Research portfolio
- Authors: Bock, L J
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia Curriculum change -- Namibia College teachers -- Training of -- Namibia Geography -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1895 , http://hdl.handle.net/10962/d1006128
- Full Text:
- Date Issued: 2004
- Authors: Bock, L J
- Date: 2004
- Subjects: Education -- Namibia Educational change -- Namibia Curriculum change -- Namibia College teachers -- Training of -- Namibia Geography -- Study and teaching (Secondary) -- Namibia
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1895 , http://hdl.handle.net/10962/d1006128
- Full Text:
- Date Issued: 2004
The effects of selected proline-based cyclic dipeptides on growth and induction of apoptosis in cancer cells
- Authors: Brauns, Seth Clint Aron
- Date: 2004
- Subjects: Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11088 , http://hdl.handle.net/10948/396 , Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Description: An increasing number of cyclic dipeptides (CDPs) have been shown to exhibit important biological activity including antifungal, antibacterial, anticonvulsant and immunomodulatory activity. Furthermore, some CDP derivatives have been shown to exhibit antitumour activity in vitro and in vivo. Several proline-based CDPs that exhibit biological activity have been detected in various processed foods and beverages. In the present study, the potential of seven proline-based CDPs to inhibit cancer cell growth was investigated in HT-29 (colon), HeLa (cervical), MCF-7 (breast) and WHCO3 (oesophageal) cancer cell lines. The CDPs used in this study were cyclo(Phe-Pro), cyclo(Tyr-Pro), cyclo(Gly-Pro), cyclo(Pro- Pro), cyclo(His-Pro), cyclo(Leu-Pro) and cyclo(Thr-Pro). The sulforhodamine B (SRB) cell growth assay was used in an initial screening phase to investigate the effects of the CDPs in HT-29, HeLa and MCF-7 cells. After exposing the cells to 10mM of the respective CDPs for 48 hours, the SRB assay results showed that only cyclo(Phe-Pro) exhibited more than 50% growth inhibition (p<0.01) in the three cell lines. The other CDPs showed comparatively marginal growth-inhibitory effects, except for cyclo(Tyr-Pro), which exhibited a pronounced effect in MCF-7 cells compared to HT-29 and HeLa cells. The MTT assay was used to confirm the SRB assay results for cyclo(Phe-Pro) and cyclo(Tyr-Pro), extending the investigation to the use of the fourth cell line WHCO3 and using a longer exposure time of 72 hours. The MTT assay demonstrated a dosedependent (0.008-10 mM) growth inhibition by cyclo(Phe-Pro) with an IC50 value of 4.04 ± 1.15 mM for HT-29 cells. Cyclo(Phe-Pro) was subsequently used to investigate whether the growth-inhibitory effects of this CDP were related to the induction of apoptosis in HT-29 cells. Hoechst 33342 staining showed that 5mM cyclo(Phe-Pro) induced characteristic chromatin condensation and nuclear fragmentation in 18.3 ± 2.8% (p<0.01) of HT-29 cells after 72 hours. Furthermore, annexin V binding revealed that HT-29 cells treated with 5 mM cyclo(Phe-Pro) displayed phosphatidylserine externalization after 48 hours. In addition, it was shown that 10 mM cyclo(Phe-Pro) induced poly(ADP-ribose)polymerase PARP cleavage, one of the hallmark events of apoptosis. The use of the broad-range caspase inhibitor Z-VAD-FMK, showed that this PARP cleavage was caspase-dependent, which in turn was confirmed by demonstrating an increase in caspase-3 activity (p<0.01) in cyclo(Phe- Pro)-treated HT-29 cells. In conclusion, these findings demonstrate that cyclo(Phe-Pro) inhibited the growth of HT- 29, MCF-7, HeLa and WHCO3 cells, and induced apoptosis in HT-29 colon cancer cells, suggesting the potential antitumour activity of cyclo(Phe-Pro)-related CDPs.
- Full Text:
- Date Issued: 2004
- Authors: Brauns, Seth Clint Aron
- Date: 2004
- Subjects: Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:11088 , http://hdl.handle.net/10948/396 , Cyclic peptides , Antineoplastic agents -- Testing , Apoptosis
- Description: An increasing number of cyclic dipeptides (CDPs) have been shown to exhibit important biological activity including antifungal, antibacterial, anticonvulsant and immunomodulatory activity. Furthermore, some CDP derivatives have been shown to exhibit antitumour activity in vitro and in vivo. Several proline-based CDPs that exhibit biological activity have been detected in various processed foods and beverages. In the present study, the potential of seven proline-based CDPs to inhibit cancer cell growth was investigated in HT-29 (colon), HeLa (cervical), MCF-7 (breast) and WHCO3 (oesophageal) cancer cell lines. The CDPs used in this study were cyclo(Phe-Pro), cyclo(Tyr-Pro), cyclo(Gly-Pro), cyclo(Pro- Pro), cyclo(His-Pro), cyclo(Leu-Pro) and cyclo(Thr-Pro). The sulforhodamine B (SRB) cell growth assay was used in an initial screening phase to investigate the effects of the CDPs in HT-29, HeLa and MCF-7 cells. After exposing the cells to 10mM of the respective CDPs for 48 hours, the SRB assay results showed that only cyclo(Phe-Pro) exhibited more than 50% growth inhibition (p<0.01) in the three cell lines. The other CDPs showed comparatively marginal growth-inhibitory effects, except for cyclo(Tyr-Pro), which exhibited a pronounced effect in MCF-7 cells compared to HT-29 and HeLa cells. The MTT assay was used to confirm the SRB assay results for cyclo(Phe-Pro) and cyclo(Tyr-Pro), extending the investigation to the use of the fourth cell line WHCO3 and using a longer exposure time of 72 hours. The MTT assay demonstrated a dosedependent (0.008-10 mM) growth inhibition by cyclo(Phe-Pro) with an IC50 value of 4.04 ± 1.15 mM for HT-29 cells. Cyclo(Phe-Pro) was subsequently used to investigate whether the growth-inhibitory effects of this CDP were related to the induction of apoptosis in HT-29 cells. Hoechst 33342 staining showed that 5mM cyclo(Phe-Pro) induced characteristic chromatin condensation and nuclear fragmentation in 18.3 ± 2.8% (p<0.01) of HT-29 cells after 72 hours. Furthermore, annexin V binding revealed that HT-29 cells treated with 5 mM cyclo(Phe-Pro) displayed phosphatidylserine externalization after 48 hours. In addition, it was shown that 10 mM cyclo(Phe-Pro) induced poly(ADP-ribose)polymerase PARP cleavage, one of the hallmark events of apoptosis. The use of the broad-range caspase inhibitor Z-VAD-FMK, showed that this PARP cleavage was caspase-dependent, which in turn was confirmed by demonstrating an increase in caspase-3 activity (p<0.01) in cyclo(Phe- Pro)-treated HT-29 cells. In conclusion, these findings demonstrate that cyclo(Phe-Pro) inhibited the growth of HT- 29, MCF-7, HeLa and WHCO3 cells, and induced apoptosis in HT-29 colon cancer cells, suggesting the potential antitumour activity of cyclo(Phe-Pro)-related CDPs.
- Full Text:
- Date Issued: 2004
A portfolio of original compositions with a commentary
- Authors: Nkuna, Musa
- Date: 2000
- Subjects: String quartets -- Scores Song cycles -- Scores Music -- Africa -- Scores
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: vital:2698 , http://hdl.handle.net/10962/d1018689
- Description: This portfolio consists of four diverse original compositions written in 1999 : a string quartet, a cello suite and a set of two choral pieces.
- Full Text:
- Date Issued: 2000
- Authors: Nkuna, Musa
- Date: 2000
- Subjects: String quartets -- Scores Song cycles -- Scores Music -- Africa -- Scores
- Language: English
- Type: text , Thesis , Masters , MMus
- Identifier: vital:2698 , http://hdl.handle.net/10962/d1018689
- Description: This portfolio consists of four diverse original compositions written in 1999 : a string quartet, a cello suite and a set of two choral pieces.
- Full Text:
- Date Issued: 2000
An investigation into the effect of military influences on the theology and form of The Spiritual Exercise of Ignatius of Loyola
- Authors: Christie, David Osborne
- Date: 1999
- Subjects: Ignatius, of Loyola, Saint, 1491-1556. Exercitia spiritualia
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1241 , http://hdl.handle.net/10962/d1008540
- Description: The purpose of this thesis is to investigate the influences of a military nature affecting the life of Ignatius of Loyola up to the time he wrote The Spiritual Exercises, and to assess whether such influences may have affected the theology and form of The Spiritual Exercises. The investigation opens with an apologetic on why the author considers it desirable to examine The Spiritual Exercises from this point of view. Thereafter a review of the life of Ignatius up to the time he wrote The Exercises is undertaken to identify which sources may have provided influences of a military nature or nuance, and to examine what possible effect these had upon Ignatius. The potential sources of influence examined include Ignatius's family background and the milieu in which he grew up, the attitude of his mentors in particular and society in general to the profession of arms, and Ignatius's own response to this attitude. From the age of twenty-five to thirty Ignatius was employed on duties of a principally military nature until he was severely wounded at the Battle of Pamplona in 1521. Therefore his military experience is examined together with an attempt to assess the degree, if any, of his spirituality at that point in his life. This is followed by an investigation of the literary sources available to Ignatius from the time of his wounding up to the time when he wrote The Spiritual Exercises at Manresa. Thereafter an examination of the changes which took place in his psyche and spirit, from the time he was wounded up to the time he wrote The Spiritual Exercises is undertaken, in order to ascertain whether his attitude to military concepts immediately prior to writing The Exercises had changed from his pre-Pamplona days. The Spiritual Exercises are then examined to consider which portions, if any, were affected in form or theology by military influences or nuances. The conclusion reached is that whereas The Spiritual Exercises are in no way a military treatise, the form is affected to a reasonable degree by Ignatius's experiences of, and attitude to, the military life, whereas the theology is affected only slightly.
- Full Text:
- Date Issued: 1999
- Authors: Christie, David Osborne
- Date: 1999
- Subjects: Ignatius, of Loyola, Saint, 1491-1556. Exercitia spiritualia
- Language: English
- Type: Thesis , Masters , MTh
- Identifier: vital:1241 , http://hdl.handle.net/10962/d1008540
- Description: The purpose of this thesis is to investigate the influences of a military nature affecting the life of Ignatius of Loyola up to the time he wrote The Spiritual Exercises, and to assess whether such influences may have affected the theology and form of The Spiritual Exercises. The investigation opens with an apologetic on why the author considers it desirable to examine The Spiritual Exercises from this point of view. Thereafter a review of the life of Ignatius up to the time he wrote The Exercises is undertaken to identify which sources may have provided influences of a military nature or nuance, and to examine what possible effect these had upon Ignatius. The potential sources of influence examined include Ignatius's family background and the milieu in which he grew up, the attitude of his mentors in particular and society in general to the profession of arms, and Ignatius's own response to this attitude. From the age of twenty-five to thirty Ignatius was employed on duties of a principally military nature until he was severely wounded at the Battle of Pamplona in 1521. Therefore his military experience is examined together with an attempt to assess the degree, if any, of his spirituality at that point in his life. This is followed by an investigation of the literary sources available to Ignatius from the time of his wounding up to the time when he wrote The Spiritual Exercises at Manresa. Thereafter an examination of the changes which took place in his psyche and spirit, from the time he was wounded up to the time he wrote The Spiritual Exercises is undertaken, in order to ascertain whether his attitude to military concepts immediately prior to writing The Exercises had changed from his pre-Pamplona days. The Spiritual Exercises are then examined to consider which portions, if any, were affected in form or theology by military influences or nuances. The conclusion reached is that whereas The Spiritual Exercises are in no way a military treatise, the form is affected to a reasonable degree by Ignatius's experiences of, and attitude to, the military life, whereas the theology is affected only slightly.
- Full Text:
- Date Issued: 1999
The design and use of a data base for the teaching of history at primary school level
- Authors: Paul, James R M
- Date: 1994
- Subjects: Education -- Data processing History -- Study and teaching (Elementary) -- Data processing Computer-assisted instruction
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1490 , http://hdl.handle.net/10962/d1003371
- Description: The changes brought about by society's move from an industrial to an information society has brought with it changes in the way that society operates - from the way we do business to the way we entertain ourselves and, increasingly, in the way we educate our children. That the society of tomorrow requires new skills to survive and operate had been, and continues to be, debated in a growing number of books and in the popular media. More and more educationists are calling for schools to 'restructure' so as to be able to provide the skills that this new society requires, especially those related to the management of information. The nature of these skills are discussed, together with the potential provided by information technology, particularly computers, to provide them. The current use of computers in schools is addressed, together with the apparent inability of schools to generate effective change from within using in-service training. The researcher suggests that this makes it imperative that teacher training institutions provide the next generation of teacher-trainees with a thorough understanding of the requirements of an information society and the tools that it uses. The research undertaken attempted to provide final year primary education teacher-trainees with one example of the way in which the electronic database can be used to change the teaching of history. By researching in the field and entering data into a data base, the teacher-trainees were able to look at information in new ways. By selecting and sorting data by different fields, they were able to act as ' true' historians - each interacting with the data in his or her own way to extract knowledge that is arguably unique for each participant. The data base was then used with a class of standard four pupils, with the researcher acting as participant observer. The reactions and responses of the pupils to the data was noted and these are discussed in the results . A non-participant observer, also a primary school history -teacher, provided input with respect to the validity of the learning experience and to act as a control. The research is described, together with the observations of the researcher, teacher-trainees and pupils involved. The observations of the non-participant observer are also discussed. Shortfalls and difficulties encountered are pointed out, and areas for further research suggested.
- Full Text:
- Date Issued: 1994
- Authors: Paul, James R M
- Date: 1994
- Subjects: Education -- Data processing History -- Study and teaching (Elementary) -- Data processing Computer-assisted instruction
- Language: English
- Type: Thesis , Masters , MEd
- Identifier: vital:1490 , http://hdl.handle.net/10962/d1003371
- Description: The changes brought about by society's move from an industrial to an information society has brought with it changes in the way that society operates - from the way we do business to the way we entertain ourselves and, increasingly, in the way we educate our children. That the society of tomorrow requires new skills to survive and operate had been, and continues to be, debated in a growing number of books and in the popular media. More and more educationists are calling for schools to 'restructure' so as to be able to provide the skills that this new society requires, especially those related to the management of information. The nature of these skills are discussed, together with the potential provided by information technology, particularly computers, to provide them. The current use of computers in schools is addressed, together with the apparent inability of schools to generate effective change from within using in-service training. The researcher suggests that this makes it imperative that teacher training institutions provide the next generation of teacher-trainees with a thorough understanding of the requirements of an information society and the tools that it uses. The research undertaken attempted to provide final year primary education teacher-trainees with one example of the way in which the electronic database can be used to change the teaching of history. By researching in the field and entering data into a data base, the teacher-trainees were able to look at information in new ways. By selecting and sorting data by different fields, they were able to act as ' true' historians - each interacting with the data in his or her own way to extract knowledge that is arguably unique for each participant. The data base was then used with a class of standard four pupils, with the researcher acting as participant observer. The reactions and responses of the pupils to the data was noted and these are discussed in the results . A non-participant observer, also a primary school history -teacher, provided input with respect to the validity of the learning experience and to act as a control. The research is described, together with the observations of the researcher, teacher-trainees and pupils involved. The observations of the non-participant observer are also discussed. Shortfalls and difficulties encountered are pointed out, and areas for further research suggested.
- Full Text:
- Date Issued: 1994
The interpersonal dimension of psychopathology
- Authors: O'Dowd, S A
- Date: 1987
- Subjects: Psychology, Pathological
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2910 , http://hdl.handle.net/10962/d1002075
- Description: It is argued that two large groups of disorders can be distinguished in the field of psychopathology, (1) which divide between them the psychoses, neuroses and personality disorders; ( 2) the dynamics of which are those of Klein's paranoid-schizoid and depressive positions, respectively; and (3) which are distinguished by nine basic contrasts in symptomatology and dynamics, all of which are expressive of the opposition self-centred/other-centred. These three hypotheses form the interpersonal model of psychopathology, and are supported by argument from works of Foulds, Jung, Abraham, Fairbairn, Klein, Angyal, Winnicott and Heidegger. It is suggested that the interpersonal model can facilitate the dialogue between psychoanalysis and phenomenology
- Full Text:
- Date Issued: 1987
- Authors: O'Dowd, S A
- Date: 1987
- Subjects: Psychology, Pathological
- Language: English
- Type: Thesis , Masters , MA
- Identifier: vital:2910 , http://hdl.handle.net/10962/d1002075
- Description: It is argued that two large groups of disorders can be distinguished in the field of psychopathology, (1) which divide between them the psychoses, neuroses and personality disorders; ( 2) the dynamics of which are those of Klein's paranoid-schizoid and depressive positions, respectively; and (3) which are distinguished by nine basic contrasts in symptomatology and dynamics, all of which are expressive of the opposition self-centred/other-centred. These three hypotheses form the interpersonal model of psychopathology, and are supported by argument from works of Foulds, Jung, Abraham, Fairbairn, Klein, Angyal, Winnicott and Heidegger. It is suggested that the interpersonal model can facilitate the dialogue between psychoanalysis and phenomenology
- Full Text:
- Date Issued: 1987
An examination of Aristotelian modality
- Authors: Munshi, Salma
- Date: 1986
- Subjects: Aristotle , Modality (Theory of knowledge)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2703 , http://hdl.handle.net/10962/d1001978
- Description: From introduction: A popular misconception regarding Aristotle's views on modality is that Aristotle adhered to the doctrine of no unrealized possibilities. According to this doctrine, all possibilities are realized in time; in other words, if it is possible that something could happen, then at some time it is the case that that happens. For example, if it is possible for Socrates to escape from prison, then there will be a time at which Socrates will actually escape from prison. On this view, the possible and the actual co-incide; whereas there is abundant evidence that Aristotle was careful to maintain a distinction between the possible and the actual.
- Full Text:
- Date Issued: 1986
- Authors: Munshi, Salma
- Date: 1986
- Subjects: Aristotle , Modality (Theory of knowledge)
- Language: English
- Type: text , Thesis , Masters , MA
- Identifier: vital:2703 , http://hdl.handle.net/10962/d1001978
- Description: From introduction: A popular misconception regarding Aristotle's views on modality is that Aristotle adhered to the doctrine of no unrealized possibilities. According to this doctrine, all possibilities are realized in time; in other words, if it is possible that something could happen, then at some time it is the case that that happens. For example, if it is possible for Socrates to escape from prison, then there will be a time at which Socrates will actually escape from prison. On this view, the possible and the actual co-incide; whereas there is abundant evidence that Aristotle was careful to maintain a distinction between the possible and the actual.
- Full Text:
- Date Issued: 1986
An examination of the extractives of Leonotis species
- Authors: Kaplan, Errol R
- Date: 1966
- Subjects: Leonotis -- Analysis Botanical chemistry Chemistry, Analytic Chemistry, Organic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4481 , http://hdl.handle.net/10962/d1012628
- Description: Marrubiin and the other two diterpenoids, compounds X and Y, which had previously been isolated from Leonotus leonurus have been reinvestigated. Although the structure for marrubiin is well known its stereochemistry has been the subject of protracted discussion and is by no means secure except at C₅ and C₁₀ . N.M.R. spectral evidence showed that the lactone ring was cis-fused and β-orientated. Dehydration experiments carried out by previous workers were repeated, in order to resolve the residual uncertainty regarding the stereochemistry at C₉, an attempt was made to prepare iodoacetyl marrubic acid for X-ray crystallographic studies. Compound Y, C₂₀H₂₈0₃, a triply-unsaturated compound was shown by spectral studies to contain a furan ring and an α,β- unsaturated keto-group. It possesses a hydroxyl group incapable of acetylation, but readily removed by alkali and dehydrating agents to yield a tetraunsaturated compound, anhydro~Y; the hydroxyl is thus tertiary, Isolation of 1:2:5-trimethylnaphthalene on dehydrogenation indicated a relationship with the labdane diterpene group and supported the C₂₀ formula, The position of the α,β-unsaturated keto-group was resolved by interpretation of the ultraviolet spectra of degradation products and also by isolation of 1:2:3:5- trimethylnaphthalene on dehydrogenation of a suitable grignard product, The presence of a β-substituted furan was further indicated by colour reactions and confirmed by mass and n.m.r. spectra. The skeleton of compound Y is correlated with marrubiin via "iso-ambreinolide " and its stereochemistry is discussed. Further stereochemical assignments are postulated from the study of the n.m.r. spectra. Compound X, C₂₀H₂₈0₅, was shown by spectral and chemical evidence to be a diterpenoid dilactone containing an ether bridge between C₉ and C₁₃ Isolation of 1:2:5 trimethylnaphthal ene on dehydrogenation showed it to be closely related to marrubiin, This was supported by n.m.r. spectral results. A structure for compound X is proposed and the stereochemistry discussed. The aerial portions of Leonotis leonitis were also extracted and shown to contain a new compound, compound R. Preliminary investigation showed that it was a dilactone containing a furan ring, The n.m.r. spectrum of the compound is discussed.
- Full Text:
- Date Issued: 1966
- Authors: Kaplan, Errol R
- Date: 1966
- Subjects: Leonotis -- Analysis Botanical chemistry Chemistry, Analytic Chemistry, Organic
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4481 , http://hdl.handle.net/10962/d1012628
- Description: Marrubiin and the other two diterpenoids, compounds X and Y, which had previously been isolated from Leonotus leonurus have been reinvestigated. Although the structure for marrubiin is well known its stereochemistry has been the subject of protracted discussion and is by no means secure except at C₅ and C₁₀ . N.M.R. spectral evidence showed that the lactone ring was cis-fused and β-orientated. Dehydration experiments carried out by previous workers were repeated, in order to resolve the residual uncertainty regarding the stereochemistry at C₉, an attempt was made to prepare iodoacetyl marrubic acid for X-ray crystallographic studies. Compound Y, C₂₀H₂₈0₃, a triply-unsaturated compound was shown by spectral studies to contain a furan ring and an α,β- unsaturated keto-group. It possesses a hydroxyl group incapable of acetylation, but readily removed by alkali and dehydrating agents to yield a tetraunsaturated compound, anhydro~Y; the hydroxyl is thus tertiary, Isolation of 1:2:5-trimethylnaphthalene on dehydrogenation indicated a relationship with the labdane diterpene group and supported the C₂₀ formula, The position of the α,β-unsaturated keto-group was resolved by interpretation of the ultraviolet spectra of degradation products and also by isolation of 1:2:3:5- trimethylnaphthalene on dehydrogenation of a suitable grignard product, The presence of a β-substituted furan was further indicated by colour reactions and confirmed by mass and n.m.r. spectra. The skeleton of compound Y is correlated with marrubiin via "iso-ambreinolide " and its stereochemistry is discussed. Further stereochemical assignments are postulated from the study of the n.m.r. spectra. Compound X, C₂₀H₂₈0₅, was shown by spectral and chemical evidence to be a diterpenoid dilactone containing an ether bridge between C₉ and C₁₃ Isolation of 1:2:5 trimethylnaphthal ene on dehydrogenation showed it to be closely related to marrubiin, This was supported by n.m.r. spectral results. A structure for compound X is proposed and the stereochemistry discussed. The aerial portions of Leonotis leonitis were also extracted and shown to contain a new compound, compound R. Preliminary investigation showed that it was a dilactone containing a furan ring, The n.m.r. spectrum of the compound is discussed.
- Full Text:
- Date Issued: 1966