundance. Puerulus size was similar (8.5–9.7mm CL) over the study period. Juvenile cohorts, 9.9-20.6mm CL in size recruited in 2 distinct waves in August 2001-June 2002 and July 2002-February 2003. The 2001/2002 recruits had higher monthly growth increments and better nutritional condition compared to 2002/2003 recruits. Peak frequencies of 2nd moult juveniles (9.9- 10.8mm CL) occurred in September of both recruitment events with nutritional condition being poorest during the 2002/2003 event. The nutritional condition of the settling puerulus did not appear to be related to the subsequent growth of juvenile lobster. These preliminary results suggest that pueruli recruit once a year mainly during late winter/ early spring under conditions typical of coastal upwelling in the Benguela current near Lüderitz. It appears that puerulus settlement is driven by favourable shoreward currents, which help in transporting puerulus to their settlement grounds. Puerulus supply is highly variable between years, which appears to be consistent with a highly variable Benguela environment. The oyster farm supported a substantial standing stock averaging 123 800 lobster per day (range: 22 600-325 300 lobster per day) of which 26 600 were puerulus and 97 200 were juveniles, that may have been harvested once off on any given day during the sample period. Monthly harvesting of the total lobster standing stock during the one and a half year sampling period was just over 2 million lobsters (505 700 pueruli and 1.85 million juveniles) and would potentially have been sufficient seed for a 200 ton lobster production in puerulus lobster growout facilities. In the light of high inter-annual variation in puerulus settlement observed at Lüderitz, the seed supply at the Lüderitz oyster farm is clearly limited and therefore it is prudent that other sites of high puerulus settlement is established before large commercial scale lobster growout can commence. The migration of lobster off the farm suggested that these lobsters potentially recruit to the fishery and therefore harvesting the entire standing stock on the farm may have adverse negative effects on the wild fishery. A policy decision will be required as to whether more efficient harvesting of lobster from the farm should be allowed. If puerulus removal in J. lalandii for aquaculture is allowed in the near future, it should be conducted on an experimental scale or small commercial scale until the potential effects on recruitment into the fishery are clearer.
  • Full Text:
  • Date Issued: 2005

Rainfall variability in Southern Africa, its influences on streamflow variations and its relationships with climatic variations

- Valimba, Patrick

  • Authors: Valimba, Patrick
  • Date: 2005
  • Subjects: Rain and rainfall -- Africa, Southern Climatic changes -- Africa, Southern Streamflow -- Africa, Southern
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:6030 , http://hdl.handle.net/10962/d1006159
  • Description: Hydrological variability involving rainfall and streamflows in southern Africa have been often studied separately or have used cumulative rainfall and streamflow indices. The main objective of this study was to investigate spatio-temporal variations of rainfall, their influences on streamflows and their relationships with climatic variations with emphasis on indices that characterise the hydrological extremes, floods and droughts. It was found that 60-70% of the time when it rains, daily rainfalls are below their long-term averages and daily amounts below 10 mm are the most frequent in southern Africa. Spatially, climatologies of rainfall sub-divided the southern African subcontinent into the dry western/southwestern part and the “humid” eastern and northern part. The daily amounts below 20 mm contribute significantly to annual rainfall amounts in the dry part while all types of daily rainfall exceeding 1 mm have comparable contributions in the humid part. The climatologies indicated the highest likelihood of experiencing intense daily events during the core of the wet seasons with the highest frequencies in central Mozambique and the southern highlands of Tanzania. Interannual variations of rainfall indicated that significant changes had occurred between the late-1940s and early-1980s, particularly in the 1970s. The changes in rainfall were more evident in the number of daily rainfall events than in rainfall amounts, led generally to increasing early summer and decreased late summer rainfall. It was also found that intra-seasonal dry day sequences were an important parameter in the definition of a rainy season’s onset and end in southern Africa apart from rainfall amounts. Interannual variations of the rainy season characteristics (onset, end, duration) followed the variations of rainfall amounts and number of events. The duration of the rainy season was affected by the onset (Tanzania), onset or end (tropical southern Africa - southwestern highlands of Tanzania, Zambia, northern Zimbabwe and central Mozambique) and end (the remaing part of southern Africa). Flow duration curves (FDCs) identified three types of rivers (ephemeral, seasonal and perennial) in southern Africa with ephemeral rivers found mainly in the dry western part of the region. Seasonal streamflow patterns followed those of rainfall while interannual streamflow variations indicated significant changes of mean flows with little evidences of high and low flow regime changes except in Namibia and some parts of northern Zimbabwe. It was, however, not possible to provide strong links between the identified changes in streamflows and those in rainfall. Regarding the influences of climate variability on hydrological variability in southern Africa, rainfall variations in southern Africa were found to be influenced strongly by ENSO and SST in the tropical Indian ocean and moderately by SST in the south Madagascar basin. The influence of ENSO was consistent for all types of daily rainfall and peaks for the light and moderate (< 20 mm) events in the southern part and for the intense events in the northern part. SST in the tropical Indian ocean influence the light and moderate events while SST close to the region influence the heavy events. However, the relationships experienced significant changes in the mid-1950s and in the 1970s. The former changes led to improved associations while the latter deteriorated or reversed the relationships. The influences of climatic variables on streamflows and rainy season characteristics were inferred from the rainfall-streamflow and rainfall-climatic variables relationships.
  • Full Text:
  • Date Issued: 2005
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