Student's van Hiele levels of geometric thought and conception in plane geometry: a collective case study of Nigeria and South Africa
- Authors: Atebe, Humphrey Uyouyo
- Date: 2009
- Subjects: Geometry -- Study and teaching (Secondary) -- Nigeria -- Case studies Geometry -- Study and teaching (Secondary) -- South Africa -- Case studies Mathematics -- Study and teaching (Secondary) -- Nigeria -- Case studies Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1777 , http://hdl.handle.net/10962/d1003662
- Description: This study is inspired by and utilises the van Hiele theory of geometric thought levels, currently acclaimed as one of the best frameworks for studying teaching and learning processes in geometry. The study aims both to explore and explicate the van Hiele levels of geometric thinking of a selected group of grade 10, 11 and 12 learners in Nigerian and South African schools. The study further aims to provide a rich and indepth description of the geometry instructional practices that possibly contributed to the levels of geometric conceptualisation exhibited by this cohort of high school learners. This collective case study, presented in two volumes, is oriented within an interpretive research paradigm and characterised by both qualitative and quantitative methods. The sample for the study comprised a total of 144 mathematics learners and 6 mathematics teachers from Nigeria and South Africa. They were selected using both purposive and stratified sampling techniques. In using the van Hiele model to interrogate both learners’ levels of geometric conceptualisation and teaching methods in geometry classrooms, the study employs a qualitative and qunatitative approach to the data-collection process, involving the use of questionnaires (in the form of various pen-and-paper tests, hands-on activity-based tests), interviews and classroom videos. Although the data analysis was done largely through descriptive statistics, the whole process inevitably incorporated elements of inferential statistics (e.g. ANOVA and Tukey HSD post-hoc test) in the quest for indepth analysis and deeper interpretation of the data. Learners were assigned to various van Hiele levels, mainly according to Usiskin’s (1982) forced van Hiele level determination scheme. The whole process of analysing the classroom videos involved a consultative panel of 4 observers and 3 critical readers, using the checklist of van Hiele phase descriptors to guide the analysis process. Concerning learners’ levels of geometric conceptualisation, the results from this study reveal that the most of the learners were not yet ready for the formal deductive study of school geometry, as only 2% and 3% of them were respectively at van Hiele levels 3 and 4, while 47%, 22% and 24% were at levels 0, 1 and 2, respectively. More learners from the Nigerian subsample (53%) were at van Hiele level 0 than learners from the South African subsample (41%) at this level. No learner from the Nigerian subsample was at van Hiele level 4, while 6% of the South African learners were at level 4. In general, learners from the Nigerian subsample had a poorer knowledge of school geometry than their peers from the South African subsample, as learners from the latter subsample obtained significantly higher mean scores in the van Hiele Geometry Test (VHGT) and each of the other tests used in this study. Results relating to gender differences in performance generally favour the male learners in this study. For each of the participating schools, learners’ van Hiele levels (as determined by their scores on the VHGT) strongly correlate with their performance in geometry content tests and mathematics generally. For each of the Nigerian and South African subsamples, for n ≤ 2, learners at van Hiele level n obtained higher means on nearly all the tests administered in this study than their peers at level n–1. This finding provides support for the hierarchical property of the van Hiele levels.
- Full Text:
- Date Issued: 2009
- Authors: Atebe, Humphrey Uyouyo
- Date: 2009
- Subjects: Geometry -- Study and teaching (Secondary) -- Nigeria -- Case studies Geometry -- Study and teaching (Secondary) -- South Africa -- Case studies Mathematics -- Study and teaching (Secondary) -- Nigeria -- Case studies Mathematics -- Study and teaching (Secondary) -- South Africa -- Case studies
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:1777 , http://hdl.handle.net/10962/d1003662
- Description: This study is inspired by and utilises the van Hiele theory of geometric thought levels, currently acclaimed as one of the best frameworks for studying teaching and learning processes in geometry. The study aims both to explore and explicate the van Hiele levels of geometric thinking of a selected group of grade 10, 11 and 12 learners in Nigerian and South African schools. The study further aims to provide a rich and indepth description of the geometry instructional practices that possibly contributed to the levels of geometric conceptualisation exhibited by this cohort of high school learners. This collective case study, presented in two volumes, is oriented within an interpretive research paradigm and characterised by both qualitative and quantitative methods. The sample for the study comprised a total of 144 mathematics learners and 6 mathematics teachers from Nigeria and South Africa. They were selected using both purposive and stratified sampling techniques. In using the van Hiele model to interrogate both learners’ levels of geometric conceptualisation and teaching methods in geometry classrooms, the study employs a qualitative and qunatitative approach to the data-collection process, involving the use of questionnaires (in the form of various pen-and-paper tests, hands-on activity-based tests), interviews and classroom videos. Although the data analysis was done largely through descriptive statistics, the whole process inevitably incorporated elements of inferential statistics (e.g. ANOVA and Tukey HSD post-hoc test) in the quest for indepth analysis and deeper interpretation of the data. Learners were assigned to various van Hiele levels, mainly according to Usiskin’s (1982) forced van Hiele level determination scheme. The whole process of analysing the classroom videos involved a consultative panel of 4 observers and 3 critical readers, using the checklist of van Hiele phase descriptors to guide the analysis process. Concerning learners’ levels of geometric conceptualisation, the results from this study reveal that the most of the learners were not yet ready for the formal deductive study of school geometry, as only 2% and 3% of them were respectively at van Hiele levels 3 and 4, while 47%, 22% and 24% were at levels 0, 1 and 2, respectively. More learners from the Nigerian subsample (53%) were at van Hiele level 0 than learners from the South African subsample (41%) at this level. No learner from the Nigerian subsample was at van Hiele level 4, while 6% of the South African learners were at level 4. In general, learners from the Nigerian subsample had a poorer knowledge of school geometry than their peers from the South African subsample, as learners from the latter subsample obtained significantly higher mean scores in the van Hiele Geometry Test (VHGT) and each of the other tests used in this study. Results relating to gender differences in performance generally favour the male learners in this study. For each of the participating schools, learners’ van Hiele levels (as determined by their scores on the VHGT) strongly correlate with their performance in geometry content tests and mathematics generally. For each of the Nigerian and South African subsamples, for n ≤ 2, learners at van Hiele level n obtained higher means on nearly all the tests administered in this study than their peers at level n–1. This finding provides support for the hierarchical property of the van Hiele levels.
- Full Text:
- Date Issued: 2009
The coordination chemistry of Rhenium(V) with multidentate no-donor ligands
- Authors: Abrahams, Abubak'r
- Date: 2009
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10370 , http://hdl.handle.net/10948/912 , Rhenium , Ligands
- Description: The neutral distorted octahedral complexes [ReOCl(L)] {H2L = N,N-bis(2- hydroxybenzyl)-2-(2-aminoethyl)dimethylamine (H2had), N,N-bis(2-hydroxybenzyl) aminomethylpyridine (H2hap); N,N-bis(2-hydroxybenzyl)-2-(2-aminoethyl)pyridine (H2hae)} were prepared by the reaction of trans-[ReOCl3(PPh3)2] with a twofold molar excess of H2L in ethanol. The X-ray structure determinations of [ReOCl(had)] and [ReOCl(hap)] were performed, and in both complexes the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen. Treatment of trans-[ReO2(py)4]I with two equivalents and one equivalent each of H2had in acetone afforded the iodide salts of the oxypyridinium-ammonium zwitterions N1-(2-hydroxybenzyl)-N2,N2- dimethyl-N1-((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [Hhpd]+ and N2,N2- dimethyl-N1-bis((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [dod]+ respectively. In [Hhpd]I, one of the 2-hydroxyphenyl groups of H2had is substituted by an oxypyridinium group, and in [dod]I, both 2-hydroxyphenyl groups are converted. The X-ray crystal structure determination of the starting material H2had, [Hhpd]I and [dod]I reveals trigonal pyramidal geometries around the central amino nitrogen. The complex salt [ReO(bsa)]PF6 (H2bsa=bis(N-methylsalicylicylideneiminopropyl) amine) was prepared from the reaction of cis-[ReO2I(PPh3)2] with H2bsa in toluene. The dianionic pentadentate ligand bsa is coordinated to the ReO3+ moiety via one secondary amino and two imino nitrogens, and two anionic phenolate oxygens. The complex was characterized by spectroscopy and analytical data, and the structure has been determined by single-crystal X-ray diffraction analysis. The complex exhibits a distorted octahedral geometry around the central rhenium(V) ion, with the basal plane being defined by a phenolate oxygen, two imino nitrogens and the secondary amino. ix A. Abrahams Nelson Mandela Metropolitan University The reaction of a two-fold molar excess of the potentially NN-donor ligand 2,2’- dipyridylamine (dpa) with trans-[ReO(OEt)Cl2(PPh3)2] in ethanol led to the isolation of [ReOCl2(OEt)(dpa)]. The X-ray crystal structure shows that the NN-chelated dpa is coordinated in the equatorial plane cis to the oxo and ethoxo groups, which are in trans positions relative to each other. The treatment of trans- [ReOCl3(PPh3)2] with a tenfold molar excess of dpa in ethanol at the refluxing temperature yielded the trans-dioxo complex [ReO2(dpa)2]Cl, but with a twofold molar excess only (μ-O)[{ReOCl2(dpa)}2] was isolated. Repeating the latter reaction with (n-Bu4N)[ReOCl4] as starting material in ethanol at room temperature a dark green product, also with the formulation (μ-O)[{ReOCl2(dpa)}2], was isolated. The reaction of equimolar quantities of bis(pyridin-2-yl)methyl)amine (HBPA) with (n-Bu4N)[ReOCl4] in acetone at room temperature led to the isolation of the sixcoordinate rhenium(V) complex [ReOCl(H2O)(BPA)]Cl. IR, NMR and X-ray crystallographic results indicate that BPA is coordinated as a tridentate uninegative chelate, with deprotonation of the amine nitrogen. The water molecule is coordinated trans to the oxo group, with the Re=O and Re-OH2 bond distances equal to 1.663(9) and 2.21(1) Å respectively. Complexes of the general formula [ReOX2{(C5H4N)CH(O)CH2(C5H4N)}] (X = Cl, I) were prepared by the reactions of trans-[ReOCl3(PPh3)2] and trans- [ReOI2(OEt)(PPh3)2] with cis-1,2-di-(2-pyridyl)ethylene (DPE) in ethanol and benzene in air. Experimental evidence shows that the coordinated DPE ligand has undergone addition of water at the ethylenic carbons, and that the (C5H4N)CH(O)CH2(C5H4N) moiety acts as a uninegative tridentate NON-donor ligand. The X-ray crystal structures of both complexes show a distorted octahedral geometry around the rhenium(V) centre. The treatment of trans-[ReOCl3(PPh3)2] with H2dbd in a 2:1 molar ratio in acetonitrile led to the isolation of the ligand-bridged dimer (μ-dbd)[ReOCl2(PPh3)]2. The X-ray crystal structure of the complex reveals a dinuclear structure in which two rhenium(V) ions are bridged by the dbd ligand. Each rhenium ion is in a x A. Abrahams Nelson Mandela Metropolitan University distorted octahedral geometry. The basal plane is defined by a phosphorus atom of the PPh3 group, two chlorides cis to each other, and a pyridyl nitrogen atom of dbd. The oxo group and alcoholate oxygen of dbd lie in trans axial positions. The complexes cis-[ReOX2(msa)(PPh3)] (X = Cl, Br, I) were prepared from trans- [ReOCl3(PPh3)2], trans-[ReOBr3(PPh3)2] or trans-[ReOI2(OEt)(PPh3)2] with 2-(1- iminoethyl)phenol (Hmsa) in acetonitrile. An X-ray crystallographic study shows that the bonding distances and angles in the comlexes are nearly identical, and that the two halides in each complex are coordinated cis to each other in the equatorial plane cis to the oxo group. The oxo-bridged dinuclear rhenium(V) complex [(μ-O){ReOCl(amp)}2] was prepared by the reaction of trans-[ReOCl3(PPh3)2] and 6-amino-3-methyl-1-phenyl- 4-azahept-2-ene-1-one (Hamp) in acetone. The characterization of the complex by elemental analysis, infrared and 1H NMR spectroscopy and X-ray crystallography shows that amp is coordinated as a monoanionic NNO-donor chelate as an amino-amido ketone. However, the reaction of the similar ligand 7- amino-4,7-dimethyl-5-aza-3-octen-2-one (Hada) with [Re(CO)5Br] produced the product fac-[Re(CO)3Br(Hada)], with Hada coordinated as a neutral NN-donor amino-imino-ketone.
- Full Text:
- Date Issued: 2009
- Authors: Abrahams, Abubak'r
- Date: 2009
- Subjects: Rhenium , Ligands
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10370 , http://hdl.handle.net/10948/912 , Rhenium , Ligands
- Description: The neutral distorted octahedral complexes [ReOCl(L)] {H2L = N,N-bis(2- hydroxybenzyl)-2-(2-aminoethyl)dimethylamine (H2had), N,N-bis(2-hydroxybenzyl) aminomethylpyridine (H2hap); N,N-bis(2-hydroxybenzyl)-2-(2-aminoethyl)pyridine (H2hae)} were prepared by the reaction of trans-[ReOCl3(PPh3)2] with a twofold molar excess of H2L in ethanol. The X-ray structure determinations of [ReOCl(had)] and [ReOCl(hap)] were performed, and in both complexes the chloride is coordinated trans to the tripodal tertiary amino nitrogen, with a phenolate oxygen trans to the oxo oxygen. Treatment of trans-[ReO2(py)4]I with two equivalents and one equivalent each of H2had in acetone afforded the iodide salts of the oxypyridinium-ammonium zwitterions N1-(2-hydroxybenzyl)-N2,N2- dimethyl-N1-((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [Hhpd]+ and N2,N2- dimethyl-N1-bis((2-oxypyridinium)-1-methyl)ethane-1,2-diamine [dod]+ respectively. In [Hhpd]I, one of the 2-hydroxyphenyl groups of H2had is substituted by an oxypyridinium group, and in [dod]I, both 2-hydroxyphenyl groups are converted. The X-ray crystal structure determination of the starting material H2had, [Hhpd]I and [dod]I reveals trigonal pyramidal geometries around the central amino nitrogen. The complex salt [ReO(bsa)]PF6 (H2bsa=bis(N-methylsalicylicylideneiminopropyl) amine) was prepared from the reaction of cis-[ReO2I(PPh3)2] with H2bsa in toluene. The dianionic pentadentate ligand bsa is coordinated to the ReO3+ moiety via one secondary amino and two imino nitrogens, and two anionic phenolate oxygens. The complex was characterized by spectroscopy and analytical data, and the structure has been determined by single-crystal X-ray diffraction analysis. The complex exhibits a distorted octahedral geometry around the central rhenium(V) ion, with the basal plane being defined by a phenolate oxygen, two imino nitrogens and the secondary amino. ix A. Abrahams Nelson Mandela Metropolitan University The reaction of a two-fold molar excess of the potentially NN-donor ligand 2,2’- dipyridylamine (dpa) with trans-[ReO(OEt)Cl2(PPh3)2] in ethanol led to the isolation of [ReOCl2(OEt)(dpa)]. The X-ray crystal structure shows that the NN-chelated dpa is coordinated in the equatorial plane cis to the oxo and ethoxo groups, which are in trans positions relative to each other. The treatment of trans- [ReOCl3(PPh3)2] with a tenfold molar excess of dpa in ethanol at the refluxing temperature yielded the trans-dioxo complex [ReO2(dpa)2]Cl, but with a twofold molar excess only (μ-O)[{ReOCl2(dpa)}2] was isolated. Repeating the latter reaction with (n-Bu4N)[ReOCl4] as starting material in ethanol at room temperature a dark green product, also with the formulation (μ-O)[{ReOCl2(dpa)}2], was isolated. The reaction of equimolar quantities of bis(pyridin-2-yl)methyl)amine (HBPA) with (n-Bu4N)[ReOCl4] in acetone at room temperature led to the isolation of the sixcoordinate rhenium(V) complex [ReOCl(H2O)(BPA)]Cl. IR, NMR and X-ray crystallographic results indicate that BPA is coordinated as a tridentate uninegative chelate, with deprotonation of the amine nitrogen. The water molecule is coordinated trans to the oxo group, with the Re=O and Re-OH2 bond distances equal to 1.663(9) and 2.21(1) Å respectively. Complexes of the general formula [ReOX2{(C5H4N)CH(O)CH2(C5H4N)}] (X = Cl, I) were prepared by the reactions of trans-[ReOCl3(PPh3)2] and trans- [ReOI2(OEt)(PPh3)2] with cis-1,2-di-(2-pyridyl)ethylene (DPE) in ethanol and benzene in air. Experimental evidence shows that the coordinated DPE ligand has undergone addition of water at the ethylenic carbons, and that the (C5H4N)CH(O)CH2(C5H4N) moiety acts as a uninegative tridentate NON-donor ligand. The X-ray crystal structures of both complexes show a distorted octahedral geometry around the rhenium(V) centre. The treatment of trans-[ReOCl3(PPh3)2] with H2dbd in a 2:1 molar ratio in acetonitrile led to the isolation of the ligand-bridged dimer (μ-dbd)[ReOCl2(PPh3)]2. The X-ray crystal structure of the complex reveals a dinuclear structure in which two rhenium(V) ions are bridged by the dbd ligand. Each rhenium ion is in a x A. Abrahams Nelson Mandela Metropolitan University distorted octahedral geometry. The basal plane is defined by a phosphorus atom of the PPh3 group, two chlorides cis to each other, and a pyridyl nitrogen atom of dbd. The oxo group and alcoholate oxygen of dbd lie in trans axial positions. The complexes cis-[ReOX2(msa)(PPh3)] (X = Cl, Br, I) were prepared from trans- [ReOCl3(PPh3)2], trans-[ReOBr3(PPh3)2] or trans-[ReOI2(OEt)(PPh3)2] with 2-(1- iminoethyl)phenol (Hmsa) in acetonitrile. An X-ray crystallographic study shows that the bonding distances and angles in the comlexes are nearly identical, and that the two halides in each complex are coordinated cis to each other in the equatorial plane cis to the oxo group. The oxo-bridged dinuclear rhenium(V) complex [(μ-O){ReOCl(amp)}2] was prepared by the reaction of trans-[ReOCl3(PPh3)2] and 6-amino-3-methyl-1-phenyl- 4-azahept-2-ene-1-one (Hamp) in acetone. The characterization of the complex by elemental analysis, infrared and 1H NMR spectroscopy and X-ray crystallography shows that amp is coordinated as a monoanionic NNO-donor chelate as an amino-amido ketone. However, the reaction of the similar ligand 7- amino-4,7-dimethyl-5-aza-3-octen-2-one (Hada) with [Re(CO)5Br] produced the product fac-[Re(CO)3Br(Hada)], with Hada coordinated as a neutral NN-donor amino-imino-ketone.
- Full Text:
- Date Issued: 2009
The development and evaluation of a programme to promote sensitive pscyhotherapeutic practice with gay men and lesbians
- Authors: Coetzee, Catherine Ann
- Date: 2009
- Subjects: Psychotherapy -- Practice -- South Africa Psychoanalysis and homosexuality -- South Africa Homosexuality -- Social aspects -- South Africa Homosexuality -- Psychological aspects -- South Africa Psychotherapy -- Moral and ethical aspects -- South Africa Psychologists -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2952 , http://hdl.handle.net/10962/d1002461
- Description: Clinical psychology’s relevance and future viability depend on its ability to render services that are relevant and sensitive to multicultural and minority issues. Lesbian, gay, bisexual and transgendered people are one such group that professional psychology – both in South Africa and abroad - has identified as having unique treatment needs for which psychologists require specialised knowledge and skills in order to render appropriate treatment. Competence to treat non-heterosexual patients has been framed in terms of a gay affirmative paradigm which has as its basic tenet the recognition that same-gender orientation is not pathological but rather a healthy alternative to heterosexuality. From this perspective being “gay friendly” or “gay accepting” is not enough. To implement a gay affirmative approach in practice, practitioners must have resolved their possible prejudice and heterosexist bias and have the requisite knowledge of concerns unique to lesbian, gay, and bisexual (LGB) individuals to be able to apply their skills in a culturally sensitive manner. Although more American post-graduate psychology programmes are addressing sexual diversity, their failure to produce psychologists who feel competent to treat lesbian/gay or bisexual individuals has highlighted the need to develop effective training strategies based on empirical nvestigation. The dearth of comparable data about local South African psychology training prompted this inquiry which had four broad aims namely, (i) to establish to what extent trainees’ prior training had equipped them with the knowledge, awareness, and skills to approach their work with non-heterosexual patients in a gay affirmative manner, and (ii) to implement and (iii) to evaluate to what extent a brief structured training programme is effective in engaging the trainees; in increasing knowledge, in raising awareness, and in changing specific attitudes and imparting specific skills required for treating lesbian and gay patients.; and (iv) what, if any, recommendations should be made for the future with respect to training of sychologists in this area? The field of sexual orientation research has been expanded to include issues pertaining to bisexual, transgendered and intersexed people, but serious time constraints meant that issues pertaining to these groups could not be addressed in depth. Although the exclusion of these groups is problematic and may be seen as reinforcing their invisibility, it was decided to focus primarily on gay and lesbian issues s an introduction to same-sex orientation. It is envisaged that bisexual and transgender issues would be dealt with in depth in more advanced training. Nine trainee psychologists employed at hospitals in the greater Cape Town area volunteered to participate in the programme which comprised a series of two-hour experiential workshops offered once a week over six weeks. The study employed both quantitative and qualitative data analysis methods. The first stage entailed gathering information to better understand trainees’ existing level of competence. Individual interviews were conducted prior to the course to obtain data about their attitudes and perceptions regarding the need for such specialised training, and how qualified they considered themselves to be to treat LGB patients, and their experience in this regard. For the purpose of the over-all analysis information was also gathered about pertinent personal and social characteristics of the trainees, as well as their contact with lesbian/gay persons. In addition, an attitude survey and the Lesbian, Gay, and Bisexual Counselling Self-efficacy Scale (LGB-CSI) were administered to obtain benchmarks against which change could be measured. The second stage involved the implementation of the educational programme and gathering information about trainees’ responses to its various components. This stage concentrated on discovering how individual trainees reacted to material on lesbian, gay, and bisexual issues and how they used the programme to improve their self-awareness and skills. The results indicate that local psychology training might not address same-gender orientation adequately, thus reinforcing trainees’ belief that sexual orientation is irrelevant, and that their generalist training equips them to work with gay/lesbian/bisexual patients. While the training strengthened existing positive attitudes, it was less effective in changing blatant antigay prejudice. However, both quantitative and qualitative data suggest that the programme increased individuals’ awareness and insight into their previously unrecognised heterosexist biases and created greater understanding of the effects of stigmatisation on sexual minority individuals. In addition, the training increased trainee’s sense of competence to provide affirmative treatment as evidenced by the significant differences between the pre- and post-training mean scores on the Relationship, Knowledge, and Advocacy Scales and between the mid- and post-training means scores on the Assessment and Awareness Scales of the LGB-CSI. Despite the limited generalisability of these findings on account of possible sampling bias, the need and value of such training was confirmed by trainees’ recommendation that this programme should be a mandatory offering in the first year of clinical psychology training.
- Full Text:
- Date Issued: 2009
- Authors: Coetzee, Catherine Ann
- Date: 2009
- Subjects: Psychotherapy -- Practice -- South Africa Psychoanalysis and homosexuality -- South Africa Homosexuality -- Social aspects -- South Africa Homosexuality -- Psychological aspects -- South Africa Psychotherapy -- Moral and ethical aspects -- South Africa Psychologists -- Training of -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2952 , http://hdl.handle.net/10962/d1002461
- Description: Clinical psychology’s relevance and future viability depend on its ability to render services that are relevant and sensitive to multicultural and minority issues. Lesbian, gay, bisexual and transgendered people are one such group that professional psychology – both in South Africa and abroad - has identified as having unique treatment needs for which psychologists require specialised knowledge and skills in order to render appropriate treatment. Competence to treat non-heterosexual patients has been framed in terms of a gay affirmative paradigm which has as its basic tenet the recognition that same-gender orientation is not pathological but rather a healthy alternative to heterosexuality. From this perspective being “gay friendly” or “gay accepting” is not enough. To implement a gay affirmative approach in practice, practitioners must have resolved their possible prejudice and heterosexist bias and have the requisite knowledge of concerns unique to lesbian, gay, and bisexual (LGB) individuals to be able to apply their skills in a culturally sensitive manner. Although more American post-graduate psychology programmes are addressing sexual diversity, their failure to produce psychologists who feel competent to treat lesbian/gay or bisexual individuals has highlighted the need to develop effective training strategies based on empirical nvestigation. The dearth of comparable data about local South African psychology training prompted this inquiry which had four broad aims namely, (i) to establish to what extent trainees’ prior training had equipped them with the knowledge, awareness, and skills to approach their work with non-heterosexual patients in a gay affirmative manner, and (ii) to implement and (iii) to evaluate to what extent a brief structured training programme is effective in engaging the trainees; in increasing knowledge, in raising awareness, and in changing specific attitudes and imparting specific skills required for treating lesbian and gay patients.; and (iv) what, if any, recommendations should be made for the future with respect to training of sychologists in this area? The field of sexual orientation research has been expanded to include issues pertaining to bisexual, transgendered and intersexed people, but serious time constraints meant that issues pertaining to these groups could not be addressed in depth. Although the exclusion of these groups is problematic and may be seen as reinforcing their invisibility, it was decided to focus primarily on gay and lesbian issues s an introduction to same-sex orientation. It is envisaged that bisexual and transgender issues would be dealt with in depth in more advanced training. Nine trainee psychologists employed at hospitals in the greater Cape Town area volunteered to participate in the programme which comprised a series of two-hour experiential workshops offered once a week over six weeks. The study employed both quantitative and qualitative data analysis methods. The first stage entailed gathering information to better understand trainees’ existing level of competence. Individual interviews were conducted prior to the course to obtain data about their attitudes and perceptions regarding the need for such specialised training, and how qualified they considered themselves to be to treat LGB patients, and their experience in this regard. For the purpose of the over-all analysis information was also gathered about pertinent personal and social characteristics of the trainees, as well as their contact with lesbian/gay persons. In addition, an attitude survey and the Lesbian, Gay, and Bisexual Counselling Self-efficacy Scale (LGB-CSI) were administered to obtain benchmarks against which change could be measured. The second stage involved the implementation of the educational programme and gathering information about trainees’ responses to its various components. This stage concentrated on discovering how individual trainees reacted to material on lesbian, gay, and bisexual issues and how they used the programme to improve their self-awareness and skills. The results indicate that local psychology training might not address same-gender orientation adequately, thus reinforcing trainees’ belief that sexual orientation is irrelevant, and that their generalist training equips them to work with gay/lesbian/bisexual patients. While the training strengthened existing positive attitudes, it was less effective in changing blatant antigay prejudice. However, both quantitative and qualitative data suggest that the programme increased individuals’ awareness and insight into their previously unrecognised heterosexist biases and created greater understanding of the effects of stigmatisation on sexual minority individuals. In addition, the training increased trainee’s sense of competence to provide affirmative treatment as evidenced by the significant differences between the pre- and post-training mean scores on the Relationship, Knowledge, and Advocacy Scales and between the mid- and post-training means scores on the Assessment and Awareness Scales of the LGB-CSI. Despite the limited generalisability of these findings on account of possible sampling bias, the need and value of such training was confirmed by trainees’ recommendation that this programme should be a mandatory offering in the first year of clinical psychology training.
- Full Text:
- Date Issued: 2009
The development and evaluation of gaze selection techniques
- Authors: Van Tonder, Martin Stephen
- Date: 2009
- Subjects: Human-computer interaction , User interfaces (Computer systems) , Gaze
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10469 , http://hdl.handle.net/10948/882 , Human-computer interaction , User interfaces (Computer systems) , Gaze
- Description: Eye gaze interaction enables users to interact with computers using their eyes. A wide variety of eye gaze interaction techniques have been developed to support this type of interaction. Gaze selection techniques, a class of eye gaze interaction techniques which support target selection, are the subject of this research. Researchers developing these techniques face a number of challenges. The most significant challenge is the limited accuracy of eye tracking equipment (due to the properties of the human eye). The design of gaze selection techniques is dominated by this constraint. Despite decades of research, existing techniques are still significantly less accurate than the mouse. A recently developed technique, EyePoint, represents the state of the art in gaze selection techniques. EyePoint combines gaze input with keyboard input. Evaluation results for this technique are encouraging, but accuracy is still a concern. Early trigger errors, resulting from users triggering a selection before looking at the intended target, were found to be the most commonly occurring errors for this technique. The primary goal of this research was to improve the usability of gaze selection techniques. In order to achieve this goal, novel gaze selection techniques were developed. New techniques were developed by combining elements of existing techniques in novel ways. Seven novel gaze selection techniques were developed. Three of these techniques were selected for evaluation. A software framework was developed for implementing and evaluating gaze selection techniques. This framework was used to implement the gaze selection techniques developed during this research. Implementing and evaluating all of the techniques using a common framework ensured consistency when comparing the techniques. The novel techniques which were developed were evaluated against EyePoint and the mouse using the framework. The three novel techniques evaluated were named TargetPoint, StaggerPoint and ScanPoint. TargetPoint combines motor space expansion with a visual feedback highlight whereas the StaggerPoint and TargetPoint designs explore novel approaches to target selection disambiguation. A usability evaluation of the three novel techniques alongside EyePoint and the mouse revealed some interesting trends. TargetPoint was found to be more usable and accurate than EyePoint. This novel technique also proved more popular with test participants. One aspect of TargetPoint which proved particularly popular was the visual feedback highlight, a feature which was found to be a more effective method of combating early trigger errors than existing approaches. StaggerPoint was more efficient than EyePoint, but was less effective and satisfying. ScanPoint was the least popular technique. The benefits of providing a visual feedback highlight and test participants' positive views thereof contradict views expressed in existing research regarding the usability of visual feedback. These results have implications for the design of future gaze selection techniques. A set of design principles was developed for designing new gaze selection techniques. The designers of gaze selection techniques can benefit from these design principles by applying them to their techniques
- Full Text:
- Date Issued: 2009
- Authors: Van Tonder, Martin Stephen
- Date: 2009
- Subjects: Human-computer interaction , User interfaces (Computer systems) , Gaze
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10469 , http://hdl.handle.net/10948/882 , Human-computer interaction , User interfaces (Computer systems) , Gaze
- Description: Eye gaze interaction enables users to interact with computers using their eyes. A wide variety of eye gaze interaction techniques have been developed to support this type of interaction. Gaze selection techniques, a class of eye gaze interaction techniques which support target selection, are the subject of this research. Researchers developing these techniques face a number of challenges. The most significant challenge is the limited accuracy of eye tracking equipment (due to the properties of the human eye). The design of gaze selection techniques is dominated by this constraint. Despite decades of research, existing techniques are still significantly less accurate than the mouse. A recently developed technique, EyePoint, represents the state of the art in gaze selection techniques. EyePoint combines gaze input with keyboard input. Evaluation results for this technique are encouraging, but accuracy is still a concern. Early trigger errors, resulting from users triggering a selection before looking at the intended target, were found to be the most commonly occurring errors for this technique. The primary goal of this research was to improve the usability of gaze selection techniques. In order to achieve this goal, novel gaze selection techniques were developed. New techniques were developed by combining elements of existing techniques in novel ways. Seven novel gaze selection techniques were developed. Three of these techniques were selected for evaluation. A software framework was developed for implementing and evaluating gaze selection techniques. This framework was used to implement the gaze selection techniques developed during this research. Implementing and evaluating all of the techniques using a common framework ensured consistency when comparing the techniques. The novel techniques which were developed were evaluated against EyePoint and the mouse using the framework. The three novel techniques evaluated were named TargetPoint, StaggerPoint and ScanPoint. TargetPoint combines motor space expansion with a visual feedback highlight whereas the StaggerPoint and TargetPoint designs explore novel approaches to target selection disambiguation. A usability evaluation of the three novel techniques alongside EyePoint and the mouse revealed some interesting trends. TargetPoint was found to be more usable and accurate than EyePoint. This novel technique also proved more popular with test participants. One aspect of TargetPoint which proved particularly popular was the visual feedback highlight, a feature which was found to be a more effective method of combating early trigger errors than existing approaches. StaggerPoint was more efficient than EyePoint, but was less effective and satisfying. ScanPoint was the least popular technique. The benefits of providing a visual feedback highlight and test participants' positive views thereof contradict views expressed in existing research regarding the usability of visual feedback. These results have implications for the design of future gaze selection techniques. A set of design principles was developed for designing new gaze selection techniques. The designers of gaze selection techniques can benefit from these design principles by applying them to their techniques
- Full Text:
- Date Issued: 2009
The ecophysiology of Gelidium Pristoides (Turner) Kuetzing : towards commercial cultivation
- Authors: Steyn, Paul-Pierre
- Date: 2009
- Subjects: Marine algae -- South Africa , Marine algae -- Ecophysiology , Red algae -- South Africa , Gelidium -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10617 , http://hdl.handle.net/10948/1117 , Marine algae -- South Africa , Marine algae -- Ecophysiology , Red algae -- South Africa , Gelidium -- South Africa
- Description: The ecophysiology of the red alga Gelidium pristoides (Turner) Kuetzing was investigated in an effort to establish a technique for commercial cultivation. The seaweed is of commercial importance in South Africa where it is harvested from the intertidal zone rocky shores along the coast. It is dried and exported abroad for the extraction of agar. Yields and quality could be improved by cultivation in commercial systems. However, attempts at growing the seaweed in experimental systems have all ended in failure. This study aimed to describe the conditions in which the seaweed grows naturally; and investigate its physiological response to selected physical conditions in the laboratory in order to determine suitable conditions for mariculture. Ecological studies showed that G. pristoides grew above the spring low tide water level. The upper limit of the seaweed’s vertical distribution range, as well as its abundance, was largely dependent on wave exposure. The zone normally inhabited by G. pristoides was dominated by coralline turf in sheltered areas, while the abundance of G. pristoides increased towards more exposed rocky shore sites. The seaweed occurred among species such as Pattelid limpets and barnacles, but was usually the dominant macroalga in this zone, with coralline turf and encrusting algae being the only others. Physical conditions in the part of the intertidal zone inhabited by G. pristoides were highly variable. During low tide temperatures could vary by as much as 10°C within the three hours between tidal inundation of the seaweed population, while salinity varied by up to 9 ppt, and light intensity by as much as 800 μmol m-2 s-1. During these exposure periods the seaweed suffered up to 20% moisture loss. Laboratory experiments on the seaweed’s response to these conditions indicated that it was well adapted to such fluctuations. It had a broad salinity (20 and 40 ppt), and temperature tolerance range (18 to 24°C), with an o ptimum of temperature of 21°C for photosynthesis, while there was no difference in the photosynthetic rate of the alga within the 20 to 40 ppt salinity range. The alga had a low saturating irradiance (ca. 45 – 80 μmol m-2 s-1) equipping it well for photosynthesis in turbulent environments, with high light attenuation, but poorly to unattenuated light conditions. Exposure resulted in an initial increase in photosynthetic rate followed by a gradual decrease thereafter. pH drift experiments showed that low seawater pH, and associated increased carbon dioxide availability, resulted in an increase in photosynthetic rate. This response suggests that the seaweed has a high affinity for carbon dioxide, while the reduction in photosynthetic rate in response to bicarbonate use inhibition indicates that it also has the capacity for bicarbonate use. The high affinity of Gelidium pristoides for carbon dioxide as an inorganic carbon source appears to be the primary reason for the low abundance of the alga on sheltered rocky shore areas, and also explains the failure of the alga to grow in tank or open-water mariculture systems. Exposed rocky shores have experience heavy wave action, and the resultant aeration and mixing of nearshore waters increases the availability of carbon dioxide, which is considered a limiting resource. The absence of such mixing and aeration at sheltered site makes this less suitable habitat for G. pristoides. Periodic exposure also makes high levels of atmospheric carbon dioxide available from which the seaweed benefits. The traditional mariculture systems in which attempts have been made to cultivate the seaweed failed to satisfy either of the above conditions.
- Full Text:
- Date Issued: 2009
- Authors: Steyn, Paul-Pierre
- Date: 2009
- Subjects: Marine algae -- South Africa , Marine algae -- Ecophysiology , Red algae -- South Africa , Gelidium -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10617 , http://hdl.handle.net/10948/1117 , Marine algae -- South Africa , Marine algae -- Ecophysiology , Red algae -- South Africa , Gelidium -- South Africa
- Description: The ecophysiology of the red alga Gelidium pristoides (Turner) Kuetzing was investigated in an effort to establish a technique for commercial cultivation. The seaweed is of commercial importance in South Africa where it is harvested from the intertidal zone rocky shores along the coast. It is dried and exported abroad for the extraction of agar. Yields and quality could be improved by cultivation in commercial systems. However, attempts at growing the seaweed in experimental systems have all ended in failure. This study aimed to describe the conditions in which the seaweed grows naturally; and investigate its physiological response to selected physical conditions in the laboratory in order to determine suitable conditions for mariculture. Ecological studies showed that G. pristoides grew above the spring low tide water level. The upper limit of the seaweed’s vertical distribution range, as well as its abundance, was largely dependent on wave exposure. The zone normally inhabited by G. pristoides was dominated by coralline turf in sheltered areas, while the abundance of G. pristoides increased towards more exposed rocky shore sites. The seaweed occurred among species such as Pattelid limpets and barnacles, but was usually the dominant macroalga in this zone, with coralline turf and encrusting algae being the only others. Physical conditions in the part of the intertidal zone inhabited by G. pristoides were highly variable. During low tide temperatures could vary by as much as 10°C within the three hours between tidal inundation of the seaweed population, while salinity varied by up to 9 ppt, and light intensity by as much as 800 μmol m-2 s-1. During these exposure periods the seaweed suffered up to 20% moisture loss. Laboratory experiments on the seaweed’s response to these conditions indicated that it was well adapted to such fluctuations. It had a broad salinity (20 and 40 ppt), and temperature tolerance range (18 to 24°C), with an o ptimum of temperature of 21°C for photosynthesis, while there was no difference in the photosynthetic rate of the alga within the 20 to 40 ppt salinity range. The alga had a low saturating irradiance (ca. 45 – 80 μmol m-2 s-1) equipping it well for photosynthesis in turbulent environments, with high light attenuation, but poorly to unattenuated light conditions. Exposure resulted in an initial increase in photosynthetic rate followed by a gradual decrease thereafter. pH drift experiments showed that low seawater pH, and associated increased carbon dioxide availability, resulted in an increase in photosynthetic rate. This response suggests that the seaweed has a high affinity for carbon dioxide, while the reduction in photosynthetic rate in response to bicarbonate use inhibition indicates that it also has the capacity for bicarbonate use. The high affinity of Gelidium pristoides for carbon dioxide as an inorganic carbon source appears to be the primary reason for the low abundance of the alga on sheltered rocky shore areas, and also explains the failure of the alga to grow in tank or open-water mariculture systems. Exposed rocky shores have experience heavy wave action, and the resultant aeration and mixing of nearshore waters increases the availability of carbon dioxide, which is considered a limiting resource. The absence of such mixing and aeration at sheltered site makes this less suitable habitat for G. pristoides. Periodic exposure also makes high levels of atmospheric carbon dioxide available from which the seaweed benefits. The traditional mariculture systems in which attempts have been made to cultivate the seaweed failed to satisfy either of the above conditions.
- Full Text:
- Date Issued: 2009
The impact of HIV and AIDS on household food security and food acquisition strategies in South Africa
- Authors: Kaschula, S A H
- Date: 2009
- Subjects: Food security -- South Africa Food supply -- South Africa AIDS (Disease) -- Social aspects -- South Africa HIV infections -- Social aspects -- South Africa Chronically ill -- Economic conditions -- South Africa Chronically ill -- Social conditions -- South Africa Food -- Social aspects -- South Africa Food -- Economic aspects -- South Africa Rural development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4754 , http://hdl.handle.net/10962/d1007137
- Description: How should the impact of HIV and AIDS on rural livelihoods be factored into efforts to monitor and stabilise household food security? With both HIV and AIDS and food security at the top of the global development agenda, this is a question posed by many scholars, practitioners, donor agencies and government departments. However, while there is an excess of discourse outlining the theoretical bases for how HIV and AIDS can, and is, radically transforming household food acquisition; there is a lack of empirical evidence from the South African context that demonstrates if, and how, HIV and AIDS changes household-level strategies of food acquisition and intake. This thesis explores the association of household-level mortality, chronic illness and additional child-dependent fostering with household experience of food security and food acquisition strategies, in three rural villages in the Eastern Cape and KwaZulu-Natal Provinces of South Africa. Qualitative and quantitative methods of data-collection were applied to 307 households in the three sites. For twelve months, both HIV and AIDS-afflicted and non-afflicted households were repeatedly visited at 3-month intervals, in order to be assessed for levels of food security, dietary intake and method of food procurement (purchased, cultivated, wild or donated). Overall, HIV and AIDS-afflicted households showed a significantly higher experience of food insecurity, probably attributable to shortages in food quantity. Dietary composition and overall diversity, however, was not significantly different. Although households with chronic illness and recent mortality showed a heightened investment in cultivation sources, the success of these strategies were to a great extent mediated by household income, and the level of medical treatment received by those who were chronically ill. Chronic illness was also associated with more donations, but these required considerable investments in social capital networks. Finally, use of wild leafy vegetables was not associated with household HIV and AIDS status, despite the financial, nutritional and labour-saving properties of these foods. Overall, the study suggests that there was little evidence of long-term planning and strategy in household food security responses. There was no evidence for shifts to labour-saving crops or foods and, in some instances, child labour was being used to ameliorate prime-adult labour deficits. Moreover, given that the vast majority (89.2%) of food groups were sourced through purchase, it is questionable whether investing in diverse food acquisition strategies would be advisable. Unless supported by medical treatment and steady earned household income, policies to promote intensified household agricultural subsistence production in the wake of HIV and AIDS are unlikely to provide households with anything more than short-term safety-nets, rather than long-term, sustainable food security solutions.
- Full Text:
- Date Issued: 2009
- Authors: Kaschula, S A H
- Date: 2009
- Subjects: Food security -- South Africa Food supply -- South Africa AIDS (Disease) -- Social aspects -- South Africa HIV infections -- Social aspects -- South Africa Chronically ill -- Economic conditions -- South Africa Chronically ill -- Social conditions -- South Africa Food -- Social aspects -- South Africa Food -- Economic aspects -- South Africa Rural development -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:4754 , http://hdl.handle.net/10962/d1007137
- Description: How should the impact of HIV and AIDS on rural livelihoods be factored into efforts to monitor and stabilise household food security? With both HIV and AIDS and food security at the top of the global development agenda, this is a question posed by many scholars, practitioners, donor agencies and government departments. However, while there is an excess of discourse outlining the theoretical bases for how HIV and AIDS can, and is, radically transforming household food acquisition; there is a lack of empirical evidence from the South African context that demonstrates if, and how, HIV and AIDS changes household-level strategies of food acquisition and intake. This thesis explores the association of household-level mortality, chronic illness and additional child-dependent fostering with household experience of food security and food acquisition strategies, in three rural villages in the Eastern Cape and KwaZulu-Natal Provinces of South Africa. Qualitative and quantitative methods of data-collection were applied to 307 households in the three sites. For twelve months, both HIV and AIDS-afflicted and non-afflicted households were repeatedly visited at 3-month intervals, in order to be assessed for levels of food security, dietary intake and method of food procurement (purchased, cultivated, wild or donated). Overall, HIV and AIDS-afflicted households showed a significantly higher experience of food insecurity, probably attributable to shortages in food quantity. Dietary composition and overall diversity, however, was not significantly different. Although households with chronic illness and recent mortality showed a heightened investment in cultivation sources, the success of these strategies were to a great extent mediated by household income, and the level of medical treatment received by those who were chronically ill. Chronic illness was also associated with more donations, but these required considerable investments in social capital networks. Finally, use of wild leafy vegetables was not associated with household HIV and AIDS status, despite the financial, nutritional and labour-saving properties of these foods. Overall, the study suggests that there was little evidence of long-term planning and strategy in household food security responses. There was no evidence for shifts to labour-saving crops or foods and, in some instances, child labour was being used to ameliorate prime-adult labour deficits. Moreover, given that the vast majority (89.2%) of food groups were sourced through purchase, it is questionable whether investing in diverse food acquisition strategies would be advisable. Unless supported by medical treatment and steady earned household income, policies to promote intensified household agricultural subsistence production in the wake of HIV and AIDS are unlikely to provide households with anything more than short-term safety-nets, rather than long-term, sustainable food security solutions.
- Full Text:
- Date Issued: 2009
The invasion of pteronia incana (blue bush) along a range of gradients in the Eastern Cape Province : it's spectral chacteristics and implications for soil moisture
- Authors: Odindi, John Odhiambo
- Date: 2009
- Subjects: Invasive plants -- South Africa -- Eastern Cape , Alien plants -- South Africa -- Eastern Cape , Soil moisture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10650 , http://hdl.handle.net/10948/1052 , Invasive plants -- South Africa -- Eastern Cape , Alien plants -- South Africa -- Eastern Cape , Soil moisture -- South Africa -- Eastern Cape
- Description: Extensive areas of the Eastern Cape Province have been invaded by Pteronia incana (Blue bush), a non-palatable patchy invader shrub that is associated with soil degradation. This study sought to establish the relationship between the invasion and a range of eco-physical and land use gradients. The impact of the invader on soil moisture flux was investigated by comparing soil moisture variations under grass, bare and P. incana invaded surfaces. Field based and laboratory spectroscopy was used to validate P. incana spectral characteristics identified from multi-temporal High Resolution Imagery (HRI). A belt transect was surveyed to gain an understanding of the occurrence of the invasion across land use, isohyetic, geologic, vegetation, pedologic and altitudinal gradients. Soil moisture sensors were calibrated and installed under the respective surfaces in order to determine soil moisture trends over a period of six months. To classify the surfaces using HRI, the pixel and sub-pixel based Perpendicular Vegetation Index (PVI) and Spectral Mixture Analysis (SMA) respectively were used. There was no clear trend established between the underlying geology and P. incana invasion. Land disturbance in general was strongly associated with the invasion, as the endemic zone for the invasion mainly comprised abandoned cultivated and overgrazed land. Isohyetic gradients emerged as the major limiting factor of the invasion; a distinct zone below 619mm of mean annual rainfall was identified as the apparent boundary for the invasion. Low organic matter content identified under invaded areas was attributed to the patchy nature of the invader, leading to loss of the top soil in the bare inter-patch areas. The area covered by grass had consistently higher moisture values than P. incana and bare surfaces. The difference in post-rainfall moisture retention between grass and P. incana surfaces was significant up to about six days, after which a near parallel trend was noticed towards the ensuing rainfall episode. Whereas a higher amount of moisture was recorded on grass, the surface experienced moisture loss faster than the invaded and bare surfaces after each rainfall episode. ii There was consistency in multi-temporal Digital Number (DN) values for the surfaces investigated. The typically low P. incana reflectance in the Near Infrared band, identified from the multi-temporal HRI was validated by field and laboratory spectroscopy. The PVI showed clear spectral separability between all the land surfaces in the respective multi-temporal HRI. The consistence of the PVI with the unmixed surface image fractions from the SMA illustrates that using HRI, the effectiveness of the PVI is not impeded by the mixed pixel problem. Results of the laboratory spectroscopy that validated HRI analyses showed that P. incana’s typically low reflectance is a function of its leaf canopy, as higher proportions of leaves gave a higher reflectance. Future research directions could focus on comparisons between P. incana and typical green vegetation internal leaf structures as potential causes of spectral differences. Collection of spectra for P incana and other invader vegetation types, some of which have similar characteristics, with a view to assembling a spectral library for delineating invaded environments using imagery, is another research direction.
- Full Text:
- Date Issued: 2009
- Authors: Odindi, John Odhiambo
- Date: 2009
- Subjects: Invasive plants -- South Africa -- Eastern Cape , Alien plants -- South Africa -- Eastern Cape , Soil moisture -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:10650 , http://hdl.handle.net/10948/1052 , Invasive plants -- South Africa -- Eastern Cape , Alien plants -- South Africa -- Eastern Cape , Soil moisture -- South Africa -- Eastern Cape
- Description: Extensive areas of the Eastern Cape Province have been invaded by Pteronia incana (Blue bush), a non-palatable patchy invader shrub that is associated with soil degradation. This study sought to establish the relationship between the invasion and a range of eco-physical and land use gradients. The impact of the invader on soil moisture flux was investigated by comparing soil moisture variations under grass, bare and P. incana invaded surfaces. Field based and laboratory spectroscopy was used to validate P. incana spectral characteristics identified from multi-temporal High Resolution Imagery (HRI). A belt transect was surveyed to gain an understanding of the occurrence of the invasion across land use, isohyetic, geologic, vegetation, pedologic and altitudinal gradients. Soil moisture sensors were calibrated and installed under the respective surfaces in order to determine soil moisture trends over a period of six months. To classify the surfaces using HRI, the pixel and sub-pixel based Perpendicular Vegetation Index (PVI) and Spectral Mixture Analysis (SMA) respectively were used. There was no clear trend established between the underlying geology and P. incana invasion. Land disturbance in general was strongly associated with the invasion, as the endemic zone for the invasion mainly comprised abandoned cultivated and overgrazed land. Isohyetic gradients emerged as the major limiting factor of the invasion; a distinct zone below 619mm of mean annual rainfall was identified as the apparent boundary for the invasion. Low organic matter content identified under invaded areas was attributed to the patchy nature of the invader, leading to loss of the top soil in the bare inter-patch areas. The area covered by grass had consistently higher moisture values than P. incana and bare surfaces. The difference in post-rainfall moisture retention between grass and P. incana surfaces was significant up to about six days, after which a near parallel trend was noticed towards the ensuing rainfall episode. Whereas a higher amount of moisture was recorded on grass, the surface experienced moisture loss faster than the invaded and bare surfaces after each rainfall episode. ii There was consistency in multi-temporal Digital Number (DN) values for the surfaces investigated. The typically low P. incana reflectance in the Near Infrared band, identified from the multi-temporal HRI was validated by field and laboratory spectroscopy. The PVI showed clear spectral separability between all the land surfaces in the respective multi-temporal HRI. The consistence of the PVI with the unmixed surface image fractions from the SMA illustrates that using HRI, the effectiveness of the PVI is not impeded by the mixed pixel problem. Results of the laboratory spectroscopy that validated HRI analyses showed that P. incana’s typically low reflectance is a function of its leaf canopy, as higher proportions of leaves gave a higher reflectance. Future research directions could focus on comparisons between P. incana and typical green vegetation internal leaf structures as potential causes of spectral differences. Collection of spectra for P incana and other invader vegetation types, some of which have similar characteristics, with a view to assembling a spectral library for delineating invaded environments using imagery, is another research direction.
- Full Text:
- Date Issued: 2009
The South African community pharmacist and Type 2 Diabetes Mellitus a pharmaceutical care intervention
- Authors: Hill, Peter William
- Date: 2009
- Subjects: Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3760 , http://hdl.handle.net/10962/d1003238 , Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Description: Type 2 diabetes mellitus is a chronic disease of pandemic magnitude, increasingly contributing to the disease burden of countries in the developing world, largely because of the effects of unhealthy lifestyles fuelled by unbridled urbanisation. In certain settings, patients with diabetes are more likely to have a healthcare encounter with a pharmacist than with any other healthcare provider. The overall aim of the study was to investigate the potential of South African community pharmacists to positively influence patient adherence and metabolic control in Type 2 diabetes. The designated primary endpoint was glycated haemoglobin, with the intermediate health outcomes of blood lipids, serum creatinine, blood pressure and body mass index serving as secondary endpoints. Community pharmacists and their associated Type 2 diabetes patients were recruited from areas throughout South Africa using the communication media of various nonstatutory pharmacy organisations. Although 156 pharmacists initially indicated interest in participating in the study, only 28 pharmacists and 153 patients were enrolled prior to baseline data collection. Of these, 16 pharmacists and 57 patients participated in the study for the full twelve months. Baseline clinical and psychosocial data were collected, after which pharmacists and their patients were randomised, nine pharmacists and 34 patients to the intervention group and 8 pharmacists and 27 patients to the control group. The sample size calculation revealed that each group required the participation of a minimum of 35 patients. Control pharmacists were requested to offer standard pharmaceutical care, while the intervention pharmacists were provided with a scope of practice diabetes care plan to guide the diabetes care they were to provide. Data were again collected 12-months postbaseline. At baseline, proportionally more intervention patients (82.4%) than control patients (59.3%) were using only oral anti-diabetes agents (i.e. not in combination with insulin), while insulin usage, either alone or in combination with oral agents was conversely greater in the control group (40.7%) than in the intervention group (17.6%) (Chi-squared test, p=0.013). Approximately half of the patients (53.8% control and 47.1% intervention) reported having their HbA1c levels measured in terms of accepted guidelines. There was no significant difference in HbA1c between the groups at the end of the study (Independent t-test, p=0.514). In the control group, the mean HbA1c increased from 7.3±1.2% to 7.6±1.5%, while for the intervention patients the variable remained almost constant (8.2±2.0% at baseline and 8.2±1.8% at post-baseline). Similarly, there were no significant differences between the groups with regard to any of the designated secondary clinical endpoints. Adherence to medication and self-management recommendations was similarly good for both groups. There were no significant differences between the two groups for any of the other psychosocial variables measured. In conclusion, intervention pharmacists were not able to significantly influence glycaemic control or therapeutic adherence compared to the control pharmacists.
- Full Text:
- Date Issued: 2009
- Authors: Hill, Peter William
- Date: 2009
- Subjects: Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:3760 , http://hdl.handle.net/10962/d1003238 , Pharmacist and patient -- South Africa , Pharmaceutical services -- Patients , Pharmaceutical services -- South Africa , Pharmacists -- South Africa , Diabetes -- Treatment -- South Africa , Community health services -- South Africa
- Description: Type 2 diabetes mellitus is a chronic disease of pandemic magnitude, increasingly contributing to the disease burden of countries in the developing world, largely because of the effects of unhealthy lifestyles fuelled by unbridled urbanisation. In certain settings, patients with diabetes are more likely to have a healthcare encounter with a pharmacist than with any other healthcare provider. The overall aim of the study was to investigate the potential of South African community pharmacists to positively influence patient adherence and metabolic control in Type 2 diabetes. The designated primary endpoint was glycated haemoglobin, with the intermediate health outcomes of blood lipids, serum creatinine, blood pressure and body mass index serving as secondary endpoints. Community pharmacists and their associated Type 2 diabetes patients were recruited from areas throughout South Africa using the communication media of various nonstatutory pharmacy organisations. Although 156 pharmacists initially indicated interest in participating in the study, only 28 pharmacists and 153 patients were enrolled prior to baseline data collection. Of these, 16 pharmacists and 57 patients participated in the study for the full twelve months. Baseline clinical and psychosocial data were collected, after which pharmacists and their patients were randomised, nine pharmacists and 34 patients to the intervention group and 8 pharmacists and 27 patients to the control group. The sample size calculation revealed that each group required the participation of a minimum of 35 patients. Control pharmacists were requested to offer standard pharmaceutical care, while the intervention pharmacists were provided with a scope of practice diabetes care plan to guide the diabetes care they were to provide. Data were again collected 12-months postbaseline. At baseline, proportionally more intervention patients (82.4%) than control patients (59.3%) were using only oral anti-diabetes agents (i.e. not in combination with insulin), while insulin usage, either alone or in combination with oral agents was conversely greater in the control group (40.7%) than in the intervention group (17.6%) (Chi-squared test, p=0.013). Approximately half of the patients (53.8% control and 47.1% intervention) reported having their HbA1c levels measured in terms of accepted guidelines. There was no significant difference in HbA1c between the groups at the end of the study (Independent t-test, p=0.514). In the control group, the mean HbA1c increased from 7.3±1.2% to 7.6±1.5%, while for the intervention patients the variable remained almost constant (8.2±2.0% at baseline and 8.2±1.8% at post-baseline). Similarly, there were no significant differences between the groups with regard to any of the designated secondary clinical endpoints. Adherence to medication and self-management recommendations was similarly good for both groups. There were no significant differences between the two groups for any of the other psychosocial variables measured. In conclusion, intervention pharmacists were not able to significantly influence glycaemic control or therapeutic adherence compared to the control pharmacists.
- Full Text:
- Date Issued: 2009