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Indigenous Knowledge on Birthing Practices and the Use of Uterotonic Medicinal Plants to Prevent and Treat Postpartum Haemorrhage: A Mixed Methods Approach

  • Authors: Kovane, Gaotswake Patience
  • Date: 2020
  • Subjects: Medicinal plants Uterine hemorrhage
  • Language: English
  • Type: Thesis , Doctoral , PhD (Nursing)
  • Identifier: http://hdl.handle.net/10353/11385 , vital:39067
  • Description: There is a dearth of publications on women’s use of TMPs during the perinatal period. (Nergard et al., 2015). It is recommended that “plants used by pregnant women need to be better known in order to ensure that pregnant women receive effective treatment, to identify potentially unsafe use, and also to preserve valuable information about medicinal plants for women’s reproductive health for the future” (Nergard et al., 2015). Tripathi, Stanton and Anderson (2013:16) conclude that “[f]urther research is needed on the uterotonic efficacy of traditional preparations and on interventions to address the use [of TMPs] during labour”. Gruber and O’Brien (2011:218) support the statement and argue that the search for a “novel cyclotide-producing plant…may eventually lead to the development of novel uterotonic …drugs”. Pharmacological evidence of TMPs may promote the safe use of TMPs by IKHs during birth and the postpartum period. Kaingu, Oduma and Kanui (2011:495) emphasized that TBAs still have a crucial role to play in society, by assisting labouring women in rural communities and their “knowledge on medicinal plants is equally important and should be preserved for posterity”.
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  • Date Issued: 2020

Understanding rape perpetration: social origins and enactment

  • Authors: Malahle, Bongani
  • Date: 2019
  • Subjects: Rape -- Psychological aspects -- South Africa , Sex crimes -- Psychological aspects -- South Africa Women -- Crimes against -- South Africa Cognitive therapy
  • Language: English
  • Type: Thesis , Masters , MA
  • Identifier: http://hdl.handle.net/10948/40834 , vital:36241
  • Description: In South Africa rates of rape perpetration remain high despite efforts to prevent such violence. Globally, violence (including rape perpetration) has been declared a public health concern by governments and policy makers. This provided impetus for large epidemiological studies that has documented a number of risk factors for perpetration. However, despite these efforts, there are still large gaps in our understanding of rape perpetration, because studies often focus on risk factors rather than the dynamics of rape perpetration. Despite the significant quantitative descriptions of perpetration, there are still aspects which are not well understood, such as the interplay of social constructions and other factors during the actual act of perpetration. It has been suggested that rape can only be understood by engaging perpetrators and that such investigations can inform positive interventions in dealing with rape perpetration. The present study explored and described the origins of reasons for perpetration (subjective meanings and social constructs) and how these reasons interplay with other factors during the enactment of rape in South Africa. The data was purposively collected from seven incarcerated rape perpetrators from a correctional facility close to a major metropolitan area using semi-structured interviews. Data was analysed using interpretative phenomenological analysis. Social Cognitive Learning Theory was used as the main theoretical framework to contextualise the results. Some of the findings in the present study include solipsism and sexual solipsism as reasons, patriarchy and hegemonic masculinity as influential in the social origins, and moral dysregulation as a one of the tools to effect enactment of rape perpetration. Some of the recommendations include employing more psychological workers in the primary health care sector. Furthermore, continued engagement of males by NGO’s, NPO’s, school-based programmes, and community activism to combat the narratives that lead to moral disengagement is recommended.
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  • Date Issued: 2019

A longitudinal investigation into employability : student transition and experiences from tertiary education into the labour market

  • Authors: Harry, Tinashe Timothy
  • Date: 2018
  • Subjects: Employability Graduate students Labor market
  • Language: English
  • Type: Thesis , Doctoral , DCom
  • Identifier: http://hdl.handle.net/10353/11053 , vital:37015
  • Description: Orientation: Several policies have been formulated by the government to redress the inequalities of apartheid. However, the policies have not yielded any positive results as many graduates from Historically Disadvantaged Institutes (HDIs) continue to struggle in the open labour market as compared to graduates from Historically Advantaged Institutes (HAIs). This has been mainly attributed to the legacy of apartheid in several previous studies. As a result, most of these previously disadvantaged individuals (mostly Black Africans) struggle to make the transition from higher education into the world of work. Research Purpose: This study thus explores the journeys of these Black African students from HDIs to understand the transition and experiences from tertiary education into the labour market. Further, the research sought to understand how these transitions and experiences manifest in a context of high unemployment. Finally, the resolution tactics used by students in such a context are given attention. Research approach, design and method: A longitudinal qualitative approach was deemed appropriate for the study as the aim was to understand the changes that occurred over time. The data was collected over a two-year period. A narrative inquiry was utilized as it allowed the participants to share their perceptions without limitations. A total of 30 participants partook in the study. The participants were selected using a purposive sampling to ensure the right participants were involved in the study. The main criteria for selection to participate was that the participants had to be enrolled with a HDI. Main findings: The narratives of the participants led to the formulation of six main themes that were regarded as affecting the transitions and experiences of the Black graduates from HDIs; namely, (1) socio-economic background, (2) education system, (3) labour market experiences, (4) geographical location, (5) social capital and (6) student resolutions to the challenges of employability. A previously disadvantaged background resulted in the participants being recipients of poor education quality, no social networks or information to navigate the labour market and limited access to the labour market due to secluded residential areas. Subsequently, most participants were unable to take responsibility of enhancing their own employability. Contribution: It is not the sole responsibility of the higher education institutes to produce employable graduates, but it's a process that should also involve government, students and employers. As long as the social inequality remains an issue in the country all the efforts to improve employability and transition into the open labour market will be in vain. Furthermore, employers must work together with higher education institutes by offering programs such as internships and career expos to enhance the employability of the graduates. A Graduate Transition Model (GTM) is suggested based on the findings of this research.
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  • Date Issued: 2018

Molecular characterization of Mycobacterium bovis isolated from cattle and sputum specimens from humans in the Eastern Cape province, South Africa : public health and economic implication

  • Authors: Bhembe, Nolwazi Londiwe
  • Date: 2016
  • Subjects: Mycobacterium tuberculosis -- South Africa -- Eastern Cape Public health -- South Africa -- Eastern Cape
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: http://hdl.handle.net/10353/13238 , vital:39625
  • Description: Tuberculosis (TB) is a disease caused by the members of the Mycobacterium tuberculosis complex (MTBC), which infects both animals and humans. The primary host of Mycobacterium bovis is cattle. It remains a major global health problem. About 2 billion people are thought to be infected with TB and about 1.3 million decease each year from the disease. This study is aimed at determining the prevalence of the disease, characterizing the MTBC isolates and increasing the understanding of the genetic diversity MTBC in the Eastern Cape Province of South Africa, from studying both samples from both humans and cattle. A total of 376 cattle lymph nodes were collected from two commercial abattoirs for investigations. Suspected 6 000 sputum specimens were also collected from humans (cattle farmers). All collected samples were cultured, and isolates were confirmed with a multiplex polymerase chain reaction (PCR) targeting the mpb64 and IS6110 genes. Positive isolates were tested for resistance against anti-TB drugs using the standard Lowenstein Jensen proportion method. Isolates from cattle lymph nodes were further characterized to species level, using the region of deletion 1 (RD1) and oxyR restriction fragment length polymorphism analyses. MIRU-VNTR typing and spoligotyping assays were used to further examine the genetic diversity of all strains. Obtained spoligotype patterns were matched with isolates published in the universal spoligotyping database (SITVIT2). MTBC was detected in 162 (43.09 percent) cattle lymph nodes and 156 sputum specimens. Some isolates 25.9 percent (42/162) from the cattle lymph nodes samples were resistant to rifampicin (RIF) and 98.7 percent (154/156) were resistant to isoniazid (INH) and rifampicin (RIF) (of the human sputum specimens). All cattle lymph nodes isolates exhibited the RD1 gene, and the oxyR analyses classified 96.9 percent of the isolates as Mycobacterium tuberculosis complex and 3.1 percent as Mycobacterium bovis. Twenty seven spoligotype patterns were isolated from cattle lymph nodes, with 10 shared types (SIT) consigned to 5 lineages, including Bov_4-Caprea (1.9 percent), Microti (0.6 percent) and Beijing (17.9 percent) constituting East Asian, Latin-American-Mediterranean (LAM) (3.7 percent), X (4.3 percent), MANU (3.1percent), S (0.6 percent) and 67.9 percent were orphans that were further categorized to their designated lineages (Indo-Oceanic, Euro-American and West-African 2). Ninety one percent of the isolates from humans (farmers) were grouped into 7 clusters by spoligotyping, while the remaining 9 percent was unclustered. SITs were observed in 89.6 percent of the isolates from the Beijing, LAM, X, T and S families. The Beijing family was the most prevalent strain from both human isolates (77.2 percent) and cattle lymph nodes isolates (17.9 percent), and the T (0.6 percent) and Microti (0.6 percent) families were the least detected genotypes in both humans and cattle lymph nodes. In the cattle lymph nodes, spoligotyping showed a higher clustering rate of 82.1 percent, with the lowest (HGDI) = 0.485. The 12 MIRU-VNTR clustering rate was 64.8 percent, showing a higher HGDI of 0.671. However, a combination of both methods showed a decreased clustering rate of 53.7 percent; however these methods resulted in a higher HGDI (0.676). Isolates from human sputum specimens spoligotyping showed a higher clustering rate of 89 percent with an HGDI = 0.822. The 12 MIRU-VNTR showed the lowest clustering rate of 69 percent and an HGDI = 0.940 and the combination of the methods showed a clustering rate of 78 percent and an HGDI = 0.951. The results of this study show the diversity of MTBC strains in the Eastern Cape Province and the low clustering rate indicates continuing transmission in the province. The detection of MTBC strains from slaughtered cattle lymph nodes in abattoirs confirms the risk of providing TB infected meat in markets which has serious implications for the control of TB in South Africa. The continuing spread of MTBC in South Africa threatens both the public and economic health.
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  • Date Issued: 2016

Use of bioindicators and biomarkers to assess aquatic environmental contamination in selected urban wetlands in Uganda

  • Authors: Naigaga, Irene
  • Date: 2013
  • Subjects: Indicators (Biology) Biochemical markers Environmental monitoring -- Uganda Water quality biological assessment -- Uganda Water -- Pollution -- Uganda Wetlands -- Monitoring -- Uganda Wetland management -- Uganda Aquatic resources -- Uganda Aquatic resources conservation -- Uganda Aquatic resources -- Management -- Uganda Fishes -- Histopathaology -- Uganda Urban ecology (Biology) -- Uganda
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:5198 , http://hdl.handle.net/10962/d1002603
  • Description: Pollution of aquatic resources in Uganda is on the increase and the trends are expected to increase with increase in population size and urbanisation. Assessment and mitigation of the environmental impacts on water quality and biodiversity have now become necessary. The aim of the study was to integrate invertebrate and fish as bioindicators and fish histopathology as a biomarker in the assessment of water quality deterioration in urban wetlands in Uganda. The integration harnesses the advantages and counteracts the shortcomings of each method and thus builds a more robust diagnostic tool that gives a better view of the impacts to the entire ecosystem. Four endpoints which included, physicochemical variables, benthic macroinvertebrate bioindicators, fish bioindicators and fish histopathology biomarkers were compared between varied effluent-impacted wetlands (Murchison Bay in Kampala, and Kirinya, Masese and Winday Bay in Jinja) and a non-impacted reference wetland (Lwanika in Mayuge). Results from the effluent-impacted sites differed from the less impacted reference site. The two sampling locations at Murchison Bay (inshore and offshore) and one sampling location at Kirinya (inshore), that were highly impacted with urban effluent, showed elevated nutrient levels, low pH, dissolved oxygen and secchi depth readings. This corresponded with low invertebrate taxa and fish species diversity and richness; and severe histopathological responses in liver, gonads and gills of O. niloticus. Sensitive taxa such as ephemeroptera and trichoptera were completely absent while pollution tolerant taxa Chironomus sp, Corbicula and Oligochaeta were present. Also notable was the absence of many native haplochromines and presence of mainly Brycinus sadleri, Oreochromis niloticus and leucostictus. The organs manifested high prevalence of severe inflammatory and regressive changes and higher organ indices that fell within the pathological category. These sites were consistently classified as highly polluted under the four endpoints. The reference site was classified as least polluted while Masese and Winday Bay were moderately polluted. Results suggested that the approach of using invertebrate and fish as bioindicators and the fish histopathology as a biomarker, in relation to water quality physicochemical variables was a useful tool in highlighting the spatial differences in environmental quality.
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  • Date Issued: 2013

The isolation of muscle activity and ground reaction force patterns associated with postural control in four load manipulation tasks

  • Authors: Pettengell, Clare Louise
  • Date: 2010
  • Subjects: Physical fitness , Exercise , Materials handling , Manual work , Lifting and carrying
  • Language: English
  • Type: Thesis , Masters , MSc
  • Identifier: vital:5125 , http://hdl.handle.net/10962/d1005203 , Physical fitness , Exercise , Materials handling , Manual work , Lifting and carrying
  • Description: Although much effort has been placed into the reduction of risks associated with manual materials handling, risk of musculoskeletal disorder development remains high. This may be due to the additional muscle activity necessary for the maintenance of postural equilibrium during work tasks. This research proposes that postural control and subsequent additional muscle activity is influenced by the magnitude of the external load and the degree of body movement. The objective of this research was to identify whether performing tasks with increased external load and with a greater degree of trunk motion places additional strain on the musculoskeletal system in excess of that imposed by task demands. Twenty-four male and twenty-four female subjects performed four load manipulation tasks under three loading conditions (0.8kg, 1.6kg, and 4kg). Each task comprised of a static and dynamic condition. For the static condition, subjects maintained a stipulated posture for ten seconds. The dynamic condition required subjects to move and replace a box once every three seconds, such that a complete lift and lower cycle was performed in six seconds. Throughout task completion, muscle activity of six pairs of trunk muscles were analysed using surface electromyography. This was accompanied by data regarding ground reaction forces obtained through the use of a force platform. After the completion of each condition subjects were required to identify and rate body discomfort. Differential analysis was used to isolate the muscle activity and ground reaction forces attributed to increased external load and increased trunk movement. It was found that the heaviest loading conditions (4kg) resulted in significantly greater (p<0.05) muscle activation in the majority of muscles during all tasks investigated. The trend of muscle activity attributed to load was similar in all significantly altered muscles and activation was greatest in the heaviest loading condition. A degree of movement efficiency occurred in some muscles when manipulating loads of 0.8kg and 1.6kg. At greater loads, this did not occur suggesting that heavier loading conditions result in additional strain on the body in excess of that imposed by task demands. In manipulated data, trend of vertical ground reaction forces increased with increased load in all tasks. Sagittal movement of the centre of pressure attributed to load was significantly affected in manipulated data in the second movement phase of the “hip shoulder” task and the second movement phase of the “hip twist” task. The “hip reach” task was most affected by increased load magnitude as muscle activity attributed to load was significantly different (p<0.05) under increased loading conditions in both movement phases in all muscles. Further, a significant interactional effect (p<0.05) between condition and data point was found in all muscles with the exception of the right and left lumbar erector spinae during the second movement phase of the “hip reach” task. Muscle activity associated with increased trunk motion resulted in additional strain on the trunk muscles in the “hip shoulder” and “hip reach” tasks as muscle activity associated with the static component of each of the above tasks was greater than that of the dynamic tasks. Trend of ground reaction forces attributed to increased trunk motion generally increased under increased loading conditions. Additionally, a significant interactional effect (p<0.05) between load and muscle activity pattern was found in all muscles during all tasks, with the exception of the right rectus abdominis in the first movement phase of the “hip shoulder’ task, the left rectus abdominis in the second movement phase of the “hip knee” task and the right latissimus dorsi during the first movement phase of the “hip twist” task. This was accompanied by a significant interactional effect (p<0.05) between load and sagittal centre of pressure movement attributed to load, in both movement phases of all tasks investigated. From this research it can be proposed that guidelines may underestimate risk and subsequently under predict the strain in tasks performed with greater external loads as well as tasks which require a greater degree of trunk motion. Therefore, this study illustrates the importance of the consideration of the muscle activity necessary to maintain postural equilibrium in overall load analyses.
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  • Date Issued: 2010

Learners' perceptions of creating a collaborative hypermedia product: an exploratory case study at Mount Pleasant Primary School

  • Authors: du Plessis, André
  • Date: 2004
  • Subjects: Computer-assisted instruction -- South Africa Computers -- Study and teaching -- South Africa Education, Elementary -- Activity programs Competency-based education -- South Africa Educational technology -- South Africa
  • Language: English
  • Type: Thesis , Masters , MEd
  • Identifier: vital:1663 , http://hdl.handle.net/10962/d1003546
  • Description: The Ministry of Education (SICTE, 2002) states that the widespread introduction of computers in schools should support Curriculum 2005 and that computer technology is part and parcel of making schools the center of community life. The vision is to establish Smart Schools: schools that are reinvented in terms of teaching-learning practices to prepare learners for the information era (SICTE, 2002). Kafai (1996:71) has found that conventional school assignments rarely give learners the opportunity to spend a great deal of time on complex projects. As a result, many learners have little experience in design: planning, problem solving, researching, dealing with time constraints, modifying expectations and synthesizing everything in a project. Research by Carver, Lehrer, Connell and Erickson (1992); Lehrer, (1993); Lehrer, Erickson and Connell (1994); Kafai (1996); Liu and Hsiao (2002) and Liu (2002) indicates that the design of hypermedia artefacts can assist in providing experience in design. To date, no equivalent research has been conducted in South Africa to ascertain the perceptions of learners regarding the creation of a hypermedia artefact over an extended period of time and whether some of the critical outcomes specified in Curriculum 2005 can be addressed in such a learning-by-design hypermedia project. This study shows that design skills and aspects related to the critical outcomes of Curriculum 2005 can be achieved. Furthermore, it indicates that this kind of project encourages interest, motivation and collaboration. In addition, it suggests that learners experience the role of the teacher as different and prefer such a learning environment. In spite of the positive results, some aspects that need attention for future implementation are suggested.
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  • Date Issued: 2004

Regulation of tryptophan-2,3-dioxygenase and pineal indoleamines by selected tryptophan derivatives and antidepressants

  • Authors: Walsh, Harold Archibold
  • Date: 1997
  • Subjects: Antidepressants Tryptophan -- Physiological effect Tryptophan -- Therapeutic use Depression, Mental -- Treatment
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:4017 , http://hdl.handle.net/10962/d1004077
  • Description: The regulation of tryptophan-2,3-dioxygenase (TDO) (EC 1.13.1.12) and, to a lesser extent, pineal indoleamines, both in vitro and in vivo, is examined in this study. Rat liver TDO is a cytosolic enzyme which plays a crucial role in the regulation of circulating tryptophan (TRP) levels. Stimulation of this enzyme by heme enhances the catabolism of TRP, making less TRP available for uptake into the brain and other tissues, and for protein synthesis. At pH 7, the enzyme has an approximate Km of 100μM, is subject to substrate inhibition immediately beyond Sopt([S] at Vmax), and response of the enzyme is cooperative in both uninhibited and inhibited regions. Hill analysis of the uninhibited region reveals a biphasic plot and two classes of binding sites. Negative cooperativity is brought about through deprotonation of the enzyme. Substrate iphibition also occurs at both acidic and basic pH values with concomitant shifts in Sopt. The results obtained indicate that substrate inhibition could be an additional mechanism whereby the flux through the TRP-kynurenine pathway is regulated. TDO is subject to a diurnal rhythm, with peak activity during the pre-dark period and the loweSt activity towards the end of the dark period. It is possible that the enzyme controls the synthesis of the neurotransmitter serotonin (5-HT), and that the circadian rhythm in TDO activity is due to the endogenous rhythm of melatonin (aMT) production by the pineal gland. In the present study, aMT displaces TRP from bovine serum albumin (BSA) in vitro, and it is therefore possible for the indoleamine to regulate the availability of TRP for uptake into the brain for conversion to its derivatives. Chronic intraperitoneal administration of aMT affects physiological hepatic parameters in rats, such as TDO activity and stromal fatty acid composition, whilst no observable effect is demonstrable with respect to protein synthesis, nucleic acid metabolism, membrane fatty acid composition and pineal indole biosynthesis. On the other hand, chronic treatment of rats with antidepressants, the tricyclic desmethylimipramine (DMI) and the selective serotonin reuptake inhibitor (SSRI), fluoxetine, reveals significant negative alterations in TDO concentrations and pineal indole amine synthesis. Combining aMT with any of these two drugs normalises the activity of the hepatic enzyme. DMI is found to be an effective inhibitor of TDO in the micromolar range in vitro, and also affects total enzyme concentrations in vivo. Fluoxetine has no effect on TDO in vitro, but in vivo also reduces total enzyme levels in the liver. However, the SSRI does not affect conjugation between apo- and holoenzyme. Instead, it decreases extant holoenzyme levels. Indoleamine synthesis by the pineal gland, in organ culture, is altered by both antidepressants, although in different ways. DMI increases N-acetylserotonin levels and reduces the output of methoxyindole acetic acid and meth6xytryptophol. Fluoxetine treatment markedly reduces aMT concentrations and also brings about high levels of the 5-HT catabolites, 5-hydroxytryptophol and 5-hydroxyindole acetic acid. Insulin also lowers aMT synthesis significantly in pineal organ cultures, via a mechamsm that involves inhibition of the enzyme, N-acetyl transferase, that regulates aMT synthesis. The effects of insulin on pineal indole metabolism are due to the observation that a carbohydrate rich diet which induces insulin release elevates plasma TRP and brain 5-HT, but has no effect on pineal TRP and indole amine synthesis. It could thus be possible for insulin to have an effect on the pineal, since the latter is outside the blood brain barrier. The finilings of this study support the biogenic amine deficiency hypothesis, implicating some of the major biogenic amines such as noradrenaline (NA), 5-HT and aMT in depression. There is believed to be a deficiency of NA and 5-HT at their respective synapses in the depressed state. The drug DMI could act, firstly, by inhibiting TDO and thus increasing plasma TRP levels, and could, secondly, stimulate NA release and inhibit NA reuptake at the pineal membrane. The combined effect would be to enhance aMT synthesis, with eventual remission. Fluoxetine, on the other hand, appears to utilize a slightly different mode of action to DMI, which seems to focus on the preservation of 5-HT. The fact that aMT counteracts the effects of both antidepressants, and restores the activity of TDO to that of the controls, is also consistent with the observation that the therapeutic action of drugs such as these coincides willi the restoration of normal plasma levels of the neurohormone in depressives. In view of the biogenic amine deficiency hypothesis of depression and the contentious claim that TDO is the major peripheral determinant of brain TRP, brain 5-HT and ultimately aMT, the regulation of TDO is investigated and discussed. The study concludes that TDO activity is regulated by a number of endogenous compounds which are mainly derivatives of TRP, such as aMT and oxidized nicotinamide adenine dinucleotide and exogenous substances, of which DMI and fluoxetine are but two. In addition, modulation of IDO activity in depression appears to be an important aspect of antidepressant action. aMT, the product of the pineal gland, also has the potential to increase plasma TRP and hence forebrain TRP levels, and ultimately 5-HT concentrations, firstly by displacing TRP from serum albumin and secondly by inhibiting TDO.
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  • Date Issued: 1997

Biopharmaceutics of phenylpropanolamine

  • Authors: Dowse, Roslind
  • Date: 1984
  • Subjects: Biopharmaceutics Pharmacokinetics Phenylpropanolamine Pharmacology High performance liquid chromatography
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:3818 , http://hdl.handle.net/10962/d1004915
  • Description: Phenylpropanolamine (PPA), a sympathomimetic amine, has been widely used over the past 40 years as a decongestant and, in much larger dosages, as an appetite suppressant. Considerable interest has recently been shown in this drug due to its increasing popularity as an over-the-counter anorectic agent. Much controversy exists concerning the unfavourable side-effects of PPA resulting from the higher doses required for appetite suppression and the potential of this drug for abuse. A literature search revealed a paucity of information concerning the determination of PPA in biological fluids and, most noticeably, on the pharmacokinetics of this drug. An original method for determining PPA in serum and urine using high performance liquid chromatography (HPLC) which has increased sensitivity over other published HPLC methods is presented here. The simplicity of the extraction from biological fluids and subsequent determination by HPLC, enables concentrations of PPA to be monitored after a single dose of the drug. This method is therefore readily applicable to bioavailability and pharmacokinetic studies. The dissolution profiles of 4 sustained-release formulations of PPA were determined in a modified USP rotating paddle apparatus and the samples analysed using HPLC. A mathematical equation was applied to these data which are expressed in terms of dissolution parameters. Oral test dosage forms and solutions of PPA were investigated in bioavailability trials using the developed HPLC method to analyse the urine and serum samples. Linear one body compartment kinetics were assumed and the WagnerNelson method used to transform in vivo serum data to absorption plots which were then fitted to the well known Weibull equation. In order to more appropriately characterize the kinetic processes of absorption, distribution and elimination, a more complex model was utilized which involved numerical integration of a series of differential equations. The data were fitted to these models using nonlinear regression techniques. The pharmacokinetics of PPA are shown to exhibit some evidence of nonlinearity. The absorption of the drug appears to be di scontinuous and PPA seems to favour a two body compartment model.
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  • Date Issued: 1984

An econometrical estimation of the demand for money in South Africa : the long-run function during the period 1918-60

  • Authors: Maxwell, Thomas
  • Date: 1969
  • Subjects: Econometrics Keynesian economics Demand for money -- South Africa
  • Language: English
  • Type: Thesis , Doctoral , PhD
  • Identifier: vital:1065 , http://hdl.handle.net/10962/d1007618
  • Description: Introduction: In recent years there has been a marked upsurge in the output of literature dealing with the demand for money, but with the exception of the North American Continent, empirical research has lagged distressingly far behind the voluminous output of theory. This dearth of empirical results has had a restrictive influence. Since any of the controversial points which are being disputed by theoreticians can only be resolved by recourse to empirical methods. The restriction of empirical research to the North American Continent has further meant that the various points under dispute have had only a limited qualification and consequently monetary theorists have had no indication as to the universalizability of their conclusions. There is thus a great need for empirical studies in other countries so that the validity of the rival theories can be tested under different conditions. It was with these thoughts in mind that the present study was undertaken. Its objectives are strictly national and no pretense of strict international comparability is made. Further, great care has been taken to avoid the pitfall so beloved of econometricians, the fallacy of reduction wherein strictly limited results are uncritically universalized. Thus no attempt has been made to draw conclusions which will have universal validity. The theoretically vital points which are going to be examined in the light of South African experience are: 1. The feasibility of distinguishing idle from active balances, and if this proves possible, the determination of the wealth and interest elasticities of these balances; 2. Dropping the explicit distinction between idle and active balances to (a) determine the role of interest rates, (b) determine the appropriate constraint on the demand function, (c) determine what effect different definitions of money have on (a) and (b); 3. To examine the stability of the demand function over time. Truth is, of course, many-sided and any uniform presentation can only aspire to present a one-sided picture, just like a photograph cannot hope to do justice to the full grandeur of nature, merely presenting a one-dimensional representation of a many dimensioned object. In spite of this restriction which is inherent in all econometrical studies, this one-sided picture seems to be justified in view of the lack of any unified and coherent treatment of the demand for money in South Africa.
  • Full Text:
  • Date Issued: 1969
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