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Effects of temperature on the development, behaviour and geography of blowflies in a forensic context

  • Authors: Richards, Cameron Spencer
  • Date: 2008
  • Subjects: Blowflies Blowflies -- South Africa Diptera -- South Africa Insects -- Development Insects -- Behavior Forensic entomology
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5683 , http://hdl.handle.net/10962/d1005369
  • Description: The development of immature insects is commonly employed in forensic investigations to estimate time of death, or postmortem interval (PMI), of a corpse on which they are feeding. The bulk of this thesis focuses on factors influencing the accuracy of developmental data, and exploring how and why developmental data differ between studies involving the same species, and between different species. Because carrion feeding insects are ectotherms, temperature may be expected to significantly influence their behaviour, development and distribution, and the remainder of the thesis therefore focuses on the thermal biology and geographical distribution of seven forensically important blowflies. The species include Chrysomya albiceps, C. putoria, C. chloropyga, C. megacephala, C. marginalis, C. inclinata and Calliphora croceipalpis. A robust experimental design for estimating developmental models is outlined and tested. It is recommended that forensic entomologists should involve at least six constant temperatures, starting at about 7°C above the relevant developmental zero (D0) and going to about 10°C above the upper critical temperature, and a temporal sampling interval with a relative precision of about 10%. Using this design, focused experiments consistently provided the most reliable developmental data, while data pooled from different studies yielded inconsistent results. Similarly, developmental data from closely related species differed significantly, and surprisingly so did developmental data from different populations of the same species. Possible explanations for the latter lay in the different methods of data collection but only temporal sampling resolution had a direct influence on the accuracy of developmental data. Consequently, disparities in such data were primarily ascribed to genetic differences and phenotypic plasticity. Comparisons between numerous thermal thresholds of larvae, pupae and adults support this conclusion and suggest a phylogenetic component to the thermal biology of blowflies. Further comparisons were made between these temperature thresholds and the distributions of blowfly species present on two rhinoceros carcasses. These comparisons suggest that blowfly larvae with high upper lethal temperature thresholds dominate in interspecific competition in favorable thermal environments by raising maggot mass temperature above the thresholds of other carrion-feeding blowflies, through maggot-generated heat. Bioclimatic modeling using maximum entropy analysis provided a successful means of predicting whether a species is likely to occur in an area, and whether it would therefore be expected in a local carcass community. It also showed that temperature was less important than moisture in shaping the geographical distribution of African carrion blowflies. Based on these results, several recommendations are made for the practice of forensic entomology.
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  • Date Issued: 2008

Relating indigenous knowledge practices and science concepts : an exploratory case study in a secondary school teacher-training programme

  • Authors: Mandikonza, Caleb
  • Date: 2007
  • Subjects: Ethnoscience -- Study and teaching (Secondary) -- Zimbabwe Science -- Study and teaching (Secondary) -- Zimbabwe Teachers -- Training of -- Zimbabwe
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1918 , http://hdl.handle.net/10962/d1007321
  • Description: This study reports research on how student teachers in Science at Mutare Teachers' College in Zimbabwe worked with indigenous knowledge practices in relation to science concepts in the secondary school syllabus. The study was conducted among first-year science students and involved them in developing science learning activities for a peer-teaching process that was part of their course. The research was undertaken during a review ofthe college syllabus and as a study to inform the Secondary Teacher Training Environmental Education Programme (ST²EEP). The research design involved the researcher in participant observations and interviews with rural people to document indigenous knowledge practices and to develop materials for the students to work with in the lessons design part of the study. The student teachers used the documented practices to generate learning activities and lesson plans to teach the science concepts they had identified. A peer review session and focus group interviews followed the lesson presentations. Findings from the research point to the rural community being a repository of diverse indigenous knowledge practices. Student teachers showed that they had prior knowledge of both indigenous knowledge practices and science concepts when they come to class. Student teachers were able to relate indigenous knowledge practices and science concepts in ways that have the potential to enhance the learning of science in rural school contexts that lack laboratories and science equipment. The scope of the study does not allow for anything beyond tentative conclusions that point to the need for further work to be undertaken with student teachers and for the research to be extended to teaching and learning interactions in schools. Recommendations are also made for further resource-based work to be undertaken within the forthcoming St²eep implementation phase in 2007.
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  • Date Issued: 2007

The significance of participation in capacity development and project sustainability: a case study of the Zimbabwe Secondary Teacher Training Environmental Education Project (St²eep)

  • Authors: Van Ongevalle, Jan
  • Date: 2007
  • Subjects: High school teachers -- Training of -- Zimbabwe Environmental education -- Study and teaching (secondary) -- Zimbabwe Environmental education -- Curricula -- Case studies -- Zimbabwe Environmental education -- Curricula -- Zimbabwe
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1766 , http://hdl.handle.net/10962/d1003651
  • Description: This study uses a systems thinking perspective to explore the role and meaning of participation, capacity development and project sustainability in the Zimbabwe Secondary Teacher Training Environmental Education Project (St²eep). Since there was no consistent critical reflection upon the different assumptions that underpin these important aspects of St²eep in the original project design, this study aims to articulate a theoretical framework for guiding the project. St2eep is a donorfunded project, located in the Ministry of Higher and Tertiary Education in Zimbabwe that seeks to integrate environmental education across the curriculum of secondary teacher education. The study first develops a theoretical framework drawing on systems thinking. In particular it uses the holistic and constructivist perspectives embedded in systems thinking to describe a number of analytic frameworks that are used as a guide to investigate participation, capacity development and project sustainability in the St²eep case study. The research methodology comprises a qualitative case study approach, which contains elements of an instrumental, evaluative and critical case study. Data-collection methods include document analysis, focus group discussions, focus group interviews, semi-structured face-to-face interviews and participant observation. Data analysis follows the constant comparative method of coding and categorising data as outlined by Strauss and Corbin (1998). The outcomes of this research show that participation processes in St²eep evolve around the interactions between a political dimension and a learning dimension. The political dimension relates to giving the project stakeholders a critical voice, allowing them to shape the project and involving them in the decision-making process. This approach has fostered an ongoing learning process in a small team of committed stakeholders based on the principles of collaborative learning, team learning and action research. Participation was shown to enhance capacity-development processes at individual and institutional level by the provision of support through learning teams, and by the renegotiation of responsibilities and power relations between lecturers involved in St²eep, donor representatives and college administrations. The strong operational role of the donor organisation was seen as a serious threat towards individual and institutional capacity development since it creates a functional but artificial and independent project system within the college system and takes over any local institutional support structure that it might seek to develop. Fostering continuous learning and capacity development, St²eep’s participatory approach was shown to contribute to a better understanding of the interconnectedness of factors that influence future sustainability of the project and the implementation of environmental education. This has assisted in the development of different scenarios on the sustainability of the project. The research shows that the project-ustainability planning process draws directly from St²eep’s ongoing learning process, with individual and institutional capacity development featuring strongly in the different scenarios, and with the external context such as the economic situation and the low priority of environmental education being recognised as important factors that need to be considered. Drawing on the findings from the case study, this study makes a tentative recommendation that donor organisations should focus more on capacity-development initiatives and avoid taking on a strong operational role in project activities. The research also recommends that there is need for a deliberate focus on both the political and learning dimensions of the participation process in order to foster local ownership. Making the learning aspect much more central in St²eep is presented as a possible strategy for motivating a larger number of college lecturers to become involved in the project and the implementation of environmental education. The study also urges St²eep to combine the different scenarios that have emerged during the project sustainability planning process and to focus on the benefits that stakeholders want to see sustained.
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  • Date Issued: 2007

The use of Van Hiele's theory to explore problems encountered in circle geometry: a grade 11 case study

  • Authors: Siyepu, Sibawu Witness
  • Date: 2005
  • Subjects: Geometry -- Study and teaching (Secondary) -- South Africa Mathematics -- Study and teaching (Secondary) -- South Africa Mathematics teachers -- Training of -- South Africa Mathematical ability -- Testing
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1871 , http://hdl.handle.net/10962/d1004777
  • Description: The research presented in this thesis is a case study located in the interpretive paradigm of qualitative research. The focus is on the use of van Hiele's theory to explore problems encountered in circle geometry by grade 11 learners and making some policy recommendations concerning the curriculum structure and teaching of the geometry at all grades. The interpretation is based to the learners' background in geometry i.e. their prior knowledge and experience of learning geometry. The study was carried out over a period of three years. The data collection process took a period of two months (April and May 2003) with a group of 21 grade 11 mathematics learners in a rural senior secondary school in the Eastern Cape. The researcher used document analysis, worksheets, participants' observation, van Hiele tests, a questionnaire and semi-structured interviews to collect data. The study showed that the structure of the South African geometry syllabus consists of a some what disorganized mixture of concepts. It is not sequential and hierarchical and it sequences concepts in a seemingly unrelated manner. The study revealed that the South African high school geometry curriculum is presented at a higher van Hiele level than what the learners can attain. The findings of the study showed that many of the grade 11 learners were under-prepared for the study of more sophisticated geometry concepts and proofs. Three categories of reasons could be ascribed to this: Firstly, there was insufficient preparation of learners during the primary and senior phases. Secondly the study indicated that there is overload of geometry at the high school level in the South African mathematics curriculum. Thirdly, the over-reliance on the traditional approach to teaching geometry, poor presentation of mathematical technical concepts and language problems, were identified as possible additional reasons for the poor learner understanding of geometry in general and circle geometry in particular. The study recommends that the structure of the South African geometry curriculum should be revisited and redesigned. Teachers should be empowered and developed to be more effective in teaching geometry through further studies in mathematics and in-service workshops. They should also be engaged in the process of implementing the van Hiele's theory in the teaching of geometry in their classrooms.
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  • Date Issued: 2005

Teacher responses to the Namibian education reform : a case study of two Caprivi schools

  • Authors: Kamwi, Kamwi Kenneth
  • Date: 2002
  • Subjects: Education -- Namibia Education and state -- Namibia Educational change -- Namibia
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1791 , http://hdl.handle.net/10962/d1003676
  • Description: Effective implementation of education reforms consists of alterations in curriculum materials, instructional practices and behaviour, beliefs and understandings on the part of the teachers involved in the reform (Fullan and Hargreaves, 1993: 5). A process of implementation is therefore, a learning process, learning how to do something new (ibid.). This study was done to establish how Biology teachers in Caprivi have responded to the reform process ten years down the line. I used a qualitative case study of two secondary schools. Four Biology teachers, two school principals and two groups of learners participated in the study. Data was collected by means of interviews, lesson observations, a workshop, and school inventories. The data was analysed within an interpretive framework. The results of the study show a move into 'activity-based teaching'. It shows a shift from the traditional transmission teaching approach. In general teachers seem to equate 'activity-based teaching' with the learner-centred approach.
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  • Date Issued: 2002

The notion of commitment in selected works of Maishe Maponya

  • Authors: Moorosi, Mabitle
  • Date: 1998
  • Subjects: Maponya, Maishe , Commitment (Psychology) in literature
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2142 , http://hdl.handle.net/10962/d1002374 , Maponya, Maishe , Commitment (Psychology) in literature
  • Description: This study is a critical analysis of selected works of the playwright Maishe Maponya namely, The Hungry Earth, Jika and Gangsters. The main thrust of the analysis of the thesis is centred on questions around what 'Commitment' might mean in literature and drama. This concept has appeared in many names and guises. In theatre, it has assumed names like Theatre of Commitment, Theatre of the Dispossessed, Theatre ofthe Oppressed, Theatre of Resistance, as well as Theatre of Radicalization (Bentley 1968; Boal 1974; Mda 1985; Maponya 1992). These names came into existence as a result of a concerted effort to refrain from the use of the traditional conventional theatre, which does not appear to address itself to societal problems - the preoccupation of Theatre of Commitment. Chapter One is principally concerned with the concept of Commitment and its implications in art and literature, more specifically in theatre. Further, the following interacting elements in South African theatre are highlighted: censorship, banning, detention and other restrictions, as well as DET education and religious institutions. Finally, Maponya is introduced, with his political inclinations and his views on art, together with the issue of theatricality in his plays. Chapter two initiates the proposed critical analysis with a focus on The Hungry Earth. The focus is on Theatre of Commitment and the background events that inspired Maponya's response. Chapter three concerns itself with the critical analysis of Jika, "a play about the making of revolutionaries in South Africa ... and serves a political purpose - as a recording of pivotal moment in South African history ... " (Haysom, 1988: 1). An attempt is made to assess the extent to which the playwright has succeeded or failed to strike a chord harmonious with the pronouncements quoted. Chapter four ends the critical analysis with the treatment of Gangsters. Here an observation is made on the fusing of the three personas, namely Rasechaba, Biko and Maponya, into one symbolic whole representing the image of Jesus Christ on the cross - the Saviour who sacrificed His life for the salvation of sinners. Maponya is seen to have sacrificed his time and energy for the liberation of the downtrodden. The conclusion summarizes the study by placing the selected works in their suitable perspective in respect of the notion of Commitment in literature, with particular reference to theatre. Maponya is seen to have played a commendable role in the liberation of his peoples' minds by teaching them the business of organizing revolutions, as well as by championing the liberation struggle.
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  • Date Issued: 1998

Student teachers' conceptualisations of 'significant' animals

  • Authors: Murtough, Neil
  • Date: 1997
  • Subjects: Environmental education -- South Africa Teachers -- Training of -- South Africa Human-animal relationships -- South Africa -- Folklore Zoology -- South Africa -- Folklore
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1775 , http://hdl.handle.net/10962/d1003660
  • Description: Constructivist approaches to teaching and learning are a well established component of the landscape of educational research, especially in Science education. This research took as its starting point the limited amount of social constructivist research available in the field of Environmental Education and responded to calls for further research. The research was designed within an interpretive tradition, as a critically phenomenological enquiry employing two methods; single case studies and a focus group. Data collection used progressively focused interview questions to proceed through a series of individual interview stages, starting with a simple description of conceptualisations and moving to deeper analysis of influences on, and use of conceptualisations. The focus group was designed as a forum to explore the pedagogic issues connected to the 'social negotiation of learning', based on data and insights gained from earlier interview stages. The goals of the study were to record data on the conceptualisations of animals perceived as significant by a group of Tsonga speaking students, and to seek insights into the formative influences on those conceptualisations. The research question, namely what contribution can social constructivist approaches to teaching and learning make to Environmental Education? guided an interpretation of the above data in terms of a range of social constructivist theories of learning. Theories of Radical and Social Constructivism as applied in Science education, although dominant orientations for educational research in constructivist learning, were challenged and found inappropriate as a basis to inform methodologies for Environmental Education. Instead Lave's (cited in O'Loughlin, 1992) socio-cultural approach to learning was explored as the basis to create a more useful perspective on an environmental education situation. Finally it was concluded that Lave's socio-cultural approach to learning may be a useful guide to helping a teacher- elicit the full range of conceptualisations present in an environmental education situation, but is not ultimately effective if no challenge and change comes about. Consequently, a socially critical constructivist teaching and learning approach was suggested In conclusion I commented on the interpretive research methodology employed and suggested an example of a socially critical methodology that could take this investigation further.
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  • Date Issued: 1997

Arguments for other minds

  • Authors: Dowling, Dolina Sylvia
  • Date: 1989
  • Subjects: Mind and body -- Philosophy
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:2702 , http://hdl.handle.net/10962/d1001977
  • Description: If I am aware of my own mental states by introspection (a) How can I know that other people have minds? and (b) How can I know what their mental states are? These are two of the questions with which I will be concerned in this dissertation. I discuss five different attempts to deal with them. (i) The claim that we can know that other people have minds by an argument from analogy. I show a number of serious flaws in Russell's and other versions of this argument. (ii) Malcolm's thesis that the criteria by which we apply mental terms to others are just different from the criteria one applies in one's own case. I argue that Halcolm's accounts of both first- and third-person criteria are not adequate. (iii) I consider Strawson claim that 'persons' is a primitive concept and that behavioural criteria are "logically adequate" for determining the correctness of statements about the mental states of others. I argue that both of his key concepts are underanalysed. (iv) A quite different attempt to answer our questions (a) and (b) is given by the empirical realist who argues that knowledge claims about other minds are best understood as hypotheses in a wider psycho-physical theory. I show that the major fault in Putnam's version of empirical realism is that he overlooks the subjective character of (iii) our mental states. (v) Finally I consider the claim, due to Nagel, that a conception of mental states is possible which incorporates both subjective and objective aspects of the phenonemon. I speculate that with a great deal of development this approach might hold the answer to our questions.
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  • Date Issued: 1989

The selection and evaluation of grey-level thresholds applied to digital images

  • Authors: Brink, Anton David
  • Date: 1988
  • Subjects: Image processing -- Digital techniques
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5443 , http://hdl.handle.net/10962/d1001996
  • Description: Many applications of image processing require the initial segmentation of the image by means of grey-level thresholding. In this thesis, the problems of automatic threshold selection and evaluation are addressed in order to find a universally applicable thresholding method. Three previously proposed threshold selection techniques are investigated, and two new methods are introduced. The results of applying these methods to several different images are evaluated using two threshold evaluation techniques, one subjective and one quantitative. It is found that no threshold selection technique is universally acceptable, as different methods work best with different images and applications
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  • Date Issued: 1988

The acquisition of reading skills in English by coloured primary school children whose home language is Afrikaans : a developmental study conducted in a specific South African community

  • Authors: Pitt, Joe Harrison
  • Date: 1987
  • Subjects: Reading (Primary) -- South Africa Reading (Elementary) -- South Africa English language -- Study and teaching (Primary) -- Afrikaans speakers English language -- Study and teaching -- South Africa -- Foreign speakers
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2338 , http://hdl.handle.net/10962/d1002020
  • Description: This research studies the acquisition and development of specific reading skills in English by "Coloured" primary school children for whom English is a second language. This study involves both oral and silent reading research. Developmental trends in both modes of reading are compared with those established for reading in Afrikaans in order to ascertain whether any transfer takes place from Afrikaans to English. For analysis of data obtained from oral reading, this researcher adopted an error analysis method devised by Kenneth Goodman (1973), viz. Miscue Analysis (MA). Readers read a passage and their miscues were recorded. From the miscues this researcher established, for the different standards: the frequencies of miscues; readers' ability to associate sound and symbol; sensitivity to grammar; meaning access; and correction strategies. In the silent reading research, readers' performances in a test battery of eight sub-tests provide insights into the presence or absence of information processing skills. Readability levels (Singer and Donlan (1980), discrimination index and facility value (Heaton 1975), and Chi-Square Statistics (Roscoe 1969) determine the development of specific reading skills, viz.: utilization of textual cues; understanding cause and effect relationships and sequence; previewing and anticipation; scanning, referring and synthesizing; understanding text structure and coherence; understanding propositional development; understanding synonymy and antonimy; and understanding communicative value. Grellet (1981), Kennedy (1981), and Harri-Augstein (1982), inter alia, regard these skills as crucial to efficient text processing. Analyses of data show there are developmental patterns, but skills emerge 1 - 3 years late when compared with results obtained by Kennedy (1981 ) and develop at a retarded and erratic pace. The readers in all the standards have not mastered the skills sufficiently to process text efficiently. This research shows that Std 3 is a cut-off level where a transition takes place from lower-order to higher-order skills processing. In addition, Chi-Square Statistics show little transfer from Afrikaans to English; the skills develop independently in the two languages. Enquiry has identified various factors that influence skills deficiencies, viz.: syllabus prescriptions and problems of interpretation; teachers' understanding of the reading process and the methods employed; teacher-training progresses; materials prescribed for reading; and reading in the society. This research recommends ways in which short comings can be remedied
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  • Date Issued: 1987

An analytical study of narrative techniques in Giono's Regain

  • Authors: Abel, Hermione
  • Date: 1986
  • Subjects: French fiction , Novels , Criticism , Symbolism , Regain , Giono, Jean, 1895-1970 -- Criticism and interpretation
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:3561 , http://hdl.handle.net/10962/d1002008
  • Description: The dominant theme in Regain is that of death leading to rebirth. This dissertation attempts to explore Giono's narrative techniques within this context. No single chapter will be devoted to a specific technique; instead, the various devices used by the author are discussed as they emerge from the structure of the chapters. Justifying the field of study as defined in the "Introduction", the following three chapters outline the passage of life from death to eventual rebirth. With acknowledgement to Frank Kermode, who writes: "A concord of past, present and future three dreams which, as Augustine said, cross in our minds, as in the present of things past, the present of things present, and the present of things future" ¹, the first three chapters bear his terminology for their headings. Chapter One, "The Present of Things Past", deals with Mameche's loss of her husband and son. Chapter Two, "The Present of Things Present", focuses upon Mameche' s realization of Gaubert's departure, and the decision that she must do something to save the dying village of Aubignane. Chapter Three, "The Present of Things Future", sees Mameche setting out in search of a wife for Panturle, and succeeding. This brings to an end Part One of the novel. Interwoven throughout the chapters are paradigms from Greek mythology, rich in universal symbolism, and the author's belief in man's ability to fuse himself with his surroundings. The conclusion summarizes the findings of this study, attempting to show how an analysis of Giono's narrative technique provides an insight into such a novel as Regain. ¹The Sense of an Ending (London: Oxford University Press, 1966), rpt., 1970, p. 50.
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  • Date Issued: 1986

A preliminary validity study of the Rathus Assertiveness Schedule with a sample of the South African university population

  • Authors: Dares, Anna Ewa
  • Date: 1981
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:21178 , http://hdl.handle.net/10962/6771
  • Description: The study investigated the validity of the Rathus Assertiveness Schedule (RAS) with a sample (N=l68) of the white South African undergraduate students. In terms of criterion- related validity, results indicated that ratings of external judges, unaware of their subjects' self-evaluation, correlated significantly with the assertiveness scores of the male subjects only. Construct validation of the RAS with ten personality traits measured by the Howarth Personality Questionnaire yielded results consistent with Wolpe's hypothesis that assertiveness relates inversely to anxiety. In addition, evidence was found to support the contention that assertiveness correlates negatively with inferiority. A principal components analysis of the RAS revealed a potentially useful factor structure for both males and females. A number of factors including situation-specific assertive behavior as well as factors measuring aggressiveness were identified for both sexes.
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  • Date Issued: 1981

Un' analisi del personaggio femminile in alcune tragedie di Vittorio Alfieri

Xhosa-English pronunciation in the south-east Cape

  • Authors: Hundleby, C E
  • Date: 1965
  • Subjects: Xhosa language -- Pronunciation by foreign speakers English language -- Pronunciation by foreign speakers
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:2303 , http://hdl.handle.net/10962/d1012467
  • Description: The thesis mainly concerns itself with an analysis of the present day pronunciation of Xhosa-English. The isolation and identification of the segmental phonemes and the phonemes of stress, intonation and transition form the core of the work. The author has attempted to give continuity by introducing a subsidiary theme, the Lado hypothesis as stated on page 1. In conformity with the the methodology imposed by the Lado formula, it was first necessary to establish two things: first, a standard background against which the characteristics of XEP could be compared, and secondly, to give briefly, but in sufficient detail for our purpose, the main phonological features of the mother tongue.
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  • Date Issued: 1965
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