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Amohelang

Amohelang

An analysis of the relationship between the sources of conflict and the stages in the conflict process within the marketing channel comprising retail pharmacy managers and medical doctors

  • Authors: Futter, William Thomas
  • Date: 1988
  • Subjects: Medicine -- Formulae, receipts, prescriptions -- Marketing , Marketing channels , Marketing research , Drugs -- Marketing
  • Language: English
  • Type: Thesis , Masters , MCom
  • Identifier: vital:1161 , http://hdl.handle.net/10962/d1001628
  • Description: Marketing channels have traditionally been examined as commercial conduits the sale objective of which was to facilitate the flow of goods from producer to consumer. This approach emphasized functional and structural aspects of the channel and was primarily concerned with the efficiency of the distribution system. During the last two decades, marketing channels have increasingly been viewed as social systems affected by the behavioural dimensions of power, conflict, roles and communication. The rapid growth of vertical marketing systems with greater authority and interdependence between channel members, have stimulated interest in this field. Nevertheless, research has been limited and characterized by methodological problems and conceptual differences about the definitions of behavioural variables and their relationships. Some attempts have been made to develop an integrated framework within which to conduct research into channel relationships, but the validity and relaibility of these models has not been tested. This research project examined the relationship between the sources of conflict and stages in the conflict process. The sources of conflict were subdivided into attitudinal and structural categories, the latter being concerned with goal differences, the desire for autonomy in the face of interdependence and competition for scarce resources. The conflict process model adopted by the author assumes the existence of stages of latency, feeling, perception, manifestation and aftermath in each conflict episode. The first four were treated as separate behavioural states for which different levels of conflict intensity were measured. In order to provide greater explanatory power to the results of the analysis, the perceptions of two respondent groups were identified, namely the leader group, consisting of channel members responsible for the overall strategic interests of the channel, and the affected group, consisting of channel members who had been adversly affected by the activities of their partners in the channel dyad. In addition, respondents were asked to identify separately, their perceptions of the macro and micro levels of conflict in the four conflict states. The marketing channel for prescription medicines was selected for the study. The focal dyad consisted of retail pharmacy managers and doctors with single respondent perceptual measures being obtained from the retail pharmacy managers. A mail survey of all the retail pharmacy managers in South Africa, South West Africa/Namibia, and the independent homelands conducted in July 1987 resulted in a 40% response rate (1031 returns). Tests indicated statistically significant differences between the perceptual measures representing the sources and stages of conflict, the macro and micro levels of the stages of conflict and between the leader and the non-leader groups and the affected and non-affected groups. A sequential hierarchy in the level of conflict measured in the behavioural states was indicated, with decreasing levels of conflict being identified in states of latency, perception, feeling and manifestations, respectively. An analysis of the results revealed that attitudinal sources of conflict were more important that structural sources in measures of perceptions, feelings and manifestations of conflict behaviour. In the latent conflict state, structural sources assumed greater importance than attitudinal sources. In most of the measures, the sources of conflict were more correlated with perceptions of conflict at the macro level than the micro level. The exception was manifest conflict for which micro conflict levels were more important. The major sources of conflict were differences in perceptions, differences in goals and the lack of autonomy. The leader group indicated a particular concern for attitudinal factors, particularly communication difficulties. The affected group, whilst identifying attitudinal factors as being the most important, was especially concerned with their lack of autonomy from the doctor, rather than the competition for scarce resources which could have been expected. An overall assessment of the level of conflict between retail pharmacy managers and doctors indicated that the channel dyad was relatively free from conflict. Relationships were characterized by a degree of satisfaction, some degree of harmony and little evidence of conflict behaviour.
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  • Date Issued: 1988

An analysis of the structural use of music, song and dance in certain novels by West African writers in relation to concepts of time

  • Authors: Baxter, Marion
  • Date: 1988
  • Subjects: Music and literature
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:2174 , http://hdl.handle.net/10962/d1001825
  • Description: The topic of this thesis is time in the West African novel in English and French, and the key approach is that West African time is readily grasped through a study of West African music. Though Western time is not exclusively or only linear, mechanical and exploitative, and African time not exclusively cyclic, synchronic and experiential, yet there is a characteristically African view of time and preferred modes of its employment in West African fiction. The novelists considered here wrote in European languages, yet each was a member of a specific cultural group and concerned to portray the aesthetics of his inheritance, an important aspect of which is the predominance of repetitive formulae, both in music and in oral literature. The Introduction offers an historical survey of some of the main notions of time that have been manifest in the West, and compares them with notions of African time. Chapter One examines the structural use of rhythm and repetition in the novels of Camara Laye. Chapter Two discusses the griot and other traditions of oral literature in the novels of Ayi Kwei Armah and Yambo Ouologuem, novels which are concerned with the griot 's continuing role in the creation and dissemination of historical perspective. Chapter Three analyses Chinua Achebe 's portrayal of the values of pre-colonial life in Igbo society where the role of music is to limit behaviour through the structures of ritual which thus create static/cyclic time. Chapter Four describes the syncretic art-form, 'highlife', as used by novelists such as Wole Soyinka, which, because it is transitory and always changing, underscores the ironies of modern city life. The thesis concludes that the authors discussed above are aware that music, because it is predominantly social in Africa, is a powerful medium for achieving a healing synthesis between the traditional past when communalistic values were binding, and the urban-orientated present with its insistence on individuation and material enrichment.
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  • Date Issued: 1988

An approach to the urban history of early Victorian Grahamstown, 1832-53, with particular reference to the interiors and material culture of domestic dwellings

  • Authors: Scott, Patricia Elena
  • Date: 1988
  • Subjects: Interior decoration -- Grahamstown -- History , Housing -- South Africa -- Grahamstown -- History , Grahamstown (South Africa) -- History
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:2555 , http://hdl.handle.net/10962/d1002408 , Interior decoration -- Grahamstown -- History , Housing -- South Africa -- Grahamstown -- History , Grahamstown (South Africa) -- History
  • Description: This study is a venture in urban history in that although housing has been the subject of a number of recent studies, little attempt has been made within the British urban history framework to give serious study to what lies behind the architectural facade, the material domestic culture of an urban community. An important objective of this study is to examine the material culture of domestic dwellings in early Victorian Grahamstown, also referring to other parts of the Cape Colony. Where possible these facts are related to the occupants of the dwellings. No community, urban or rural, can be divorced from the influences which lie beyond its immediate locality in region or metropol. As a preliminary to this study the urban background of industrial Britain is examined, as are English and Dutch cultural influences on the interiors of Cape homes in general. The occupational stratification and spatial structure of early Victorian Grahamstown are then explored, leading into· a discussion of the material domestic culture of the interiors of Grahamstown dwellings. In the final analysis, this study is an attempt to uncover the character of early Victorian Grahamstown and its possible implications for English cultural influences at the Cape. In so doing, not only what constitutes the domestic material culture of Grahamstown is established, but beyond that, a comparison made with domestic material cultural developments in another colonial, though not frontier, settlement with roots in Georgian and Victorian England, namely Australia.
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  • Date Issued: 1988

An examination of the literary quality of two reading schemes

  • Authors: Waters, Nigel Bruce
  • Date: 1988
  • Subjects: Reading (Primary) , Reading -- Language experience approach , Readability (Literary style)
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1345 , http://hdl.handle.net/10962/d1001411
  • Description: Learning to read is one of the most crucial life tasks that the young child must acquire whilst in primary school. In modern society, much of what one does is dependant on having the ability to read. While a great deal of research has focused on how children learn to read, relatively little attention has been paid to the literary quality of the material the children are exposed to whilst learning to read. In the past few years I have become increasingly concerned with the number of teachers who use material designed for teaching children to read without being aware of the literary quality of the material. While numerous teachers are aware of the issues surrounding the learning to read debate and use up to date materials to teach reading, far too many accept the material supplied by the school without questioning its literary merit and its impact upon the young reader. This piece of research is an attempt to evaluate the literary quality of two reading schemes currently in use in Cape Education Department schools. The chief conclusion of the research is that the schemes examined fall far short of the standards required for them to be considered good literature. Although the research is limited to two reading schemes, it is hoped that a teacher using other schemes could use the framework supplied in this study to examine the literary quality of the material she is using. Furthermore, the final chapter offers suggestions as to how to replace material of poor literary quality with books of a higher literary standard. On the basis of the above findings it is suggested that there is a need for individual teachers, schools, teacher training institutions and the Cape Education Department to examine the literary quality of reading schemes and books that are used in the process of teaching children to read. It is hoped that this piece of research will create a greater awareness amongst teachers of the literary quality of reading materials and prompt further research into such materials that will be of benefit to the central character in this study; the young child learning to read
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  • Date Issued: 1988

An existential phenomenological study of gaining insight into oneself through perceiving another person

  • Authors: Hoek, Trevor Martin
  • Date: 1988
  • Subjects: Self Self-perception
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:3113 , http://hdl.handle.net/10962/d1004594
  • Description: The aim of this study was to examine the structure of the experience of gaining insight into oneself through perceiving another person. Such a one-to-one situation was selected in order to ensure a minimal level of complexity. The researcher conducted a pilot study in order to check whether people could relate such an experience in response to a long and difficult interview question. One female first year student responded from among a group of thirty to whom the question was posed. She was then interviewed. The data appeared acceptable. This was confirmed after the data analysis using the phenomenological-psychological method of textual analysis. The analysis showed that the subject, while comparing herself with the person whom she was with, discovered that she structured her life too rigidly in her attempt to meet the expectations of others. This discovery gave her the opportunity to restructure her approach to her world and to the others whom she had seen in only a narrow and abstracted way. Lengthier interviews were then conducted with a further six potential subjects. These were then transcribed. Two of those subjects, though, were found to have experienced insight through perceiving more than one other person. The data from the four remaining subjects were then analysed using the phenomenological psychological method. The researcher discovered that insight involves a clarity of perception which is achieved when the person becomes aware of clearly differentiated possibilities; these are revealed to him through his intensely reflecting on where he stands in relation to the other person whom he perceives, or in relation to alternatives revealed to him by the other. The polarities that are revealed allow the person to take up a new approach to his world, since the person discovers that his experience has revealed that he has been inauthentic in his muddled concern about others, and this gives the person a perception of truth that he was previously unaware of. These findings were dialogued with the writing of psychologists and philosophers who have written on the subject of becoming aware of oneself in relation to others.
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  • Date Issued: 1988

An existential-phenomenological explication of the older person's perception of anticipated death

  • Authors: du Plessis, Christine Edna
  • Date: 1988
  • Subjects: Death -- Psychological aspects
  • Language: English
  • Type: Thesis , Masters , MSocSc
  • Identifier: vital:2905 , http://hdl.handle.net/10962/d1002070
  • Description: This study attempts to explore, both theoretically and empirically, death anxiety across the lifespan in Western society. Six elderly women between the ages of 75 and 90 years were interviewed about their current perceptions and attitudes toward their anticipated deaths, and to what extent these perceptions may have altered over the course of the life cycle. It was hypothesized that an acceptance of religion and a belief in an afterlife existence; a sense of having experienced death before, in seeing loved ones die; and a feeling of having lived a meaningful life through the reminiscence of past events would all facilitate an older person's acceptance of anticipated death. An existential phenomenological explication of the protocols revealed that: religion need not necessarily play a major role in this regard; both the life reminiscence process and having experienced death before in seeing loved ones die facilitated acceptance of death; older persons are prepared for death in the sense of experiencing a feeling that their life cycles have been completed; although death may not be feared, many fears of dying are prevalent. It was thus concluded from this study that, although death is not a major preoccupation of the older person, it does still play a significant role in the lives of the elderly in that being aware of impending death allows the older person to regulate her life according to ̕̕̕̕̕ʾtime-left-to-liveʾ
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  • Date Issued: 1988

An existential-phenomenological exploration of interracial love relationships in South Africa

  • Authors: Ross, Christopher James
  • Date: 1988
  • Subjects: Interpersonal relations -- South Africa , South Africa -- Race relations
  • Language: English
  • Type: text , Thesis , Masters , MA
  • Identifier: vital:2900 , http://hdl.handle.net/10962/d1002064
  • Description: The aim of the study was to explicate the experience of interracial love relationships between Blacks and Whites in South Africa. As a point of departure, a basic question was established which would elicit the actual experience of this phenomenon. The researcher conducted twelve interviews and chose the six psychologically richest accounts. The researcher then analysed in detail (using the phenomenological method) the resulting protocols comprising the interviews. The researcher then explicated the experience and discovered that interracial love was a historical process of going through a relationship over time. The subjects experienced a particular historical background in the face of which they felt unfulfilled which brought about the potential to search for authenticity in a particular way. The subjects were placed in a situation where interracial love became a possibility. The subjects saw the other as human and fell in love. A new horizon emerged and a learning experience, about themselves and the world, occurred. The element of conflict was always present which was exacerbated by the South African Apartheid system. Subjects experienced fulfillment and disappointment depending on whether or not their historical demand was met. This structure of the experience was dialogued with the writings of existential-phenomenological philosophers and psychologists and also with that of previous research in the context of discussing particular areas of psychological significance such as historical background and Apartheid, racism, alienation, motives for interracial love, love and the universality of human nature and interracial love as a learning experience.
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  • Date Issued: 1988

An integration of reduction and logic for programming languages

  • Authors: Wright, David A
  • Date: 1988
  • Subjects: Logic programming languages , Programming languages (Electronic computers)
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:4570 , http://hdl.handle.net/10962/d1002035
  • Description: A new declarative language is presented which captures the expressibility of both logic programming languages and functional languages. This is achieved by conditional graph rewriting, with full unification as the parameter passing mechanism. The syntax and semantics are described both formally and informally, and examples are offered to support the expressibility claim made above. The language design is of further interest due to its uniformity and the inclusion of a novel mechanism for type inference in the presence of derived type hierarchies
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  • Date Issued: 1988

An investigation into the role that knowledge of the nature of mathematics and other factors play in determining motivation for further study of mathematics after std 7 in selected provincial secondary schools

  • Authors: Arguile, David Ian
  • Date: 1988
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1352 , http://hdl.handle.net/10962/d1001418
  • Description: This study involves an investigation into reasons why pupils continue with mathematics after Std 7. The sample, consisting of Std 8 and Std 10 mathematics pupils at six academic, English-medium high schools in Port Elizabeth, had to complete a short questionnaire during the third term of 1985. It was found that most pupils continue with mathematics because of requirements for certain post-matric courses, to improve their career options and for other reasons classified in this investigation as "extrinsic", i.e. reasons that are not directly related to the nature of mathematics. An attempt is made to determine the extent of the pupils' knowledge of the nature of mathematics. Questions relating to the nature of mathematics are poorly answered by almost all of the pupils, thereby suggesting that this aspect of mathematics is sadly neglected in mathematics courses. The suggestion is made that this lack of knowledge of the nature of mathematics is linked to pupils' decisions to continue with the subject. The conclusion is drawn that unless more attention is given to conveying to pupils something of the nature of mathematics, there will be an increasing proportion of pupils who choose to continue with mathematics for the "wrong" reasons. This, in turn, has possible negative implications for mathematics education in general. Attention is also paid to differences re the above in respect of groupings based on standard, mathematical grade, sex, mathematical achievement and type of schooling. Although no conclusive findings are made other than with regard to specific questions, enough evidence of differences in certain of the groupings is produced to warrant further investigation
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  • Date Issued: 1988

An investigation of the sources and supply of coarse sediment input to a semi-arid channel reach

  • Authors: Frauenstein, Glenn Gavin
  • Date: 1988
  • Subjects: Sedimentation and deposition -- Arid regions
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:4803 , http://hdl.handle.net/10962/d1001903
  • Description: This study comprises an investigation of the source and supply of coarse sediment input to a semi-arid channel reach. Despite a growing body of lIterature documentIng research of various aspects of sediment response in semi-arId areas, few studies attempt to integrate processes active in specific source areas wIth sediment supply to the channel. Detailed In the present study is an account of the processes active in the study area, identifIcation of source environments, a discussion of some of the factors affecting supply, a comparison of the effectiveness of gravItatIonal and fluvIal supply processes and an estImatIon of the time sequence of sediment supply to and removal from a channel reach. The above aspects of sediment supply are embodied In the aims set for the study. The study is conceptualIsed withIn the framework of a coarse sedIment supply model. The model is formulated from supporting literature and tested in the light of the results obtained through an investigation of the above aspects of sediment supply in the specIfic study area. The model is prImarily a qualitative one and the data collected intended to strengthen the qualitative nature of the model, while at the same time add at least some measure of quantification. Several reasons for studyIng coarse sediment behavIour in semI-arid areas are identIfied and include the need to improve the present lack of understanding of the relatIonship between supply and removal of sediment, the temporal dIstributIon of sediment discharge and the relatIve contrIbutions of coarse sediment to the overall load of rivers. The study area is located within the semi-arid Ecca basin north-east of Grahamstown. A specifIc channel reach is chosen withIn a sub-catchment (catchment B) of the Ecca catchment area as it has a variety of channel bank environments, is accessible through the entire reach, and the proximity of a raingauge and flow measurIng weir provide the necessary hydrometeorological inputs. The methods of observing sediment response from five data collection sites Include the use of slope or bank base sediment traps, erosion pins, tracer particle monitoring. sequential photographic surveys, and channel bed surface profile surveys. Hydrometeorological data is provided by records drawn from the data bank at the Hydrological Research Unit. Rhodes University. All rainfall records as well as channel flow data are available in the form of continuous records. Rainfall amount and intensity for any period could be extracted from these records. Data collection is confined to a period of two years, during which time the study area was visited on an approximate monthly basis. The index of erosivity (EI₃₀) could also be calculated from the hydrometeorological records and has been used as an integrated measure of rainfall intensity over the monthly period between site visits. The results are presented on a sample day for sample day basis. The sediment response data together with hydrological data is represented graphically for each sample day, of which there were nineteen. Discussion and interpretation of the results is left to a separate chapter. The interpretation of the results are based largely upon graphical representation of data time series and of interrelationships between some of the variables measured. The limited number of sample days together with the assumed auto correlation present in much of the data precluded the use of simple statistical testing procedures. The use of more complex procedures is not considered worthwhile and is unlikely to add to the interpretation of the results. Bedrock weathering is found to be a fairly active producer of coarse sediment on exposed shale bedrock outcrops through which sections of the channel are cut. The transport of the weathered detritus to the channel is attributed to a combination of gravitational and fluvial transport processes, with each process dominating at different times, depending on the magnitude of the climatic input. A tentative comparison of the effectiveness of the two processes reveals that both are capable of transporting similar amounts of sediment but on different time scales. The trends of sediment supply from the various bank environments display remarkable similarity , suggesting a measure of consistency of response to climatic input through the entire reach. Source areas of coarse sediment identified were limited to a small percentage of the total valley area and consisted almost entirely of the immediate channel environment. A tributary gully appears to be an important source of coarse sediment during fluvially dominated supply episodes, while the channel banks supply sediment on a quasi-continuous basis. The total yields for each source environment were extrapolated from the sampled amounts, revealing that channel banks are the predominant source environments. An attempt is made to assess the role of various factors which might affect sediment supply. The factors include rainfall amount and intensity, channel flow, geology/lithology, dip of strata, aspect of channel banks and size of weathered material. The findings, though not conclusive, do give some indication of the role of the above factors. It is suggested though that this particular aspect of sediment supply receive further attention in future research. Discussion on the time sequence of supply to and removal from the channel draws attention to a pulse- like movement of sediment 'waves' through the channel, and two scales of removal-accumulation cycles are identified. Finally the validity of the model is assessed and with the exception of a tributary inflow process not envisaged in the original model, is found to be an accurate representation of sediment supply in semi-arid areas, in both its static and dynamic phases. The suggestion is offered that future research on the sediment supply system, in all climatic regimes, can be conceptualised within the context of the basic model proposed in the present study. Specific components of the model should be quantified by numerous individual research efforts, and in this way, serve to build up the model into a widely applicable tool with which to interpret sediment supply
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  • Date Issued: 1988

An investigation of the structure of the Southern Hemisphere radio-meteor streams

  • Authors: Roux, David Gerhardus
  • Date: 1988
  • Subjects: Radio meteorology -- Southern Hemisphere , Solar system
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5448 , http://hdl.handle.net/10962/d1004587 , Radio meteorology -- Southern Hemisphere , Solar system
  • Description: Our current knowledge of the Solar System, with a particular emphasis on the systems of interplanetary objects, is reviewed, and the theory of meteors and the reflection of radio waves from meteoric ionization is then discussed. A description of the meteor radar is given and a method of calibrating the antenna beam is developed. The main project comprises two parts: (a) A general survey of the radar echorate for 20 major and minor meteor streams and the sporadic meteor background, conducted from Grahamstown over the period 1986 April to 1988 January, is described. Definite shower activity was observed for all of the major and some of the minor showers. (b) Based on a scheme proposed by previous workers (Morton & Jones), a method of recovering meteor radiant distributions from the distribution of echo directions is developed. We devise a technique of compensating for possible distortions of the resulting radiant maps, which may arise due to the arisotropic antenna beam. This involves a system of echo-weighting. Radiant maps which showed considerably less distortion than those of the above workers were obtained without the weighting procedure. It is concluded that, although the method in its present form introduces spurious features into the maps, the principle is sound and should eventually be refined to produce the desired compensation
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  • Date Issued: 1988

Application of high-performance liquid chromatography for the analysis and pharmocokinetics of mephenoxalone

  • Authors: Van der Westhuizen, Fiona
  • Date: 1988 , 2013-03-06
  • Subjects: High performance liquid chromatography , Central nervous system depressants
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:3810 , http://hdl.handle.net/10962/d1004385 , High performance liquid chromatography , Central nervous system depressants
  • Description: Mephenoxalone is a mild central nervous system depressant with activity resembling that of meprobamate. Since its introduction in 1961 mephenoxalone has been used as an anxiolytic and as a muscle relaxant, although the latter effect is weak. Preliminary studies on the absorption and disposition of mephenoxalone have been conducted in beagle dogs but no pharmacokinetic data from human studies have been reported, except for a single study in which the biotransformation products present in human urine were identified. Methods presently available for the determination of mephenoxalone in biological fluids lack the sensitivity, specificity and precision required for detailed pharmacokinetic studies. In this study, a rapid, sensitive, precise reverse-phase high-performance liquid chromatographic method with ultraviolet detection at 200nm was employed for the determination of mephenoxalone in biological fluids. Serum and urine samples were prepared for chromatographic analysis using simple liquid-liquid extraction techniques. The application of the assay to pharmacokinetic studies in humans is presented. After administration of a single oral dose of 400mg mephenoxalone dispersed in 150ml water to six young, healthy volunteers, the compound was rapidly absorbed with the peak concentration of 8μg/ml occurring after about 1 hour. The elimination half-life was approximately 3 hours. The drug was extensively metabolized with only about 1 percent of the administered dose being excreted unchanged in the urine after 24 hours. The bioavailability of a newly developed mephenoxalone-containing tablet was also investigated. The drug was absorbed more rapidly from the tablet than from the dispersed dose. This was attributed to a shorter in vivo dissolution time on the basis of in vitro tests, but this effect is not expected to be clinically significant. In addition, two human urinary metabolites of mephenoxalone were identified as unconjugated hydroxylated derivatives using thermospray HPLC-mass spectrometry. The plasma protein-binding properties of mephenoxalone were also investigated.
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  • Date Issued: 1988

Application of high-performance liquid chromatography to the analysis, stability and pharmacokinetics of erythromycin

  • Authors: Stubbs, Christopher
  • Date: 1988
  • Subjects: Erythromycin High performance liquid chromatography
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3809 , http://hdl.handle.net/10962/d1004372
  • Description: Erythromycin is a macrolide antibiotic used mainly in the treatment of infections caused by gram-positive organisms. Erythromycin base is rap idly degraded in acidic media necessitating the use of structurally modified erythromycin derivatives or acid resistant dosage forms in order to decrease gastric inactivation of the drug. The majority of pharmacokinetic studies to-date have utilized relatively non-specific microbiological assay procedures which are unable to differentiate between concentrations of active erythromycin base and the inactive pro-drug derivatives. A high-performance liquid chromatographic (HPLC) technique is described for the simultaneous determination of erythromycin base and propionate (inactive pro-drug form) in human serum and urine following the oral administration of erythromycin estolate, an acid stable derivative of erythromycin. The method involves a solid-phase extraction step prior to chromatography on a C18 reversed-phase column with coulometric electrochemical detection. Sample handling and storage techniques are presented which minimize hydrolysis of the inactive ester moiety between sample collection and analysis, thereby more accurately reflecting the in vivo situation than in previously published studies. Results from single dose pharmacokinetic studies indicate that only 10-15% of the total erythromycin concentration in vivo is present as the active base component following oral administration of erythromycin estolate. This percentage increases to approximately 25% during multiple dose administration. Novel urinary excretion data are presented which reveal that approximately 40% and 55% of the total erythromycin excreted in urine is excreted as erythromycin base following single and multiple dosages respectively. Computer fitting of mean serum concentration-time data revealed that an open one compartment model with linear first order absorption and elimination best described the absorption and disposition of erythromycin, although poor computer fits for individual data sets were observed. Some evidence of non-linear elimination is presented utilizing both compartmental and non-compartmental pharmacokinetic techniques. Large intra-and inter-personal variability in erythromycin absorption and disposition was experienced which was evaluated in five subjects who each received one 500 mg erythromycin estolate tablet from the same batch, on three separate occasions. In addition. an HPLC method is described for the analysis of "total erythromycin" concentrations following erythromycin estolate administration which involves hydrolysis of the ester component prior to chromatography. as well as an HPLC method utilizing amperometric electrochemical detection capable of monitoring the stability of erythromycin base in stored biological fluids. These methods were uti I ized in various stability studies involving erythromycin base and propionate as well as for the analysis of erythromycin estolate dosage forms.
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  • Date Issued: 1988

Art as an expression of the unconscious psyche

  • Authors: Weiner, Elana
  • Date: 1988
  • Subjects: Art -- Psychology , Art and mental illness , Art therapy , Subconsciousness
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: vital:3119 , http://hdl.handle.net/10962/d1004903 , Art -- Psychology , Art and mental illness , Art therapy , Subconsciousness
  • Description: This study aimed to investigate the use of expressive art as a manifestation of the unconscious psyche and as an indication of underlying personality dynamics. Its use as a significant medium for therapeutic encounter and exploration was investigated by analysing the art produced by four psychiatric in-patients during their participation in an eight-week art therapy programme. Each patient's art series was qualitatively and thematically interpreted with a focus upon the meaning of significant recurring images and motifs. The results of this study indicate that the particularity of each patient's graphic imagery enabled the lived experience of their struggles and preoccupations to emerge as uniquely different. Through their art productions they revealed the nature of their inner worlds and the power of their thoughts, feelings and experiences.
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  • Date Issued: 1988

Article by Ronald Atkins

Aspects of the biology and population dynamics of the geelbek Atractoscion aequidens (Cuvier) (Pisces: Sciaenidae) off the South African coast

  • Authors: Griffiths, Marc H
  • Date: 1988
  • Subjects: Sciaenidae -- South Africa Fish populations -- South Africa Atractoscion Atractoscion -- South Africa -- Ecology Atractoscion -- South Africa -- Physiology
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5194 , http://hdl.handle.net/10962/d1001970
  • Description: The geelbek Atractoscion aeguidens is an important commercial and recreational linefish species along the South African eastern seaboard . Aspects of its biology and population dynamics were investigated using data collected from various sampling sites along the South African east coast and from catch statistics obtained from both the Sea Fisheries Research Institute (Cape Town), and dealer records. The biological aspects studied included age and growth, reproduction and feeding. It was established that A. aeguidens is a fast growing species with a relatively late age at sexual maturity and a 1:1 sex ratio. Feeding studies revealed that it has become specialized to feed on small pelagic fish. The South African geelbek stock consists of three distinct age related sub-populations, each representing a particular phase in the life cycle. The sub-adults (1-4 yrs) occur in the South West Cape and feed predominantly on anchovy, Engraulis capensis, which they follow, moving inshore in summer and offshore in winter. The adults (5-9 yrs) undergo a seasonal inshore migration to Natal where they spawn in spring. The dynamics of this migration are strongly influenced by the annual movement of their principal prey viz. , Sardinops ocellatus, to that region. As a result the geelbek first arrive in Natal during mid winter. Evidence is also presented to suggest that a significant number of "adolescent " fish (4-5 yrs) undergo limited gonad maturation and a partial migration to at least as far as the South East Cape. Spawning appears to occur offshore. It is postulated that eggs and larvae are transported southwards by the peripheral waters of the Agulhas Current. After spawning the adults probably remain offshore and use the current to aid their return to the South and South West Cape, where they spend summer feeding on the Agulhas Bank. Juveniles (<1 yr) first appear in the South East Cape between January and March. They apparently use this region as a nursery area for almost a year before moving southwards to join the sub-adults in the South West Cape. In the South East Cape, the juveniles feed initially on mysids whereafter they switch to anchovies and pilchards. A preliminary stock assessment using yield per recruit and spawner biomass per recruit models, indicated that despite the current legislation the South African geelbek population is already overexploited. This is largely attributed to high rates of fishing mortality of the migratory adult population. Further management recommendations are therefore proposed. These include a size limit (660 mm FL), derived from an investigation of the interrelationship between natural mortality and somatic growth in a theoretical unexploited cohort, as well as a uniform bag limit for all user groups (5 fish per person per day)
  • Full Text:
  • Date Issued: 1988

Aspects of the biology of the musselcracker, Sparodon Durbanensis, and the bronze bream, Pachymetopon grande, (Pisces : Sparidae), with notes on the Eastern Cape recreational rock-angling and spear fisheries

  • Authors: Clarke, John Ross
  • Date: 1988
  • Subjects: Sparidea -- South Africa Sparodon Durbanensis Bream fishing
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5190 , http://hdl.handle.net/10962/d1001966
  • Description: The musselcracker, Soarodon durbanensis, and the bronze bream, Pachymetopon arande, are important components of rock-angling and spearfishing catches In the Eastern Cape. Aspects of their biology, including age and growth, reproduction, nursery areas and feeding, were Investigated to provide a basis for the rational exploitation of the resource. Both species are slow-growing and long-lived. Growth in S. durbanensls was described by the von Bertalanffy growth equation: Lt(mm) = 1021.2(1-e⁻°.°⁹°°⁽t ⁻° .⁷°⁹⁾). The von Bertalanffy growth model did not describe the total data set in P. grande, but by excluding the zero and one year old fish the data were described by: Lt(mm) = 461.1(1-e⁻°.¹⁵³⁽t ⁺¹.⁶⁴°⁾). Detailed histological examination of gonadal development showed that S. durbanensis and P. grande are rudimentary hermaphrodites. Both species had restricted breeding seasons which coincided with peak exploitation. Results indicated that both species are group spawners with pelagic eggs. Size at 50% maturity in S. durbanensis and P. grande was determined at 350 and 300mm fork length, respectively, corresponding to ages of 4.5 and 5.5 years. Intertidal pools functioned as nursery areas for S. durbanensis during the first year, whereas subtidal waters were more important for larger juveniles. P. grande juveniles were commonly observed on subtidal weed beds to a depth of 10m. A size-related change in the diet of S. durbanensis was observed. The juveniles were omnivorous, feeding predominantly on gastropods, echinoids and chlorophytes. The adults fed on a variety of large, reef-associated invertebrates. P. grande were omnivorous, with macroalgae being the principal dietary component. This species appears to utilise the storage and extracellular carbohydrates of the macroalgae. Results showed that macroalgal degradation by gut endosymbionts and the utilisation of macroalgal epibionts does not appear to occur in this species. A detailed analysis of catch composition and catch per unit of effort In the Port Elizabeth rock-angling fishery and the Eastern Cape spearfishery emphasised the recreational importance of S. durbanensis and P. grande. The localised distribution, slow growth and late maturation in both species results in their being susceptible to over-exploitation in these size-selective fisheries. Current legislation protecting these fish is discussed in relation to the findings of this study and additional management measures are proposed.
  • Full Text:
  • Date Issued: 1988

Aspects of the transdermal permeation and analysis of betamethasone 17-valerate

  • Authors: Smith, Eric W
  • Date: 1988
  • Subjects: Transdermal medication Skin absorption Dermatologic agents
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3815 , http://hdl.handle.net/10962/d1004741
  • Description: The current world-wide interest in transdermal drug delivery makes the prospect of valid in vitro diffusion cell methodology highly attractive. A new laboratory diffusion cell has been designed and constructed based on theoretical principles and practical permeation reports surveyed in recent literature, and has been applied to the monitoring of betamethasone 17-valerate permeation. The cell performance has been validated with respect to hydrodynamic mixing efficiency and temperature of the receptor phase. The steady-state permeation of this corticosteroid has been monitored through various synthetic and animal membranes in order to select the most appropriate media for in vitro study. The permeation of betamethasone 17-valerate has been monitored from various types of commercial and extemporaneously prepared semisolid topical formulation (cream, lotion, ointment and scalp application), through silicone membrane, human and weanling pig stratum corneum, and full thickness hairless mouse skin, and these in vitro results have been compared to data from in vivo blanching assays, using the same formulations, in an attempt to correlate the findings. This experimental methodology has necessitated the development of ancillary analytical techniques. A column-switching high-performance liquid chromatographic method has been developed for the rapid on-line clean-up and analysis of betamethasone 17-valerate contained in the various topical formulations, which minimizes sample handling and extraction procedures. The method has been modified for the analysis of this corticosteroid in the isopropyl myristate receptor phase used in the in vitro permeation experiments, and scintillation counting of tritium-labelled water has been used to verify the integrity of the animal membranes. The comparison of in vitro permeation and in vivo blanching results indicate good correlation of the data in certain instances. The closest correlations have been observed when the human stratum corneum has been used in vitro and these results are compared to data from the occluded mode of the blanching assay. The results of the porcine and murine media have also correlated with the human in vivo data, whereas the silicone membrane appears applicable only in certain in vitro experiments. The results indicate that valid, comparative percutaneous absorption data may be obtained in vitro by using a well designed, validated diffusion cell system.
  • Full Text:
  • Date Issued: 1988
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