The effect of increased propolis production on the productivity of a honeybee farming system
- Authors: De Jager, Andries Johannes
- Date: 2001
- Subjects: Propolis
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10952 , http://hdl.handle.net/10948/d1001743 , Propolis
- Description: This study was conducted to investigate a method for stimulating increased propolis production in Cape honeybee hives. The study took place near George situated in the Southern Cape region of South Africa. Standard Langstroth hives were used (n = 12) containing honeybee colonies of equal strength from the species Apis mellifera capensis. Propolis production in colonies equipped with commercial propolis traps (n = 6) was compared to propolis production in control colonies (n = 6). The strength of the colonies was determined by calculating the area of worker brood cells and the number of frames containing bees. For a ninemonth period propolis production, honey production, brood area, resin percentage, frames containing bees and income generated were measured on a monthly basis with the removal of the traps. There were no significant difference (p > 0.5) in honey production (24.66 ± 1.19 kg and 26.53 ± 1.31 kg), worker brood area (1967.3 ± 258.61 cm2 and 1085.4 ± 312.99 cm2) and frames containing bees (10 ± 1.13 frames and 9.8 ± 1.2 frames) between the hives with traps and hives without traps. However, propolis production was significantly influenced (p < 0.01) by the propolis traps, with the hives containing traps producing 361.87 ± 8.78g propolis compared to 38.2 ± 2.17g propolis in the control group. Propolis production in both control (28 g) and treatment groups (260.2 g) was significantly influenced by honey flow (p = 0.027). From December to March the production of honey was 22.12 (control) and 24.25 kg (treatment). A positive correlation was also found between frames containing bees and worker brood area (R = 0.73). Hives containing propolis traps were more profitable than the control group when honey and propolis income were pooled (467.17 ± 19.47 Rand vs. 353.8 ± 17.03 Rand). Therefore, the increased propolis production significantly improved profitability of the hive without affecting overall hive productivity.
- Full Text:
- Date Issued: 2001
- Authors: De Jager, Andries Johannes
- Date: 2001
- Subjects: Propolis
- Language: English
- Type: Thesis , Masters , MTech (Agricultural Management)
- Identifier: vital:10952 , http://hdl.handle.net/10948/d1001743 , Propolis
- Description: This study was conducted to investigate a method for stimulating increased propolis production in Cape honeybee hives. The study took place near George situated in the Southern Cape region of South Africa. Standard Langstroth hives were used (n = 12) containing honeybee colonies of equal strength from the species Apis mellifera capensis. Propolis production in colonies equipped with commercial propolis traps (n = 6) was compared to propolis production in control colonies (n = 6). The strength of the colonies was determined by calculating the area of worker brood cells and the number of frames containing bees. For a ninemonth period propolis production, honey production, brood area, resin percentage, frames containing bees and income generated were measured on a monthly basis with the removal of the traps. There were no significant difference (p > 0.5) in honey production (24.66 ± 1.19 kg and 26.53 ± 1.31 kg), worker brood area (1967.3 ± 258.61 cm2 and 1085.4 ± 312.99 cm2) and frames containing bees (10 ± 1.13 frames and 9.8 ± 1.2 frames) between the hives with traps and hives without traps. However, propolis production was significantly influenced (p < 0.01) by the propolis traps, with the hives containing traps producing 361.87 ± 8.78g propolis compared to 38.2 ± 2.17g propolis in the control group. Propolis production in both control (28 g) and treatment groups (260.2 g) was significantly influenced by honey flow (p = 0.027). From December to March the production of honey was 22.12 (control) and 24.25 kg (treatment). A positive correlation was also found between frames containing bees and worker brood area (R = 0.73). Hives containing propolis traps were more profitable than the control group when honey and propolis income were pooled (467.17 ± 19.47 Rand vs. 353.8 ± 17.03 Rand). Therefore, the increased propolis production significantly improved profitability of the hive without affecting overall hive productivity.
- Full Text:
- Date Issued: 2001
The effect of photoperiod on some aspects of reproduction in a Southern African rodent : the pouched mouse (Saccostomus Campestris)
- Authors: Gray, Janine
- Date: 2001
- Subjects: Mice -- Reproduction Antechinus -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5676 , http://hdl.handle.net/10962/d1005361
- Description: The pouched mouse, Saccostomus campestris is widely distributed south of the Sahara, inhabiting both subtropical and tropical latitudes and a number of different biotic zones, where it breeds seasonally. In North temperate latitudes, reproduction in small mammals is controlled by photoperiod however this cue becomes less influential as latitude decreases towards the equator. The aim of the present study is to establish the role of photoperiod in the environmental control of reproduction in a seasonally breeding small mammal at low latitudes in a highly unpredictable environment. Spermatogenesis of domesticated and Fl-generation pouched mice was not inhibited by short daylength while decreasing daylength significantly affected the oestrous cycle of adult domesticated female pouched mice. Photoperiod had little effect on the oestrous cycle of F I-generation females while a possible inherent circannual endogenous rhythm controlled inhibition of reproduction in these females. Body mass of male and female juvenile pouched mice was consistently lower in short daylength and in juvenile female pouched mice the onset of fertility may be weight-dependent. The attainment of sexual maturity of domesticated and FIlF2-generation females was retarded but not halted in short daylength and females in long daylength reached puberty 7.8 - 10.2 days earlier. Short daylength also lengthened the interval between vaginal perforation and first oestrus. Puberty in juvenile females was age-dependent as both domesticated and FIlF2-generation males attained puberty at 50 days of age, although fewer males were fertile in long daylength than short daylength. Although litter size of pouched mice was smaller in short daylength for both domesticated and wildcaught females this was not due to a reduction in the ovulation rate. Domesticated females had significantly larger litters than wild-caught females. Male and female pouched mice have evolved different reproductive strategies as males become sexually mature at the same age irrespective of photoperiod and remain fertile throughout the year. In contrast, females tend to be more complex as juveniles delay reproductive maturity and adults become nonreproductive in short daylength. However, in the presence of a fertile male and if environmental conditions are favourable, in short daylength, females can become reproductively active within approximately 3 days. Thus, although the pouched mouse has adopted a purely opportunistic reproductive strategy, vestiges of photoresponsiveness are still present in the female. The seasonality exhibited in the wild is therefore due to the female. Pouched mice live in a highly unpredictable environment so the sole use of photoperiod to regulate reproduction would be disadvantageous.
- Full Text:
- Date Issued: 2001
- Authors: Gray, Janine
- Date: 2001
- Subjects: Mice -- Reproduction Antechinus -- Africa, Southern
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5676 , http://hdl.handle.net/10962/d1005361
- Description: The pouched mouse, Saccostomus campestris is widely distributed south of the Sahara, inhabiting both subtropical and tropical latitudes and a number of different biotic zones, where it breeds seasonally. In North temperate latitudes, reproduction in small mammals is controlled by photoperiod however this cue becomes less influential as latitude decreases towards the equator. The aim of the present study is to establish the role of photoperiod in the environmental control of reproduction in a seasonally breeding small mammal at low latitudes in a highly unpredictable environment. Spermatogenesis of domesticated and Fl-generation pouched mice was not inhibited by short daylength while decreasing daylength significantly affected the oestrous cycle of adult domesticated female pouched mice. Photoperiod had little effect on the oestrous cycle of F I-generation females while a possible inherent circannual endogenous rhythm controlled inhibition of reproduction in these females. Body mass of male and female juvenile pouched mice was consistently lower in short daylength and in juvenile female pouched mice the onset of fertility may be weight-dependent. The attainment of sexual maturity of domesticated and FIlF2-generation females was retarded but not halted in short daylength and females in long daylength reached puberty 7.8 - 10.2 days earlier. Short daylength also lengthened the interval between vaginal perforation and first oestrus. Puberty in juvenile females was age-dependent as both domesticated and FIlF2-generation males attained puberty at 50 days of age, although fewer males were fertile in long daylength than short daylength. Although litter size of pouched mice was smaller in short daylength for both domesticated and wildcaught females this was not due to a reduction in the ovulation rate. Domesticated females had significantly larger litters than wild-caught females. Male and female pouched mice have evolved different reproductive strategies as males become sexually mature at the same age irrespective of photoperiod and remain fertile throughout the year. In contrast, females tend to be more complex as juveniles delay reproductive maturity and adults become nonreproductive in short daylength. However, in the presence of a fertile male and if environmental conditions are favourable, in short daylength, females can become reproductively active within approximately 3 days. Thus, although the pouched mouse has adopted a purely opportunistic reproductive strategy, vestiges of photoresponsiveness are still present in the female. The seasonality exhibited in the wild is therefore due to the female. Pouched mice live in a highly unpredictable environment so the sole use of photoperiod to regulate reproduction would be disadvantageous.
- Full Text:
- Date Issued: 2001
The effect of variations in pH and temperature on stability of melatonin in aqueous solution
- Daya, Santylal, Walker, Roderick B, Glass, Beverley D, Anoopkumar-Dukie, Shailendra
- Authors: Daya, Santylal , Walker, Roderick B , Glass, Beverley D , Anoopkumar-Dukie, Shailendra
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184314 , vital:44207 , xlink:href="https://doi.org/10.1034/j.1600-079x.2001.310209.x"
- Description: Melatonin (N-acetyl-5-methoxytryptamine) has a diverse range of functions, including the control of neuroendocrine events. A number of studies have shown that melatonin may be of potential benefit for the treatment of insomnia, as well as neurodegenerative disorders. At present, there are numerous dosage forms of melatonin, with the oral route of administration being most popular. Presently, there is little information on the stability of melatonin over a pH range. With the changes in pH in the gastro-intestinal tract, as well as in different experimental conditions, information on the stability of melatonin would be important. We used a high-performance liquid chromatography method to determine the stability of melatonin solutions over a pH range (1.2–12) at room temperature and at 37°C over a period of 21 days. The results show that no melatonin degradation occurred in the first 2 days. From days 3 to 21, there was a gradual decline in melatonin at all pHs, with the decline not exceeding 30%. No decline in melatonin levels occurred in the first 2 days at 37°C. From days 3 to 21, melatonin levels declined gradually, with the decline not exceeding 29%.
- Full Text:
- Date Issued: 2001
- Authors: Daya, Santylal , Walker, Roderick B , Glass, Beverley D , Anoopkumar-Dukie, Shailendra
- Date: 2001
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184314 , vital:44207 , xlink:href="https://doi.org/10.1034/j.1600-079x.2001.310209.x"
- Description: Melatonin (N-acetyl-5-methoxytryptamine) has a diverse range of functions, including the control of neuroendocrine events. A number of studies have shown that melatonin may be of potential benefit for the treatment of insomnia, as well as neurodegenerative disorders. At present, there are numerous dosage forms of melatonin, with the oral route of administration being most popular. Presently, there is little information on the stability of melatonin over a pH range. With the changes in pH in the gastro-intestinal tract, as well as in different experimental conditions, information on the stability of melatonin would be important. We used a high-performance liquid chromatography method to determine the stability of melatonin solutions over a pH range (1.2–12) at room temperature and at 37°C over a period of 21 days. The results show that no melatonin degradation occurred in the first 2 days. From days 3 to 21, there was a gradual decline in melatonin at all pHs, with the decline not exceeding 30%. No decline in melatonin levels occurred in the first 2 days at 37°C. From days 3 to 21, melatonin levels declined gradually, with the decline not exceeding 29%.
- Full Text:
- Date Issued: 2001
The effects of assembly line-side supply on individuals employed in satellite operations within automotive manufacturers
- Authors: Bocchi, Carlo
- Date: 2001
- Subjects: Faurecia East London (Firm) , Job satisfaction , Employee motivation , Automobile industry and trade -- Management , Automobile industry and trade -- Case studies
- Language: English
- Type: Thesis , Masters , MTech (Business Administration)
- Identifier: vital:10849 , http://hdl.handle.net/10948/56 , Faurecia East London (Firm) , Job satisfaction , Employee motivation , Automobile industry and trade -- Management , Automobile industry and trade -- Case studies
- Description: The adoption of just-in-time in satellite operations within an automotive manufacturer, is rapidly becoming a trend within motor industry clusters. This type of organisation within an organisation adopts a lean structure to operate effectively and efficiently. The objective of this paper is to unveil factors which influence this type of workplace, particularly focusing on which factors which are relevant to Faurecia East London Plant. The literature study was used to illustrate the various theories relevant to manufacturing techniques, employee motivational and job satisfaction theories. The empirical study tested factors illustrated in the literature study. The empirical study was also to develop a specific model suitable for satellite organisations. The model presented together with the literature and empirical study was used to formulate findings and solve the main and sub-problems.
- Full Text:
- Date Issued: 2001
- Authors: Bocchi, Carlo
- Date: 2001
- Subjects: Faurecia East London (Firm) , Job satisfaction , Employee motivation , Automobile industry and trade -- Management , Automobile industry and trade -- Case studies
- Language: English
- Type: Thesis , Masters , MTech (Business Administration)
- Identifier: vital:10849 , http://hdl.handle.net/10948/56 , Faurecia East London (Firm) , Job satisfaction , Employee motivation , Automobile industry and trade -- Management , Automobile industry and trade -- Case studies
- Description: The adoption of just-in-time in satellite operations within an automotive manufacturer, is rapidly becoming a trend within motor industry clusters. This type of organisation within an organisation adopts a lean structure to operate effectively and efficiently. The objective of this paper is to unveil factors which influence this type of workplace, particularly focusing on which factors which are relevant to Faurecia East London Plant. The literature study was used to illustrate the various theories relevant to manufacturing techniques, employee motivational and job satisfaction theories. The empirical study tested factors illustrated in the literature study. The empirical study was also to develop a specific model suitable for satellite organisations. The model presented together with the literature and empirical study was used to formulate findings and solve the main and sub-problems.
- Full Text:
- Date Issued: 2001
The effects of level and quality of education on a South African sample of English and African first language speakers, for WAIS-III digit symbol-incidental learning
- Donnelly, Martin Joseph Rhodes
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
- Full Text:
- Date Issued: 2001
- Authors: Donnelly, Martin Joseph Rhodes
- Date: 2001
- Subjects: Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2965 , http://hdl.handle.net/10962/d1002474 , Wechsler Adult Intelligence Scale , Intelligence tests -- South Africa , Wechsler Adult Intelligence Scale -- South Africa
- Description: This study examined the effects of level and quality of education on WAIS-III Digit Symbol-Incidental Learning performance. The Pairing and Free Recall measures were administered to a South African sample (N = 68, age range 19-30), which was stratified for English and African language, level of education attained (Grade 12s and Graduates) and quality of education (advantaged and disadvantaged schooling). Results yielded no significant main or interaction effects between acculturation factors of level and quality of education. Normative guidelines of 13 or more pairs and 8 or more free recall symbols, appropriate to a non-clinical sample in a multicultural setting, are provided. Digit Symbol-Incidental Learning proved to be a culture-fair test, which contributes to its clinical utility as a sensitive memory screening tool.
- Full Text:
- Date Issued: 2001
The effects of melatonin on the testis, epididymis and sperm physiology of the Wistar rat
- Authors: Gwayi, Noluzuko
- Date: 2001
- Subjects: Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5681 , http://hdl.handle.net/10962/d1005366 , Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Description: Melatonin is a product of the pineal gland and is postulated to play an antigonadotropic role in the reproductive system of mammals. The reproductive system of non-seasonally breeding mammals is believed to be not as responsive to melatonin treatment as that of seasonally breeding mammals. Recently, there has been increasing support from in vivo and in vitro studies, for the hypothesis that melatonin has negative effects on sperm physiology, especially on sperm motility. High and/or low seminal concentrations of melatonin have been associated with abnormalities in human sperm motility and concentration. In this study, I examined the effects of melatonin on the testis, epididymis and sperm physiology, using in vivo and in vitro experiments, in a non-seasonally breeding mammal. Treatment, in vivo, with exogenous melatonin for six weeks did not inhibit testosterone production or spermatogenesis, nor did it affect the mass of the testes and epididymides at dissection, the concentration the morphology of speimatozoa. However, melatonin in vivo had a small, but significant negative effect on sperm motility and sperm motility index. In vitro incubation of spermatozoa Fith melatonin reduced the percentage (%) of forward progressive movement (fpm), increased the % reduction in fpm, reduced the vigor or quality of sperm motility, reduced the sperm motility index, and delayed and/or prolonged the transition of one pattern of sperm motility to the subsequent patterns. Melatonin increased the pH of the culture medium, and the increased pH, and the ethanol utilized as a solvent for melatonin, both negatively affected all the sperm motility parameters that were assessed in my study. The effects of ethanol increased with time, and the effects of pH increased with both time and increasing pH. Melatonin in vitro did not inhibit capacitation and the acrosome reaction, but it delayed the onset and the progression of capacitation and the acrosome reaction. These results suggest that while melatonin did not inhibit spermatogenesis in the Wistar rat, it may influence sperm motility. Therefore, the presence of high concentrations of melatonin in the reproductive fluids may inhibit sperm motility. With further detailed research, melatonin may have a potential use as a contraceptive drug.
- Full Text:
- Date Issued: 2001
- Authors: Gwayi, Noluzuko
- Date: 2001
- Subjects: Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5681 , http://hdl.handle.net/10962/d1005366 , Rats as laboratory animals , Rats -- physiology , Spermatozoa , Melatonin , Testis , Epididymis
- Description: Melatonin is a product of the pineal gland and is postulated to play an antigonadotropic role in the reproductive system of mammals. The reproductive system of non-seasonally breeding mammals is believed to be not as responsive to melatonin treatment as that of seasonally breeding mammals. Recently, there has been increasing support from in vivo and in vitro studies, for the hypothesis that melatonin has negative effects on sperm physiology, especially on sperm motility. High and/or low seminal concentrations of melatonin have been associated with abnormalities in human sperm motility and concentration. In this study, I examined the effects of melatonin on the testis, epididymis and sperm physiology, using in vivo and in vitro experiments, in a non-seasonally breeding mammal. Treatment, in vivo, with exogenous melatonin for six weeks did not inhibit testosterone production or spermatogenesis, nor did it affect the mass of the testes and epididymides at dissection, the concentration the morphology of speimatozoa. However, melatonin in vivo had a small, but significant negative effect on sperm motility and sperm motility index. In vitro incubation of spermatozoa Fith melatonin reduced the percentage (%) of forward progressive movement (fpm), increased the % reduction in fpm, reduced the vigor or quality of sperm motility, reduced the sperm motility index, and delayed and/or prolonged the transition of one pattern of sperm motility to the subsequent patterns. Melatonin increased the pH of the culture medium, and the increased pH, and the ethanol utilized as a solvent for melatonin, both negatively affected all the sperm motility parameters that were assessed in my study. The effects of ethanol increased with time, and the effects of pH increased with both time and increasing pH. Melatonin in vitro did not inhibit capacitation and the acrosome reaction, but it delayed the onset and the progression of capacitation and the acrosome reaction. These results suggest that while melatonin did not inhibit spermatogenesis in the Wistar rat, it may influence sperm motility. Therefore, the presence of high concentrations of melatonin in the reproductive fluids may inhibit sperm motility. With further detailed research, melatonin may have a potential use as a contraceptive drug.
- Full Text:
- Date Issued: 2001
The evaluation of autoxidation procedures for the selective oxidation of aliphatic alcohols
- Authors: Bacela, Siyabulela Mawande
- Date: 2001
- Subjects: Oxidation , Aliphatic compounds
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10950 , http://hdl.handle.net/10948/59 , Oxidation , Aliphatic compounds
- Description: The homogeneously catalyzed oxidation of 1-propanol by dioxygen in glacial acetic acid using cobalt(II)acetate and sodium bromide as the catalyst system has been investigated with the view of determining the significance of various experimental variables during the oxidation. The results of this investigation show unequivocally that a number of reaction variables have a direct influence upon catalytic activity and hence the reaction products. It is quite evident that the major product of this autoxidation reaction is propionic acid with the respective esters as side-products. This is an indication that the autoxidation mechanism occurs via a two-stage pathway, namely, the oxidation of 1-propanol to propionaldehyde as the primary product and, subsequently, the further oxidation of the propionaldehyde to propionic acid as the major product. Thus the esterification process of the propionic acid with the substrate 1-propanol could be termed as a side-reaction because its not facilitated by the catalyst system and it consumes the formed product. The catalyst activity has been demonstrated to depend on a number of factors, including the bromide concentration, the cobalt(II)acetate concentration, the water concentration, reaction temperature, and the presence of metal acetates as co-catalysts. There is an observed decrease in catalytic activity at high bromide concentration, which may be explained in terms of cobalt bromide complexes that form at these high concentrations. Subsequently, the same trend of catalyst activity reduction at high cobalt(II)acetate concentration may be ascribed to the “inactive” metal complexes that are susceptible to form at high metal ion concentrations. The catalytic activity increases with increase in total concentration and rapidly decreases at very high concentrations. This can be explained in terms of the observations made during the investigation of the effect of cobalt(II)acetate and bromide concentrations. The high increase in catalytic activity with increasing temperature is ascribed to the Arrhenius law, which relates the rate constant for a particular reaction to temperature. However, there is an observed loss of catalyst selectivity at high temperatures which maybe due to two possible factors. The first is simply related to an increased loss of volatile material from the reactor in the oxygen gas stream as the temperature is increased. The second relates to the increasing activity of the catalyst system for the selective decarboxylation of the carboxylic acid product. The addition of water to the reaction system rapidly reduces the catalyst activity. This detrimental effect is an indication that there is an effective competition by water with bromide for coordination sites on cobalt(II), thereby preventing the formation of the active catalyst species. The introduction of metal acetates as co-catalyst reduces the catalyst activity quite dramatically. This inhibition effect is suggested to relate to the redox potential of the respective metal ions. The results of statistical analysis of the experimentally derived response surface during the oxidation of 1-propanol, show no significant lack of fit, and the residuals obtained by applying the response surface to the design settings show that the data is normally distributed. The response surface is therefore reliable, but keeping in mind that the central composite design used is not rotatable so that its predictive power, especially outside the experimental domain investigated, is quite limited. However, several interesting observations were still possible The oxidative dehydrogenation of ethanol over supported noble-metal catalysts has been investigated with the view of identifying the most active supported noble-metal and also to compare this oxidation procedure with the autoxidation procedure. Secondly, the effect of an acidic resin as a co-catalyst was also investigated during the said oxidation. On the basis of results presented in this study during oxidative dehydrogenation of ethanol, catalysts no.2 (10% Pd/C), 8 (2% Pd/Al – Pb-promoted) and 9 (2% Pt/8% Pd/C) appear to be the most active in terms of relative rates, while catalysts 6 (10% Pd/C- Pbpromoted), 7 (5% Pd/C-shell reduced-Pb -promoted) and 10 (5% Pt 5% Pd on C) are more active based on the comparison of average rates. Two other observations are of interest. Firstly, the promotion of the Pd catalysts with lead appears to improve catalyst activity to some extent as shown by the comparisons between catalysts 1 and 5, 4 and 8, 2 and 6 and 3 and 7. Secondly, the introduction of Pt up to equal amounts with palladium seems to produce the most active catalysts. On its own, platinum appears to be a better catalyst than Pd when supported on activated carbon (catalysts 1 and 12). In comparison with the homogeneous, cobalt-bromide catalyzed oxidation of 1- propanol in the liquid-phase, oxidations over noble-metal catalysts in the liquid-phase appear to be significantly less active. The presence of the resin promoted the formation of ethyl acetate to some extent, the improvements are not as dramatic as expected.
- Full Text:
- Date Issued: 2001
- Authors: Bacela, Siyabulela Mawande
- Date: 2001
- Subjects: Oxidation , Aliphatic compounds
- Language: English
- Type: Thesis , Masters , MTech (Chemistry)
- Identifier: vital:10950 , http://hdl.handle.net/10948/59 , Oxidation , Aliphatic compounds
- Description: The homogeneously catalyzed oxidation of 1-propanol by dioxygen in glacial acetic acid using cobalt(II)acetate and sodium bromide as the catalyst system has been investigated with the view of determining the significance of various experimental variables during the oxidation. The results of this investigation show unequivocally that a number of reaction variables have a direct influence upon catalytic activity and hence the reaction products. It is quite evident that the major product of this autoxidation reaction is propionic acid with the respective esters as side-products. This is an indication that the autoxidation mechanism occurs via a two-stage pathway, namely, the oxidation of 1-propanol to propionaldehyde as the primary product and, subsequently, the further oxidation of the propionaldehyde to propionic acid as the major product. Thus the esterification process of the propionic acid with the substrate 1-propanol could be termed as a side-reaction because its not facilitated by the catalyst system and it consumes the formed product. The catalyst activity has been demonstrated to depend on a number of factors, including the bromide concentration, the cobalt(II)acetate concentration, the water concentration, reaction temperature, and the presence of metal acetates as co-catalysts. There is an observed decrease in catalytic activity at high bromide concentration, which may be explained in terms of cobalt bromide complexes that form at these high concentrations. Subsequently, the same trend of catalyst activity reduction at high cobalt(II)acetate concentration may be ascribed to the “inactive” metal complexes that are susceptible to form at high metal ion concentrations. The catalytic activity increases with increase in total concentration and rapidly decreases at very high concentrations. This can be explained in terms of the observations made during the investigation of the effect of cobalt(II)acetate and bromide concentrations. The high increase in catalytic activity with increasing temperature is ascribed to the Arrhenius law, which relates the rate constant for a particular reaction to temperature. However, there is an observed loss of catalyst selectivity at high temperatures which maybe due to two possible factors. The first is simply related to an increased loss of volatile material from the reactor in the oxygen gas stream as the temperature is increased. The second relates to the increasing activity of the catalyst system for the selective decarboxylation of the carboxylic acid product. The addition of water to the reaction system rapidly reduces the catalyst activity. This detrimental effect is an indication that there is an effective competition by water with bromide for coordination sites on cobalt(II), thereby preventing the formation of the active catalyst species. The introduction of metal acetates as co-catalyst reduces the catalyst activity quite dramatically. This inhibition effect is suggested to relate to the redox potential of the respective metal ions. The results of statistical analysis of the experimentally derived response surface during the oxidation of 1-propanol, show no significant lack of fit, and the residuals obtained by applying the response surface to the design settings show that the data is normally distributed. The response surface is therefore reliable, but keeping in mind that the central composite design used is not rotatable so that its predictive power, especially outside the experimental domain investigated, is quite limited. However, several interesting observations were still possible The oxidative dehydrogenation of ethanol over supported noble-metal catalysts has been investigated with the view of identifying the most active supported noble-metal and also to compare this oxidation procedure with the autoxidation procedure. Secondly, the effect of an acidic resin as a co-catalyst was also investigated during the said oxidation. On the basis of results presented in this study during oxidative dehydrogenation of ethanol, catalysts no.2 (10% Pd/C), 8 (2% Pd/Al – Pb-promoted) and 9 (2% Pt/8% Pd/C) appear to be the most active in terms of relative rates, while catalysts 6 (10% Pd/C- Pbpromoted), 7 (5% Pd/C-shell reduced-Pb -promoted) and 10 (5% Pt 5% Pd on C) are more active based on the comparison of average rates. Two other observations are of interest. Firstly, the promotion of the Pd catalysts with lead appears to improve catalyst activity to some extent as shown by the comparisons between catalysts 1 and 5, 4 and 8, 2 and 6 and 3 and 7. Secondly, the introduction of Pt up to equal amounts with palladium seems to produce the most active catalysts. On its own, platinum appears to be a better catalyst than Pd when supported on activated carbon (catalysts 1 and 12). In comparison with the homogeneous, cobalt-bromide catalyzed oxidation of 1- propanol in the liquid-phase, oxidations over noble-metal catalysts in the liquid-phase appear to be significantly less active. The presence of the resin promoted the formation of ethyl acetate to some extent, the improvements are not as dramatic as expected.
- Full Text:
- Date Issued: 2001
The evaluation of pharmaceutical pictograms in a low-literate South African population
- Dowse, Roslind, Ehlers, Martina S
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6362 , http://hdl.handle.net/10962/d1006058
- Description: An inability to read and understand written medication instructions may be a major contributory factor to non-compliance in certain patient populations, particularly in countries with a high illiteracy rate such as South Africa. Twenty three pictograms from the USP-DI and a corresponding set of 23 locally developed, culturally sensitive pictograms for conveying medication instructions were evaluated in 46 Xhosa respondents who had attended school for a maximum of 7 years. Respondents were tested for their interpretation of all 46 pictograms at the first interview and again 3 weeks later. The correct meaning of each pictogram was explained at the end of the first interview. Preference for either the Local or USP pictograms was determined. At the follow-up interview, 20 of the Local pictograms complied with the ANSI criterion of ≥85% comprehension, compared with 11 of the USP pictograms. Respondents indicated an overwhelming preference for the Local pictograms.
- Full Text:
- Date Issued: 2001
- Authors: Dowse, Roslind , Ehlers, Martina S
- Date: 2001
- Language: English
- Type: Article
- Identifier: vital:6362 , http://hdl.handle.net/10962/d1006058
- Description: An inability to read and understand written medication instructions may be a major contributory factor to non-compliance in certain patient populations, particularly in countries with a high illiteracy rate such as South Africa. Twenty three pictograms from the USP-DI and a corresponding set of 23 locally developed, culturally sensitive pictograms for conveying medication instructions were evaluated in 46 Xhosa respondents who had attended school for a maximum of 7 years. Respondents were tested for their interpretation of all 46 pictograms at the first interview and again 3 weeks later. The correct meaning of each pictogram was explained at the end of the first interview. Preference for either the Local or USP pictograms was determined. At the follow-up interview, 20 of the Local pictograms complied with the ANSI criterion of ≥85% comprehension, compared with 11 of the USP pictograms. Respondents indicated an overwhelming preference for the Local pictograms.
- Full Text:
- Date Issued: 2001
The experiences of couples in relationships characterized by alcohol dependency
- Authors: Mgilane, Nomgcobo Eunice
- Date: 2001
- Subjects: Alcoholism -- South Africa Alcoholics -- Family relationships Alcoholics' spouses -- South Africa Alcoholics -- South Africa -- Conduct of life
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:702 , http://hdl.handle.net/10962/d1006461
- Description: The study focused on the expenences of Xhosa-speaking couples in relationships characterized by alcohol dependency. The goal was to generate greater understanding of the descriptions of relationship issues faced by alcohol dependent respondents and their partners. Specifically, the study focused on exploring how the alcohol dependent respondents relate to their partners, their behaviour at home when drinking prior to their admission for rehabilitation, the experiences of their partners in living with alcohol dependent partners and how they coped with the situation. In order to meet this goal, literature and empirical studies were conducted. The literature study focuses on the alcohol dependent individual's behaviour, his emotions, relapse, the family's coping strategies, alcohol and marital problems and the role of the social worker as part of the rehabilitation team. During the empirical research phase, a non-probability purposive sampling procedure was adopted. Fifteen alcohol dependent clients who were admitted for treatment and rehabilitation at Thembelitsha Rehabilitation Centre (TRC) were selected. These clients were admitted to TRC during the period starting from January 1997 to June 1999 and were discharged to their homes during the research study. To collect data, interviews were conducted separately to a total of thirty respondents. Two interview schedules were used, one for the alcohol dependent respondents (Appendix A) and the other for their partners (Appendix B). This study revealed a remarkable consistency in the descriptions of relationship issues faced by alcohol dependent respondents and their partners. These are abusive behaviours by alcohol dependent respondents. The partners were reluctant and feared challenging the behaviour. The way in which partners responded to drinking and the reactions of alcohol dependent respondents are indicative of the difficult issues faced by the couples. The study also revealed that couples experience communication, financial and sexual relationship problems. The study concludes with recommendations based on the research findings
- Full Text:
- Date Issued: 2001
- Authors: Mgilane, Nomgcobo Eunice
- Date: 2001
- Subjects: Alcoholism -- South Africa Alcoholics -- Family relationships Alcoholics' spouses -- South Africa Alcoholics -- South Africa -- Conduct of life
- Language: English
- Type: Thesis , Masters , MSocSc
- Identifier: vital:702 , http://hdl.handle.net/10962/d1006461
- Description: The study focused on the expenences of Xhosa-speaking couples in relationships characterized by alcohol dependency. The goal was to generate greater understanding of the descriptions of relationship issues faced by alcohol dependent respondents and their partners. Specifically, the study focused on exploring how the alcohol dependent respondents relate to their partners, their behaviour at home when drinking prior to their admission for rehabilitation, the experiences of their partners in living with alcohol dependent partners and how they coped with the situation. In order to meet this goal, literature and empirical studies were conducted. The literature study focuses on the alcohol dependent individual's behaviour, his emotions, relapse, the family's coping strategies, alcohol and marital problems and the role of the social worker as part of the rehabilitation team. During the empirical research phase, a non-probability purposive sampling procedure was adopted. Fifteen alcohol dependent clients who were admitted for treatment and rehabilitation at Thembelitsha Rehabilitation Centre (TRC) were selected. These clients were admitted to TRC during the period starting from January 1997 to June 1999 and were discharged to their homes during the research study. To collect data, interviews were conducted separately to a total of thirty respondents. Two interview schedules were used, one for the alcohol dependent respondents (Appendix A) and the other for their partners (Appendix B). This study revealed a remarkable consistency in the descriptions of relationship issues faced by alcohol dependent respondents and their partners. These are abusive behaviours by alcohol dependent respondents. The partners were reluctant and feared challenging the behaviour. The way in which partners responded to drinking and the reactions of alcohol dependent respondents are indicative of the difficult issues faced by the couples. The study also revealed that couples experience communication, financial and sexual relationship problems. The study concludes with recommendations based on the research findings
- Full Text:
- Date Issued: 2001
The garden as a metaphor for paradise
- Authors: Adlard, Michelle Catherine
- Date: 2001
- Subjects: Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2391 , http://hdl.handle.net/10962/d1002187 , Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Description: In this half thesis the use of the garden as a metaphor for paradise has been explored. The English word “ paradise“ was derived from the Greek word “ paradeisos” which in turn was derived from the Old Avestana “ pairi-daeza,” meaning an enclosure. In Ancient Persia the concept applied to an enclosed garden in the modern sense of the word. For this reason the thesis begins with an examination of the development of the garden in this desert region. A more-or-less continuous chain of development in both the physical and allegorical nature of the garden is traced through history from these Ancient Persian beginnings to the height of Mughal architecture (epitomised by the Taj Mahal), by way of the Muslim expansion through Central Asia and Europe. While the core elements of garden design were set in Ancient Persian times, and recur throughout the period studied, the impact of Islam on the local Persian culture brought about a new development of allegorical meaning associated with the garden. This allegorical development reached its apex, too, in the Taj Mahal in which, it is argued, the metaphorical representation of paradise in the garden tomb was made astonishingly explicit. The research for this mini thesis was gathered from secondary sources, including many published books and academic papers, photographic and diagrammatic evidence of extant ancient gardens, and reproductions of carpet designs.
- Full Text:
- Date Issued: 2001
- Authors: Adlard, Michelle Catherine
- Date: 2001
- Subjects: Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2391 , http://hdl.handle.net/10962/d1002187 , Paradise in art , Garden of paradise , Gardens -- Design -- Early works to 1800
- Description: In this half thesis the use of the garden as a metaphor for paradise has been explored. The English word “ paradise“ was derived from the Greek word “ paradeisos” which in turn was derived from the Old Avestana “ pairi-daeza,” meaning an enclosure. In Ancient Persia the concept applied to an enclosed garden in the modern sense of the word. For this reason the thesis begins with an examination of the development of the garden in this desert region. A more-or-less continuous chain of development in both the physical and allegorical nature of the garden is traced through history from these Ancient Persian beginnings to the height of Mughal architecture (epitomised by the Taj Mahal), by way of the Muslim expansion through Central Asia and Europe. While the core elements of garden design were set in Ancient Persian times, and recur throughout the period studied, the impact of Islam on the local Persian culture brought about a new development of allegorical meaning associated with the garden. This allegorical development reached its apex, too, in the Taj Mahal in which, it is argued, the metaphorical representation of paradise in the garden tomb was made astonishingly explicit. The research for this mini thesis was gathered from secondary sources, including many published books and academic papers, photographic and diagrammatic evidence of extant ancient gardens, and reproductions of carpet designs.
- Full Text:
- Date Issued: 2001
The gift of music
- Authors: Thomas, Cornelius
- Date: 2001
- Subjects: Maqhula, Abe Dludlu, Jimmy Guitarists -- South Africa Jazz musicians -- South Africa
- Type: article
- Identifier: http://hdl.handle.net/10962/32826 , vital:24085 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , MS 20 019
- Description: Photocopied article from the newspaper The Daily Dispatch about handing over of a guitar which was bought buy Jimmy Dludlu as a gift to Abe "Kruger" Maqhula
- Full Text:
- Date Issued: 2001
- Authors: Thomas, Cornelius
- Date: 2001
- Subjects: Maqhula, Abe Dludlu, Jimmy Guitarists -- South Africa Jazz musicians -- South Africa
- Type: article
- Identifier: http://hdl.handle.net/10962/32826 , vital:24085 , This image is held at the Cory Library for Humanities Research at Rhodes University. For further information contact cory@ru.ac.za. The digitisation of this image was made possible through a generous grant received from the Andrew W. Mellon Foundation 2014-2017. , MS 20 019
- Description: Photocopied article from the newspaper The Daily Dispatch about handing over of a guitar which was bought buy Jimmy Dludlu as a gift to Abe "Kruger" Maqhula
- Full Text:
- Date Issued: 2001
The goddess, the witch and the bitch : three studies in the perception of women
- Authors: Hare, Nicola Tracy
- Date: 2001
- Subjects: Feminism in literature , Women's rights in literature , Feminism and literature , Patriarchy in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10986 , http://hdl.handle.net/10948/278 , Feminism in literature , Women's rights in literature , Feminism and literature , Patriarchy in literature
- Description: In the minds of many people all over the world, women are ‘second class citizens’, standing accused of the downfall of mankind ever since Eve allegedly ate the apple. Even amongst those who do not openly denigrate women, there are many who do so in other, more subtle ways even if they are unaware of it. This study proposes to challenge such a view of women by exposing the ways in which perceptions of women are constructed by society, which frequently wants to maintain the status quo of male dominance. This study employs a feminist approach in examining this gynocentric theme, along with cultural studies which, with its focus on power relations and ways of decentring power structures, is also clearly of use. In addition, this multidisciplinary approach of cultural studies offers the possibility of studying literary texts as well as popular culture. Three specific time periods are examined, with a view to uncovering negative perceptions of women and ways that women can resist such attempts to control them. In chapter one, the focus turns to contemporary perceptions of prehistoric women and the ways that so-called ‘objective’ science has failed to represent women accurately. Similarly, ‘objective’ accounts of Goddess-worship – which frequently fail to examine this phenomenon adequately – are revisited. Alice Walker’s The Temple of My Familiar (1989) is discussed as a text which acts as a site of resistance to societally-informed perceptions. Chapter two continues this investigation by turning to the concept of the witch and its maligned association with women. Woman and witchcraft, having been associated for centuries, are investigated as a pairing which frequently results because iii of attempts to control women by androcentric society. In such situations, the practising of witchcraft can actually become a form of resistance to patriarchy. The pernicious effect of society’s need to purge itself – by witch hunts – of witches is also investigated. The Devil’s Chimney (1997) by Anne Landsman and “The prophetess” (1994) by Njabulo S. Ndebele are discussed as texts which examine fictionalised South African versions of this phenomenon. Sinead O’Connor, the Irish singer, is the ‘bitch’ discussed in chapter three. She is examined as a woman who offers strong and on-going resistance to patriarchal ways of thinking which would ‘box’ women in. This singer refuses to accept societal roles which are offered to women and so offers means of resistance to patriarchy, many of which are discussed in this chapter. This study concludes that it is the responsibility of women to resist patriarchy and to define roles for themselves. The three chapters examine various means of resistance and offer women insight into the forms of opposition they themselves can take.
- Full Text:
- Date Issued: 2001
- Authors: Hare, Nicola Tracy
- Date: 2001
- Subjects: Feminism in literature , Women's rights in literature , Feminism and literature , Patriarchy in literature
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:10986 , http://hdl.handle.net/10948/278 , Feminism in literature , Women's rights in literature , Feminism and literature , Patriarchy in literature
- Description: In the minds of many people all over the world, women are ‘second class citizens’, standing accused of the downfall of mankind ever since Eve allegedly ate the apple. Even amongst those who do not openly denigrate women, there are many who do so in other, more subtle ways even if they are unaware of it. This study proposes to challenge such a view of women by exposing the ways in which perceptions of women are constructed by society, which frequently wants to maintain the status quo of male dominance. This study employs a feminist approach in examining this gynocentric theme, along with cultural studies which, with its focus on power relations and ways of decentring power structures, is also clearly of use. In addition, this multidisciplinary approach of cultural studies offers the possibility of studying literary texts as well as popular culture. Three specific time periods are examined, with a view to uncovering negative perceptions of women and ways that women can resist such attempts to control them. In chapter one, the focus turns to contemporary perceptions of prehistoric women and the ways that so-called ‘objective’ science has failed to represent women accurately. Similarly, ‘objective’ accounts of Goddess-worship – which frequently fail to examine this phenomenon adequately – are revisited. Alice Walker’s The Temple of My Familiar (1989) is discussed as a text which acts as a site of resistance to societally-informed perceptions. Chapter two continues this investigation by turning to the concept of the witch and its maligned association with women. Woman and witchcraft, having been associated for centuries, are investigated as a pairing which frequently results because iii of attempts to control women by androcentric society. In such situations, the practising of witchcraft can actually become a form of resistance to patriarchy. The pernicious effect of society’s need to purge itself – by witch hunts – of witches is also investigated. The Devil’s Chimney (1997) by Anne Landsman and “The prophetess” (1994) by Njabulo S. Ndebele are discussed as texts which examine fictionalised South African versions of this phenomenon. Sinead O’Connor, the Irish singer, is the ‘bitch’ discussed in chapter three. She is examined as a woman who offers strong and on-going resistance to patriarchal ways of thinking which would ‘box’ women in. This singer refuses to accept societal roles which are offered to women and so offers means of resistance to patriarchy, many of which are discussed in this chapter. This study concludes that it is the responsibility of women to resist patriarchy and to define roles for themselves. The three chapters examine various means of resistance and offer women insight into the forms of opposition they themselves can take.
- Full Text:
- Date Issued: 2001
The identification of operations strategies based on business principles that will enhance the public sector's ability to retain its client departments
- Authors: Davids, Shahied
- Date: 2001
- Subjects: Eastern Cape (South Africa) -- Public Works Department , Customer services
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10941 , http://hdl.handle.net/10948/d1006192 , Eastern Cape (South Africa) -- Public Works Department , Customer services
- Description: The research problem addressed in this study was to identify operational strategies that will enhance the ability of National Public Works Department (NPWD) of the Eastern Cape to retain its Client Departments. Privatisation has lead to performance management becoming essential to satisfy the client departments needs and requirements. In order to identify operational strategies which will enhance NPWD’s operation’s performance, questionnaires with relevant operation questions were used as well as a brain-writing session. The findings of the literature survey clearly highlight the specific areas where attention is required for improvements.
- Full Text:
- Date Issued: 2001
- Authors: Davids, Shahied
- Date: 2001
- Subjects: Eastern Cape (South Africa) -- Public Works Department , Customer services
- Language: English
- Type: Thesis , Masters , MTech
- Identifier: vital:10941 , http://hdl.handle.net/10948/d1006192 , Eastern Cape (South Africa) -- Public Works Department , Customer services
- Description: The research problem addressed in this study was to identify operational strategies that will enhance the ability of National Public Works Department (NPWD) of the Eastern Cape to retain its Client Departments. Privatisation has lead to performance management becoming essential to satisfy the client departments needs and requirements. In order to identify operational strategies which will enhance NPWD’s operation’s performance, questionnaires with relevant operation questions were used as well as a brain-writing session. The findings of the literature survey clearly highlight the specific areas where attention is required for improvements.
- Full Text:
- Date Issued: 2001
The influence of a methylated-β-Cyclodextrin on the solubility and photostability of midazolam in aqueous solution
- Authors: Lebete, Mosimotsana Leah
- Date: 2001 , 2013-04-26
- Subjects: Midazolam -- Solubility
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3823 , http://hdl.handle.net/10962/d1005923 , Midazolam -- Solubility
- Description: Midazolam, used clinically as an anticonvulsant, anxiolytic, muscle relaxant and sedative is a photolabile imidazo-benzodiazepine which is marketed under the trade names Dormicum® and Hypnovel® as tablets and injectables. Because of an aqueous solubility of < 0.1 mg/ml above pH 4, the preparation of aqueous dosage formulations near physiological pH, requires a solubilizer. The aim of this study was thus to prepare a 10 mg/ml midazolam aqueous solution for topical application using randomly-methylated-pcyclodextrin (RAMEB), considered to be a suitable candidate as a solubilizer because of its absorption enhancing properties, and to investigate its effect on both the solubility and the photostability of midazolam. Solubility studies of midazolam (excess of 15 mg/ml) in the presence of 0, 5,10,20, 30% m/v of RAMEB at pH 5.0 and pH 5.8 (phosphate buffer) were undertaken and the results analyzed using a UV method validated for linearity, accuracy, precision and specificity. A stability-indicating HPLC method was developed and validated (precision and accuracy, linearity, range, limit of quantitation, specificity, robustness and ruggedness) for application to kinetic photostability studies and the identification of photodegradants by LC-MS. Forced degradation studies were carried out at concentrations of 0.5 mg/ml of midazolam instead of the target concentration of 10 mg/ml because of the acceleratory effect of the decreased concentration on the rate of photodegradation. The solutions of midazolam with and without RAMEB were irradiated at 550 W/m² for 12 hrs in order to degrade the drug to ± 10% of the original concentration. The UV method proved to be valid in terms of linearity with a correlation coefficient of 0.9998, precise and accurate, and specific for the determination of midazolam in the presence of RAMEB. The results of the phase solubility studies indicated that desired solubility of 10 mg/ml was achieved with 30% m/v RAMEB at pH 5.0. RAMEB slightly decreased the photostability of midazolam, the rate constants being 0.137 and 0.154 hr⁻¹ in the absence and presence of RAMEB, respectively. LC-MS analysis revealed that one of the major photoproducts in the presence and absence of RAMEB was N-desalkylflurazepam, a starting material in the synthesis of midazolam. RAMEB inhibited formation of some photoproducts and introduced two new photoproducts, a dimer and an addition product. The difference in the nature of these photoproducts formed may be attributed to the ability of RAMEB to provide conformational control and to stabilize free radicals. Although RAMEB improved the solubility of midazolam to the target concentration, photostability is decreased with the presence of different photoproducts. These studies have however provided information on the overall photostability of midazolam, the identity of its photodegradants and the photodegradation pathway in the presence and absence of RAMEB, and may be used for further method development and validation for the analysis of aqueous dosage forms containing RAMEB as a solubilizer. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2001
- Authors: Lebete, Mosimotsana Leah
- Date: 2001 , 2013-04-26
- Subjects: Midazolam -- Solubility
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3823 , http://hdl.handle.net/10962/d1005923 , Midazolam -- Solubility
- Description: Midazolam, used clinically as an anticonvulsant, anxiolytic, muscle relaxant and sedative is a photolabile imidazo-benzodiazepine which is marketed under the trade names Dormicum® and Hypnovel® as tablets and injectables. Because of an aqueous solubility of < 0.1 mg/ml above pH 4, the preparation of aqueous dosage formulations near physiological pH, requires a solubilizer. The aim of this study was thus to prepare a 10 mg/ml midazolam aqueous solution for topical application using randomly-methylated-pcyclodextrin (RAMEB), considered to be a suitable candidate as a solubilizer because of its absorption enhancing properties, and to investigate its effect on both the solubility and the photostability of midazolam. Solubility studies of midazolam (excess of 15 mg/ml) in the presence of 0, 5,10,20, 30% m/v of RAMEB at pH 5.0 and pH 5.8 (phosphate buffer) were undertaken and the results analyzed using a UV method validated for linearity, accuracy, precision and specificity. A stability-indicating HPLC method was developed and validated (precision and accuracy, linearity, range, limit of quantitation, specificity, robustness and ruggedness) for application to kinetic photostability studies and the identification of photodegradants by LC-MS. Forced degradation studies were carried out at concentrations of 0.5 mg/ml of midazolam instead of the target concentration of 10 mg/ml because of the acceleratory effect of the decreased concentration on the rate of photodegradation. The solutions of midazolam with and without RAMEB were irradiated at 550 W/m² for 12 hrs in order to degrade the drug to ± 10% of the original concentration. The UV method proved to be valid in terms of linearity with a correlation coefficient of 0.9998, precise and accurate, and specific for the determination of midazolam in the presence of RAMEB. The results of the phase solubility studies indicated that desired solubility of 10 mg/ml was achieved with 30% m/v RAMEB at pH 5.0. RAMEB slightly decreased the photostability of midazolam, the rate constants being 0.137 and 0.154 hr⁻¹ in the absence and presence of RAMEB, respectively. LC-MS analysis revealed that one of the major photoproducts in the presence and absence of RAMEB was N-desalkylflurazepam, a starting material in the synthesis of midazolam. RAMEB inhibited formation of some photoproducts and introduced two new photoproducts, a dimer and an addition product. The difference in the nature of these photoproducts formed may be attributed to the ability of RAMEB to provide conformational control and to stabilize free radicals. Although RAMEB improved the solubility of midazolam to the target concentration, photostability is decreased with the presence of different photoproducts. These studies have however provided information on the overall photostability of midazolam, the identity of its photodegradants and the photodegradation pathway in the presence and absence of RAMEB, and may be used for further method development and validation for the analysis of aqueous dosage forms containing RAMEB as a solubilizer. , KMBT_363 , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 2001
The influence of a performance management programme on the achievement of organisational and individual goals : a case study
- Authors: Van Huyssteen, Hannes
- Date: 2001
- Subjects: Performance -- Management , Goal setting in personnel management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10915 , http://hdl.handle.net/10948/63 , Performance -- Management , Goal setting in personnel management
- Description: Many organisations are continuously searching for methods which can be used to improve performance. One such method is by means of implementing a performance management programme. This research study addresses the influence that a performance management programme has on the achievement of organisational and individual performance. To achieve this objective a comprehensive literature study was performed to determine the views on performance, and on performance management programmes. The study also included an investigation into the extent to which a performance management programme should be aligned with organisational and individual goals. Questionnaires, developed from the literature study, were distributed amongst randomly selected respondents, in order to determine the extent to which a specific organisation manages performance, in line with the guidelines provided by the literature study. The information obtained from the questionnaires were compared with the guidelines provided by the literature study in order to identify shortcomings in the influence that the performance management programme has on the achievement of organisational and individual goals at the selected organisation. The final step of this study entailed the formulation of recommendations. Three of these recommendations are regarded as critical to ensure the successful improvement of performance by means of a performance management programme: Firstly, it is of utmost importance that training and development, and the necessary resources to achieve objectives is provided. Secondly, feedback forms an integral part of a performance management programme. Those who provide feedback, need to acquire the necessary skills, so as to ensure that both positive and negative feedback is given to employees, which could ultimately enhance performance. Thirdly, the success of a performance management programme resides with both management and employees. Management need to be committed to the programme, and the well-being of their employees. Management also needs to be able to eliminate problems that negatively influence performance. On the other hand, employees need to realise that a performance management programme is not only linked to pay, but also the development of each individual, and the improvement of performance.
- Full Text:
- Date Issued: 2001
- Authors: Van Huyssteen, Hannes
- Date: 2001
- Subjects: Performance -- Management , Goal setting in personnel management
- Language: English
- Type: Thesis , Masters , MBA
- Identifier: vital:10915 , http://hdl.handle.net/10948/63 , Performance -- Management , Goal setting in personnel management
- Description: Many organisations are continuously searching for methods which can be used to improve performance. One such method is by means of implementing a performance management programme. This research study addresses the influence that a performance management programme has on the achievement of organisational and individual performance. To achieve this objective a comprehensive literature study was performed to determine the views on performance, and on performance management programmes. The study also included an investigation into the extent to which a performance management programme should be aligned with organisational and individual goals. Questionnaires, developed from the literature study, were distributed amongst randomly selected respondents, in order to determine the extent to which a specific organisation manages performance, in line with the guidelines provided by the literature study. The information obtained from the questionnaires were compared with the guidelines provided by the literature study in order to identify shortcomings in the influence that the performance management programme has on the achievement of organisational and individual goals at the selected organisation. The final step of this study entailed the formulation of recommendations. Three of these recommendations are regarded as critical to ensure the successful improvement of performance by means of a performance management programme: Firstly, it is of utmost importance that training and development, and the necessary resources to achieve objectives is provided. Secondly, feedback forms an integral part of a performance management programme. Those who provide feedback, need to acquire the necessary skills, so as to ensure that both positive and negative feedback is given to employees, which could ultimately enhance performance. Thirdly, the success of a performance management programme resides with both management and employees. Management need to be committed to the programme, and the well-being of their employees. Management also needs to be able to eliminate problems that negatively influence performance. On the other hand, employees need to realise that a performance management programme is not only linked to pay, but also the development of each individual, and the improvement of performance.
- Full Text:
- Date Issued: 2001
The legal protection afforded to the consumer under current South African law with emphasis on the legal position in specific credit agreements contained in standard-form contracts
- Authors: Ndou, Fulufhelo Clyde
- Date: 2001
- Subjects: Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3688 , http://hdl.handle.net/10962/d1003203 , Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Description: The thesis covers the field of the contract law known as the consumer credit law. It deals with the legal protection afforded to the consumer under current South African law with emphasis on the legal position in specific credit agreements contained in standard-form contracts. The thesis focuses on those credit contracts in which the legal relationship between the consumer and the dominant party is contained in the standard-form contracts, specifically credit agreements relating to money lending transactions in which the credit grantor’s rights are secured either by means of mortgage agreement, a suretyship contract, or a deed of cession. In South Africa the right to equality and human dignity, as opposed to the classical theories of contract: pacta sunt servanda and the principle of freedom of contract, are supported by the Constitution of the Republic of South Africa Act 108 of 1996 which entrenched democratic values permeating all areas of the law including contract law. In this thesis the harmonisation of these classical theories of contract law and the constitutional values of human dignity and equality have been considered. As has been shown in a number of cases, notably those relating to the contracts of suretyship, cession in securitatem debiti, and mortgage, the current law regulating the relationship between the credit grantors and the credit receivers is in need of law reform to fall in line with the constitutional values of equality and human dignity. The greatest difficulty inherent in this area of the law is the reluctance of the courts to intervene at the instance of consumers. The courts would only intervene in the clearest of the cases, and would only do so in the public interest. In this thesis the current South African Law is considered in the light of the developments elsewhere. The tendency of credit providers to alter the terms of the contracts unilaterally and the growing number of conflicting decisions of the Provincial Divisions of High Court has also been considered. The writer also considers the role of the newly created Consumer Affairs Court.
- Full Text:
- Date Issued: 2001
- Authors: Ndou, Fulufhelo Clyde
- Date: 2001
- Subjects: Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Language: English
- Type: Thesis , Masters , LLM
- Identifier: vital:3688 , http://hdl.handle.net/10962/d1003203 , Consumer protection , Consumer protection -- Law and legislation -- South Africa
- Description: The thesis covers the field of the contract law known as the consumer credit law. It deals with the legal protection afforded to the consumer under current South African law with emphasis on the legal position in specific credit agreements contained in standard-form contracts. The thesis focuses on those credit contracts in which the legal relationship between the consumer and the dominant party is contained in the standard-form contracts, specifically credit agreements relating to money lending transactions in which the credit grantor’s rights are secured either by means of mortgage agreement, a suretyship contract, or a deed of cession. In South Africa the right to equality and human dignity, as opposed to the classical theories of contract: pacta sunt servanda and the principle of freedom of contract, are supported by the Constitution of the Republic of South Africa Act 108 of 1996 which entrenched democratic values permeating all areas of the law including contract law. In this thesis the harmonisation of these classical theories of contract law and the constitutional values of human dignity and equality have been considered. As has been shown in a number of cases, notably those relating to the contracts of suretyship, cession in securitatem debiti, and mortgage, the current law regulating the relationship between the credit grantors and the credit receivers is in need of law reform to fall in line with the constitutional values of equality and human dignity. The greatest difficulty inherent in this area of the law is the reluctance of the courts to intervene at the instance of consumers. The courts would only intervene in the clearest of the cases, and would only do so in the public interest. In this thesis the current South African Law is considered in the light of the developments elsewhere. The tendency of credit providers to alter the terms of the contracts unilaterally and the growing number of conflicting decisions of the Provincial Divisions of High Court has also been considered. The writer also considers the role of the newly created Consumer Affairs Court.
- Full Text:
- Date Issued: 2001
The mandibular gland secretions and ovarial development of worker honeybees (Apis Mellifera) in the Eastern Cape Province of South Africa
- Authors: Reece, Sacha Louise
- Date: 2001
- Subjects: Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5729 , http://hdl.handle.net/10962/d1005415 , Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Description: The Eastern Cape is an area in which Apis mellifera capensis, A. m. scutellata and their hybrid are known to naturally occur. I investigated the mandibular gland profiles and ovarial development of queenright workers from 4 localities. Their queens were then removed to determine how these aspects changed upon queen loss. In addition, drifted bees were analysed in the same way to determine how these factors changed once they had gained entry to a foreign hive. The queenright bees, form all 4 localities were found to have 9HDA as the most abundant of the 5 fatty acids measured and all localities had small percentages of 9ODA in their mandibular gland secretions. This resulted in relatively high queenright 9ODA:10HDA and 9HDA:10HDAA ratios. Despite this the percentage of bees with undeveloped ovaries was consistent with their queenright status. The mean values of these 2 ratios were significantly higher in the bees from East London and Cradock than those from Port Elizabeth. Steynsburg's bees were intermediate in this regard. Upon queen loss, the bees from all 4 localities had an increase in the percentage of 9ODA but the other compound changes in varying ways. East London's bees were the only ones not to become significantly more queen-like after queen loss. After 14 days without a queen, the mean values of these 2 ratios were much higher in the bees from Port Elizabeth than those from the other localities. Certain individuals from Port Elizabeth had values of these ratios that exceeded those found in A. m. capensis queens. Port Elizabeth was the only locality to display any surrogate queens and exhibited the highest increase in the number of bees with partially or fully developed ovaries. While certain individuals from the other localities had values of these ratios that exceeded these values reported in A. m. scutellata queens, Steynsburg's bees were the only ones that did increase in in terms of the number of bees with developed ovaries subsequent. The bees from Steynsburg were shown to suppress the mandibular gland and ovarial development of drifters from Port Elizabeth while bees from East London did not.
- Full Text:
- Date Issued: 2001
- Authors: Reece, Sacha Louise
- Date: 2001
- Subjects: Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5729 , http://hdl.handle.net/10962/d1005415 , Honeybee -- South Africa -- Eastern Cape , Honeybee -- Behavior , Honeybee -- Physiology
- Description: The Eastern Cape is an area in which Apis mellifera capensis, A. m. scutellata and their hybrid are known to naturally occur. I investigated the mandibular gland profiles and ovarial development of queenright workers from 4 localities. Their queens were then removed to determine how these aspects changed upon queen loss. In addition, drifted bees were analysed in the same way to determine how these factors changed once they had gained entry to a foreign hive. The queenright bees, form all 4 localities were found to have 9HDA as the most abundant of the 5 fatty acids measured and all localities had small percentages of 9ODA in their mandibular gland secretions. This resulted in relatively high queenright 9ODA:10HDA and 9HDA:10HDAA ratios. Despite this the percentage of bees with undeveloped ovaries was consistent with their queenright status. The mean values of these 2 ratios were significantly higher in the bees from East London and Cradock than those from Port Elizabeth. Steynsburg's bees were intermediate in this regard. Upon queen loss, the bees from all 4 localities had an increase in the percentage of 9ODA but the other compound changes in varying ways. East London's bees were the only ones not to become significantly more queen-like after queen loss. After 14 days without a queen, the mean values of these 2 ratios were much higher in the bees from Port Elizabeth than those from the other localities. Certain individuals from Port Elizabeth had values of these ratios that exceeded those found in A. m. capensis queens. Port Elizabeth was the only locality to display any surrogate queens and exhibited the highest increase in the number of bees with partially or fully developed ovaries. While certain individuals from the other localities had values of these ratios that exceeded these values reported in A. m. scutellata queens, Steynsburg's bees were the only ones that did increase in in terms of the number of bees with developed ovaries subsequent. The bees from Steynsburg were shown to suppress the mandibular gland and ovarial development of drifters from Port Elizabeth while bees from East London did not.
- Full Text:
- Date Issued: 2001
The mandibular gland secretions of the Cape honeybee (Apis mellifera capensis ESCH.) : factors affecting the production of the chemical signal and implications for further development of beekeeping in South Africa
- Authors: Jones, Georgina Elizabeth
- Date: 2001
- Subjects: Honeybee Honeybee -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5730 , http://hdl.handle.net/10962/d1005416
- Description: The chemical composition of the mandibular gland extracts of Apis mellifera capensis virgin queens was analysed by gas chromatography-mass spectroscopy. Thirty-seven compounds from various chemical groups including aliphatic and aromatic acids and diacids, phenols, alkanes, amino acids and sugars were identified. Among the identified compounds were the queen mandibular pheromone components 9ODA, 9HDA, HVA and HOB and the other aliphatic acids and phenols considered to be the major components of A.m. capensis mandibular glands. Ontogenetic changes in the concentration of the mandibular gland secretions of virgin queens were largely quantitative in nature with the total volume and that of most of the compounds increasing with queen age. The final level of 9ODA is reached at the premating stage, approximately three days after emergence, when it comprises approximately 87% of the major constituents of the mandibular gland signal. Hostile reactions by workers towards introduced virgin queens can be correlated to the relative proportion of 9ODA present in the mandibular gland secretions. This seems to indicate that it is the complete spectrum of the signal and not individual compounds that determine worker reaction towards introduced queens. Keeping queens singly, with or without workers, in an incubator and in small mating nucleus hives proved to be the most successful methods of queen rearing in respect to survival rate in A.m. capensis. The presence of workers during the ageing of virgin queens was found to significantly affect the chemical composition of the mandibular gland secretions of queens. The reaction of workers towards introduced virgin queens reared under different holding conditions varied, with queens reared with workers eliciting significantly less hostile reactions from workers than those reared without workers. Mated queens from five localities in the Eastern Cape were characterised on the basis of the chemical composition of their mandibular gland secretions and the ratio of 9ODA:10HDA. No significant differences were detected and none of the queens sampled could be considered to be A.m. capensis based on their mandibular gland signal. The findings of this study provide baseline data for the development of a queen-rearing program tailored to the specific requirements of A.m. capensis.
- Full Text:
- Date Issued: 2001
- Authors: Jones, Georgina Elizabeth
- Date: 2001
- Subjects: Honeybee Honeybee -- Physiology
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5730 , http://hdl.handle.net/10962/d1005416
- Description: The chemical composition of the mandibular gland extracts of Apis mellifera capensis virgin queens was analysed by gas chromatography-mass spectroscopy. Thirty-seven compounds from various chemical groups including aliphatic and aromatic acids and diacids, phenols, alkanes, amino acids and sugars were identified. Among the identified compounds were the queen mandibular pheromone components 9ODA, 9HDA, HVA and HOB and the other aliphatic acids and phenols considered to be the major components of A.m. capensis mandibular glands. Ontogenetic changes in the concentration of the mandibular gland secretions of virgin queens were largely quantitative in nature with the total volume and that of most of the compounds increasing with queen age. The final level of 9ODA is reached at the premating stage, approximately three days after emergence, when it comprises approximately 87% of the major constituents of the mandibular gland signal. Hostile reactions by workers towards introduced virgin queens can be correlated to the relative proportion of 9ODA present in the mandibular gland secretions. This seems to indicate that it is the complete spectrum of the signal and not individual compounds that determine worker reaction towards introduced queens. Keeping queens singly, with or without workers, in an incubator and in small mating nucleus hives proved to be the most successful methods of queen rearing in respect to survival rate in A.m. capensis. The presence of workers during the ageing of virgin queens was found to significantly affect the chemical composition of the mandibular gland secretions of queens. The reaction of workers towards introduced virgin queens reared under different holding conditions varied, with queens reared with workers eliciting significantly less hostile reactions from workers than those reared without workers. Mated queens from five localities in the Eastern Cape were characterised on the basis of the chemical composition of their mandibular gland secretions and the ratio of 9ODA:10HDA. No significant differences were detected and none of the queens sampled could be considered to be A.m. capensis based on their mandibular gland signal. The findings of this study provide baseline data for the development of a queen-rearing program tailored to the specific requirements of A.m. capensis.
- Full Text:
- Date Issued: 2001
The many faces of racism:
- Garman, Anthea, Baumann, Melissa
- Authors: Garman, Anthea , Baumann, Melissa
- Date: 2001
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158729 , vital:40223 , https://hdl.handle.net/10520/EJC144727
- Description: Last year South African journalists reluctantly agreed to examine themselves under the public spotlight when the Human Rights Commission decided to hold hearings into racism in the media.
- Full Text:
- Date Issued: 2001
- Authors: Garman, Anthea , Baumann, Melissa
- Date: 2001
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/158729 , vital:40223 , https://hdl.handle.net/10520/EJC144727
- Description: Last year South African journalists reluctantly agreed to examine themselves under the public spotlight when the Human Rights Commission decided to hold hearings into racism in the media.
- Full Text:
- Date Issued: 2001
The myth of authenticity : folktales and nationalism in the 'new South Africa'
- Authors: Naidu, Samantha
- Date: 2001
- Language: English
- Type: Article , text
- Identifier: vital:26378 , http://hdl.handle.net/10962/54047 , https://orcid.org/0000-0001-9456-8657
- Description: Folktales texts are published in glorious, polychromatic, innovative forms that promote the texts as both culturally educational and entertaining.
- Full Text: false
- Date Issued: 2001
- Authors: Naidu, Samantha
- Date: 2001
- Language: English
- Type: Article , text
- Identifier: vital:26378 , http://hdl.handle.net/10962/54047 , https://orcid.org/0000-0001-9456-8657
- Description: Folktales texts are published in glorious, polychromatic, innovative forms that promote the texts as both culturally educational and entertaining.
- Full Text: false
- Date Issued: 2001