Study of the photophysical behavior of tetrasulfonated metallophthalocyanines in the presence of CdTe quantum dots
- Idowu, Mopelola, Nyokong, Tebello
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264138 , vital:53701 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: Förster resonance energy transfer (FRET) studies were carried out with CdTe quantum dots (QDs) synthesized in aqueous phase and various tetrasulfonated metallophthalocyanines (MPcS4, M = aluminum ((OH)AlPcS4), zinc (ZnPcS4), silicon ((OH)2SiPcS4) and germanium ((OH)2GePcS4) in a H2O:MeOH (1:1) solvent mixture. The QDs studied were capped with thioglycolic acid (TGA) or mercaptopropionic acid (MPA) with sizes ranging from 2.3 to 3.7 nm. Non-radiative energy transfer from QDs emission to MPcS4 complexes was observed. Study of the photophysics of the MPcs in the presence of the QDs revealed high triplet state quantum yields (ΦT, ranging from 0.41 to 0.85 in the presence of QDs), with corresponding long triplet state lifetimes (τT, which ranged from 140 to 610 μs in the presence of QDs) to allow for photosensitized reactions to occur. The efficiency of energy transfer and the donor–acceptor distance between the MPcs and the QDs were also evaluated.
- Full Text:
- Date Issued: 2009
- Authors: Idowu, Mopelola , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/264138 , vital:53701 , xlink:href="https://doi.org/10.1016/j.molstruc.2015.02.040"
- Description: Förster resonance energy transfer (FRET) studies were carried out with CdTe quantum dots (QDs) synthesized in aqueous phase and various tetrasulfonated metallophthalocyanines (MPcS4, M = aluminum ((OH)AlPcS4), zinc (ZnPcS4), silicon ((OH)2SiPcS4) and germanium ((OH)2GePcS4) in a H2O:MeOH (1:1) solvent mixture. The QDs studied were capped with thioglycolic acid (TGA) or mercaptopropionic acid (MPA) with sizes ranging from 2.3 to 3.7 nm. Non-radiative energy transfer from QDs emission to MPcS4 complexes was observed. Study of the photophysics of the MPcs in the presence of the QDs revealed high triplet state quantum yields (ΦT, ranging from 0.41 to 0.85 in the presence of QDs), with corresponding long triplet state lifetimes (τT, which ranged from 140 to 610 μs in the presence of QDs) to allow for photosensitized reactions to occur. The efficiency of energy transfer and the donor–acceptor distance between the MPcs and the QDs were also evaluated.
- Full Text:
- Date Issued: 2009
Peacekeeping in Africa: problems and prospects
- Authors: Juma, Laurence
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/129113 , vital:36219 , https://heinonline.org/HOL/P?h=hein.journals/unbotslj9amp;i=3
- Description: Against the background of an expanded need for peacekeeping, the complexity that its programmes entail, and the belief that it will endure for a long time to come, this article discusses the propriety of international peacekeeping operations, its inherent features and weaknesses in creating or preserving peace, and the role that regional organisations play, or should play, in its enhancement.
- Full Text: false
- Date Issued: 2009
- Authors: Juma, Laurence
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/129113 , vital:36219 , https://heinonline.org/HOL/P?h=hein.journals/unbotslj9amp;i=3
- Description: Against the background of an expanded need for peacekeeping, the complexity that its programmes entail, and the belief that it will endure for a long time to come, this article discusses the propriety of international peacekeeping operations, its inherent features and weaknesses in creating or preserving peace, and the role that regional organisations play, or should play, in its enhancement.
- Full Text: false
- Date Issued: 2009
An intercultural approach to implementing multilingualism at Rhodes University, South Africa
- Kaschula, Russell H, Maseko, Pamela, Dalvit, Lorenzo, Mapi, Thandeka, Nelani, Linda, Nosilela, Bulelwa, Sam, Msindisi S
- Authors: Kaschula, Russell H , Maseko, Pamela , Dalvit, Lorenzo , Mapi, Thandeka , Nelani, Linda , Nosilela, Bulelwa , Sam, Msindisi S
- Date: 2009
- Subjects: Multilingualism -- South Africa , Intercultural communication , Education, Higher -- South Africa , Language and culture -- South Africa , Language and education -- South Africa , Rhodes University
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59390 , vital:27579 , doi: 10.5842/39-0-74
- Description: The work of intercultural communication theorists such as Ting-Toomey (1999) and Gudykunst (2003) has informed curriculum design and teaching methodology of the courses developed for teaching isiXhosa for vocational purposes to second language (L2) learners. This seems to be an appropriate theoretical paradigm within multilingual South Africa, where intercultural communication is becoming a daily reality for a growing portion of the population. We make use of this theory to introduce and develop experiential understanding of multilingualism at Rhodes University in various departments and, more generally, on campus.
- Full Text:
- Date Issued: 2009
- Authors: Kaschula, Russell H , Maseko, Pamela , Dalvit, Lorenzo , Mapi, Thandeka , Nelani, Linda , Nosilela, Bulelwa , Sam, Msindisi S
- Date: 2009
- Subjects: Multilingualism -- South Africa , Intercultural communication , Education, Higher -- South Africa , Language and culture -- South Africa , Language and education -- South Africa , Rhodes University
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59390 , vital:27579 , doi: 10.5842/39-0-74
- Description: The work of intercultural communication theorists such as Ting-Toomey (1999) and Gudykunst (2003) has informed curriculum design and teaching methodology of the courses developed for teaching isiXhosa for vocational purposes to second language (L2) learners. This seems to be an appropriate theoretical paradigm within multilingual South Africa, where intercultural communication is becoming a daily reality for a growing portion of the population. We make use of this theory to introduce and develop experiential understanding of multilingualism at Rhodes University in various departments and, more generally, on campus.
- Full Text:
- Date Issued: 2009
The influence of cellular phone "speak" on isiXhosa rules of communication
- Kaschula, Russell H, Mostert, André
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2009
- Subjects: Cell phones -- South Africa , Communication and culture -- Technological innovations , Language and culture -- South Africa , Xhosa (African people) -- Social life and customs
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59401 , vital:27594 , doi: 10.5842/37-0-43
- Description: Cellular telephones have revolutionised the art of communication across all societies, and South Africa is no exception. Access to this form of communication has made personal contact easier, in both rural and urban contexts. Globally this form of communication has been readily embraced. However, cultural rules that pertain to face-to-face communication are often flouted by cellular phone users. This flouting holds true no doubt across many cultures, languages and contexts. Bloomer (2005:97-100) assesses this flouting of cultural maxims in relation to Grice's cooperative principle. This article attempts to assess how general rules of politeness in isiXhosa have been and are being transformed by what could be termed the "economics of speaking".
- Full Text:
- Date Issued: 2009
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2009
- Subjects: Cell phones -- South Africa , Communication and culture -- Technological innovations , Language and culture -- South Africa , Xhosa (African people) -- Social life and customs
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59401 , vital:27594 , doi: 10.5842/37-0-43
- Description: Cellular telephones have revolutionised the art of communication across all societies, and South Africa is no exception. Access to this form of communication has made personal contact easier, in both rural and urban contexts. Globally this form of communication has been readily embraced. However, cultural rules that pertain to face-to-face communication are often flouted by cellular phone users. This flouting holds true no doubt across many cultures, languages and contexts. Bloomer (2005:97-100) assesses this flouting of cultural maxims in relation to Grice's cooperative principle. This article attempts to assess how general rules of politeness in isiXhosa have been and are being transformed by what could be termed the "economics of speaking".
- Full Text:
- Date Issued: 2009
Analyzing, digitizing and technologizing the oral word: the case of Bongani Sitole
- Kaschula, Russell H, Mostert, André
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2009
- Subjects: Sitole, Bongani, 1937- , Xhosa (African people) -- South Africa , Xhosa poetry , Folk poetry, Xhosa
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59368 , vital:27566 , https://doi.org/10.1080/13696810903259384
- Description: This article analyzes the oral poetry, izibongo, produced by Xhosa oral poet Bongani Sitole (both in book and technological form). It will trace this poetry from the moment it was orally produced, through to the technologizing and publication of this poetry in book form and on a website. The initial part of this article looks at the life and work of the poet. A contextual analysis of selected poetry is provided. The latter part of the article concentrates on issues related to technology and its relationship to the oral and written word. The term ‘technauriture’ has been coined in order to refer to this process. The contribution of eLearning4Africa (www.elearning4africa.com) to the digitization process of Sitole’s poetry is acknowledged.
- Full Text:
- Date Issued: 2009
- Authors: Kaschula, Russell H , Mostert, André
- Date: 2009
- Subjects: Sitole, Bongani, 1937- , Xhosa (African people) -- South Africa , Xhosa poetry , Folk poetry, Xhosa
- Language: English
- Type: article , text
- Identifier: http://hdl.handle.net/10962/59368 , vital:27566 , https://doi.org/10.1080/13696810903259384
- Description: This article analyzes the oral poetry, izibongo, produced by Xhosa oral poet Bongani Sitole (both in book and technological form). It will trace this poetry from the moment it was orally produced, through to the technologizing and publication of this poetry in book form and on a website. The initial part of this article looks at the life and work of the poet. A contextual analysis of selected poetry is provided. The latter part of the article concentrates on issues related to technology and its relationship to the oral and written word. The term ‘technauriture’ has been coined in order to refer to this process. The contribution of eLearning4Africa (www.elearning4africa.com) to the digitization process of Sitole’s poetry is acknowledged.
- Full Text:
- Date Issued: 2009
Between a rock and a hard place:
- Authors: Keeton, Gavin
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159401 , vital:40294 , https://hdl.handle.net/10520/EJC139947
- Description: Gavin Keeton takes an economist's tour of the current crisis : how did it happen and what does it mean?
- Full Text:
- Date Issued: 2009
- Authors: Keeton, Gavin
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/159401 , vital:40294 , https://hdl.handle.net/10520/EJC139947
- Description: Gavin Keeton takes an economist's tour of the current crisis : how did it happen and what does it mean?
- Full Text:
- Date Issued: 2009
Characterization of nickel tetrahydroxy phthalocyanine complexes and the electrocatalytic oxidation of 4-chlorophenol
- Khene, Samson M, Lobb, Kevin A, Nyokong, Tebello
- Authors: Khene, Samson M , Lobb, Kevin A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263308 , vital:53616 , xlink:href="https://doi.org/10.1016/j.ica.2009.08.019"
- Description: This work reports on the use of nickel(II) tetrahydroxy (NiPc(OH)4) and (poly-Ni(OH)Pc(OH)4) phthalocyanine complexes as films on ordinary poly graphite electrode (OPGE) for the electrochemical oxidation of 4-chlorophenol (4-CP). The NiPc(OH)4 film was electrotransformed to Ni(OH)Pc(OH)4 film in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridge form. The result showed that the Ni(OH)Pc(OH)4 film on OPGE was more electroactive in terms of increase in current and less catalytic in terms of potential compared to the adsorbed NiPc(OH)4 on OPGE. The reactivity of the two molecules was explained by theoretical calculations. The energies of the frontier orbitals of NiPc(OH)4, Ni(OH)Pc(OH)4 and 4-chlorophenol were calculated using density functional theory (DFT) method. The inter molecular hardness (η) and donor–acceptor hardness (ηDA) of Ni(OH)Pc(OH)4, NiPc(OH)4, Ni(OH)Pc(OH)4/4-chlorophenol and NiPc(OH)4/4-chlorophenol were estimated. The Ni(OH)Pc(OH)4, showed stronger interaction with 4-chlorophenol than NiPc(OH)4. DFT method was also used to model IR and Raman spectrum of H2Pc(OH)4 and NiPc(OH)4.
- Full Text:
- Date Issued: 2009
- Authors: Khene, Samson M , Lobb, Kevin A , Nyokong, Tebello
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263308 , vital:53616 , xlink:href="https://doi.org/10.1016/j.ica.2009.08.019"
- Description: This work reports on the use of nickel(II) tetrahydroxy (NiPc(OH)4) and (poly-Ni(OH)Pc(OH)4) phthalocyanine complexes as films on ordinary poly graphite electrode (OPGE) for the electrochemical oxidation of 4-chlorophenol (4-CP). The NiPc(OH)4 film was electrotransformed to Ni(OH)Pc(OH)4 film in aqueous 0.1 M NaOH solution to the ‘O–Ni–O oxo’ bridge form. The result showed that the Ni(OH)Pc(OH)4 film on OPGE was more electroactive in terms of increase in current and less catalytic in terms of potential compared to the adsorbed NiPc(OH)4 on OPGE. The reactivity of the two molecules was explained by theoretical calculations. The energies of the frontier orbitals of NiPc(OH)4, Ni(OH)Pc(OH)4 and 4-chlorophenol were calculated using density functional theory (DFT) method. The inter molecular hardness (η) and donor–acceptor hardness (ηDA) of Ni(OH)Pc(OH)4, NiPc(OH)4, Ni(OH)Pc(OH)4/4-chlorophenol and NiPc(OH)4/4-chlorophenol were estimated. The Ni(OH)Pc(OH)4, showed stronger interaction with 4-chlorophenol than NiPc(OH)4. DFT method was also used to model IR and Raman spectrum of H2Pc(OH)4 and NiPc(OH)4.
- Full Text:
- Date Issued: 2009
Glumlazi
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229829 , vital:49715 , xlink:href="https://hdl.handle.net/10520/EJC47808"
- Full Text:
- Date Issued: 2009
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229829 , vital:49715 , xlink:href="https://hdl.handle.net/10520/EJC47808"
- Full Text:
- Date Issued: 2009
White Guys Can't Beg
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229796 , vital:49711 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229796 , vital:49711 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
Nine Notes on Lisbon
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229807 , vital:49712 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229807 , vital:49712 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
St. Petersburg
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229818 , vital:49713 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229818 , vital:49713 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
On Moving House
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229785 , vital:49710 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
- Authors: Krueger, Anton
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/229785 , vital:49710 , xlink:href="https://hdl.handle.net/10520/EJC47812"
- Full Text:
- Date Issued: 2009
'Come back when you are 65, Sir': discrimination in respect of access to social assistance for the elderly
- Authors: Krüger, Rósaan
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71119 , vital:29786 , http://www.ldd.org.za/images/stories/Ready_for_publication/V10-2_Come_back_65.pdf
- Description: Messrs Roberts, Whitebooi, Casling and Visagie are four elderly gentlemen who live in poverty in Gelvandale, Port Elizabeth. At the end of 2005 they wished to apply for social assistance from the State. At the time of their applications, the men were over the age of 60, but none of them had attained the age of 65. Had they been female, they would have qualified for social assistance in the form of old age pensions at the age of 60. 'These pensions would not have made them rich, but would have enabled them to sustain themselves.
- Full Text:
- Date Issued: 2009
- Authors: Krüger, Rósaan
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71119 , vital:29786 , http://www.ldd.org.za/images/stories/Ready_for_publication/V10-2_Come_back_65.pdf
- Description: Messrs Roberts, Whitebooi, Casling and Visagie are four elderly gentlemen who live in poverty in Gelvandale, Port Elizabeth. At the end of 2005 they wished to apply for social assistance from the State. At the time of their applications, the men were over the age of 60, but none of them had attained the age of 65. Had they been female, they would have qualified for social assistance in the form of old age pensions at the age of 60. 'These pensions would not have made them rich, but would have enabled them to sustain themselves.
- Full Text:
- Date Issued: 2009
Of fences and peace between neighbours
- Authors: Krüger, Rósaan
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68909 , vital:29338 , https://hdl.handle.net/10520/EJC85309
- Description: Publisher version , The speaker in the poem "Mending Wall" by American poet Robert Frost questions the wisdom of the saying that "Good Fences Make Good Neighbo[u]rs" (1914 North of Boston lines 27 and 45). The walls or fences referred to in the poem represent more than just physical barriers separating adjacent premises; the speaker sees them as representing obstacles to communication and friendship between individuals. Seen from the perspective of the speaker, a fence or wall is a "bad" thing. But the speaker is but one of the parties to the neighbourly relationship. For the speaker's neighbour, a wall or a fence is "a protector of privacy" (Watson "Frost's Wall : The View from the Other Side" 1971 44 The New England Quarterly 653 655). Thus there are two views on walls or fences: they can be seen negatively as obstructing good relations, or positively as dividers that secure good relations between neighbours by separating them and protecting their privacy rights.
- Full Text: false
- Date Issued: 2009
- Authors: Krüger, Rósaan
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/68909 , vital:29338 , https://hdl.handle.net/10520/EJC85309
- Description: Publisher version , The speaker in the poem "Mending Wall" by American poet Robert Frost questions the wisdom of the saying that "Good Fences Make Good Neighbo[u]rs" (1914 North of Boston lines 27 and 45). The walls or fences referred to in the poem represent more than just physical barriers separating adjacent premises; the speaker sees them as representing obstacles to communication and friendship between individuals. Seen from the perspective of the speaker, a fence or wall is a "bad" thing. But the speaker is but one of the parties to the neighbourly relationship. For the speaker's neighbour, a wall or a fence is "a protector of privacy" (Watson "Frost's Wall : The View from the Other Side" 1971 44 The New England Quarterly 653 655). Thus there are two views on walls or fences: they can be seen negatively as obstructing good relations, or positively as dividers that secure good relations between neighbours by separating them and protecting their privacy rights.
- Full Text: false
- Date Issued: 2009
Diffraction efficiency and I–V characteristics of metal-free phthalocyanine doped nematic liquid crystals
- Köysal, Oguz, Okutan, Mustafa, San, S Eren, Nyokong, Tebello, Durmus, Mahmut
- Authors: Köysal, Oguz , Okutan, Mustafa , San, S Eren , Nyokong, Tebello , Durmus, Mahmut
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263511 , vital:53634 , xlink:href="https://doi.org/10.1016/j.matchemphys.2008.10.056"
- Description: The synthesis and characterization of the tetra-4-benzyloxyphenoxy substituted metal-free phthalocyanine (H2Pc) is reported for the first time. Formation of the photoinduced gratings has been experienced in a metal-free phthalocyanine doped nematic liquid crystal (LC) system and its I–V properties are characterized by electrical measurements. Four samples are prepared at different doping percentages and in homogenously aligned sandwiched geometry. We report the results of two set of experiments on these samples. One of them is the grating diffraction experiment for the analysis of optically induced reorientation process which is a basis for possible holographic applications. Accessible diffraction efficiency is found to be linearly increasing as the amount of the phthalocyanine doping rises. In the scope of the other set of measurements I–V peculiarity of the system is also found to be enhanced and linearly dependent on doping.
- Full Text:
- Date Issued: 2009
- Authors: Köysal, Oguz , Okutan, Mustafa , San, S Eren , Nyokong, Tebello , Durmus, Mahmut
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/263511 , vital:53634 , xlink:href="https://doi.org/10.1016/j.matchemphys.2008.10.056"
- Description: The synthesis and characterization of the tetra-4-benzyloxyphenoxy substituted metal-free phthalocyanine (H2Pc) is reported for the first time. Formation of the photoinduced gratings has been experienced in a metal-free phthalocyanine doped nematic liquid crystal (LC) system and its I–V properties are characterized by electrical measurements. Four samples are prepared at different doping percentages and in homogenously aligned sandwiched geometry. We report the results of two set of experiments on these samples. One of them is the grating diffraction experiment for the analysis of optically induced reorientation process which is a basis for possible holographic applications. Accessible diffraction efficiency is found to be linearly increasing as the amount of the phthalocyanine doping rises. In the scope of the other set of measurements I–V peculiarity of the system is also found to be enhanced and linearly dependent on doping.
- Full Text:
- Date Issued: 2009
Cancer stem cells in breast cancer and metastasis:
- Lawson, Jessica C, Blatch, Gregory L, Edkins, Adrienne L
- Authors: Lawson, Jessica C , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165057 , vital:41205 , DOI: 10.1007/s10549-009-0524-9
- Description: The cancer stem cell theory poses that cancers develop from a subset of malignant cells that possess stem cell characteristics and has been proposed to account for the development of a variety of malignancies, including breast cancer. These cancer stem cells (CSC) possess characteristics of both stem cells and cancer cells, in that they have the properties of self-renewal, asymmetric cell division, resistance to apoptosis, independent growth, tumourigenicity and metastatic potential. A CSC origin for breast cancer can neatly explain both the heterogeneity of breast cancers and the relapse of the tumours after treatment. However, many reports on CSC in the breast are contradictory. There is variation with respect to how breast cancer stem cells should be identified, their characteristics and a possible lack of correlation between clinical outcome and breast cancer stem cell status of a tumour. These combined factors have made breast cancer stem cells a highly contentious issue. In this review, we highlight the progress in the analysis of cancer stem cells, with an emphasis on breast cancer.
- Full Text:
- Date Issued: 2009
- Authors: Lawson, Jessica C , Blatch, Gregory L , Edkins, Adrienne L
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/165057 , vital:41205 , DOI: 10.1007/s10549-009-0524-9
- Description: The cancer stem cell theory poses that cancers develop from a subset of malignant cells that possess stem cell characteristics and has been proposed to account for the development of a variety of malignancies, including breast cancer. These cancer stem cells (CSC) possess characteristics of both stem cells and cancer cells, in that they have the properties of self-renewal, asymmetric cell division, resistance to apoptosis, independent growth, tumourigenicity and metastatic potential. A CSC origin for breast cancer can neatly explain both the heterogeneity of breast cancers and the relapse of the tumours after treatment. However, many reports on CSC in the breast are contradictory. There is variation with respect to how breast cancer stem cells should be identified, their characteristics and a possible lack of correlation between clinical outcome and breast cancer stem cell status of a tumour. These combined factors have made breast cancer stem cells a highly contentious issue. In this review, we highlight the progress in the analysis of cancer stem cells, with an emphasis on breast cancer.
- Full Text:
- Date Issued: 2009
Editorial: environmental-education research in the year of COP 15
- Lotz-Sisitka, Heila, Kronlid, David O
- Authors: Lotz-Sisitka, Heila , Kronlid, David O
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67356 , vital:29080 , https://www.ajol.info/index.php/sajee/article/view/122784
- Description: publisher version , Introduction: This year there has literally been a cacophony surrounding the implications of climate change, as the world geared up for the 15th Conference of the Parties (COP 15) in Copenhagen, where it was expected that the largest ever gathering of world leaders would sign binding agreements to reduce carbon emissions to keep global temperatures from rising by more than 2⁰C. As we make the final contributions to the refinement of this editorial, late in December 2009, it is concerning to note that this did not happen, that civil society voices were marginalised at the COP 15 and that there has been little progress on a socially just and ecologically sound global climate change deal. The stark reality remains that developing countries – southern African countries in particular – remain most vulnerable to the risks associated with global climate change. Havnevik (2007) stated a while ago that: The ways in which poverty, consumption and climate change are addressed, tend to blur historical, structural and power features underlying global inequalities. This makes possible the focus on market forces, such as carbon trading, to resolve the problems. However, these market solutions will not suffice, and may only delay a real solution, which will then have to be developed in a situation of more acute global social injustice and possibly deeper conflicts … Issues related to inequality, energy and climate are of a global character: there is no longer one solution for the South and one for the North. (18,19) So where does the current state of climate change and the political failures surrounding responses to climate change leave education research in developing and developed nations? What are the implications for environmental education researchers in southern Africa and elsewhere? These are some of the questions pondered in this edition of the Southern African Journal of Environmental Education (SAJEE). As one of us (Kronlid) reflects in a Think Piece in this journal: ‘the world is one and many and … the complexities associated with climate change means that we have a shared global systematic problem manifested in a myriad different concrete ways in people’s everyday life throughout the globe. We need many different kinds and modes of climate change education research’ (Kronlid, this edition).
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila , Kronlid, David O
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67356 , vital:29080 , https://www.ajol.info/index.php/sajee/article/view/122784
- Description: publisher version , Introduction: This year there has literally been a cacophony surrounding the implications of climate change, as the world geared up for the 15th Conference of the Parties (COP 15) in Copenhagen, where it was expected that the largest ever gathering of world leaders would sign binding agreements to reduce carbon emissions to keep global temperatures from rising by more than 2⁰C. As we make the final contributions to the refinement of this editorial, late in December 2009, it is concerning to note that this did not happen, that civil society voices were marginalised at the COP 15 and that there has been little progress on a socially just and ecologically sound global climate change deal. The stark reality remains that developing countries – southern African countries in particular – remain most vulnerable to the risks associated with global climate change. Havnevik (2007) stated a while ago that: The ways in which poverty, consumption and climate change are addressed, tend to blur historical, structural and power features underlying global inequalities. This makes possible the focus on market forces, such as carbon trading, to resolve the problems. However, these market solutions will not suffice, and may only delay a real solution, which will then have to be developed in a situation of more acute global social injustice and possibly deeper conflicts … Issues related to inequality, energy and climate are of a global character: there is no longer one solution for the South and one for the North. (18,19) So where does the current state of climate change and the political failures surrounding responses to climate change leave education research in developing and developed nations? What are the implications for environmental education researchers in southern Africa and elsewhere? These are some of the questions pondered in this edition of the Southern African Journal of Environmental Education (SAJEE). As one of us (Kronlid) reflects in a Think Piece in this journal: ‘the world is one and many and … the complexities associated with climate change means that we have a shared global systematic problem manifested in a myriad different concrete ways in people’s everyday life throughout the globe. We need many different kinds and modes of climate change education research’ (Kronlid, this edition).
- Full Text:
- Date Issued: 2009
Sigtuna Think Piece 8: Piecing together conceptual framings for climate change education research in southern African contexts
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67378 , vital:29082 , https://www.ajol.info/index.php/sajee/article/view/122808
- Description: publisher version , This think piece considers a range of theoretical and conceptual tools that may assist with the emergence of a research agenda for climate change in education. It considers the conditions that are created by climate change in and for southern African contexts, and then deliberates which contextually related theoretical tools may be useful to frame research questions for climate change education. I consider the educational research implications of adaptation practices, reflexive justice and agency, reflexivity and capability, noting that a climate change education research agenda, not different to a wider reflexive environmental education research agenda dealing with transformative praxis in southern Africa, is essentially a sociologically and historically emergent ‘researching with’ agenda, and is in effect a social learning process. In putting together these conceptual framings for a climate change research agenda in southern Africa, I am interested in exploring how participatory social learning research may strengthen agency and reflexivity (development of capabilities) in response to socio-ecological conditions.
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/67378 , vital:29082 , https://www.ajol.info/index.php/sajee/article/view/122808
- Description: publisher version , This think piece considers a range of theoretical and conceptual tools that may assist with the emergence of a research agenda for climate change in education. It considers the conditions that are created by climate change in and for southern African contexts, and then deliberates which contextually related theoretical tools may be useful to frame research questions for climate change education. I consider the educational research implications of adaptation practices, reflexive justice and agency, reflexivity and capability, noting that a climate change education research agenda, not different to a wider reflexive environmental education research agenda dealing with transformative praxis in southern Africa, is essentially a sociologically and historically emergent ‘researching with’ agenda, and is in effect a social learning process. In putting together these conceptual framings for a climate change research agenda in southern Africa, I am interested in exploring how participatory social learning research may strengthen agency and reflexivity (development of capabilities) in response to socio-ecological conditions.
- Full Text:
- Date Issued: 2009
Utopianism and educational processes in the United Nations Decade of Education for Sustainable Development
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184756 , vital:44269 , xlink:href="https://cjee.lakeheadu.ca/article/view/866"
- Description: Recent international policy literature on Education for Sustainable Development puts forward utopian concepts of sustainable development and transformed learning as objects for educational thinking and practice. This paper, drawing on three illustrative educational investigations with youth in a South African context, critically examines how we might engage with utopian concepts such as those put forward in the United Nations Decade of Education for Sustainable Development. It incorporates an engagement with other related utopian concepts such as democracy and social justice, which feature strongly in post-apartheid societal reconstruction in South Africa. The paper argues that if we are to avoid valuable utopian concepts such as democracy, sustainability, and social justice from becoming doxic knowledge, a reflexive realist orientation might best guide our educational engagements with such concepts. Such an approach to utopianism would take account of contextual realities and situated learning processes, and foster a creativity of action that is constructivist in nature, but not relativist.
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/184756 , vital:44269 , xlink:href="https://cjee.lakeheadu.ca/article/view/866"
- Description: Recent international policy literature on Education for Sustainable Development puts forward utopian concepts of sustainable development and transformed learning as objects for educational thinking and practice. This paper, drawing on three illustrative educational investigations with youth in a South African context, critically examines how we might engage with utopian concepts such as those put forward in the United Nations Decade of Education for Sustainable Development. It incorporates an engagement with other related utopian concepts such as democracy and social justice, which feature strongly in post-apartheid societal reconstruction in South Africa. The paper argues that if we are to avoid valuable utopian concepts such as democracy, sustainability, and social justice from becoming doxic knowledge, a reflexive realist orientation might best guide our educational engagements with such concepts. Such an approach to utopianism would take account of contextual realities and situated learning processes, and foster a creativity of action that is constructivist in nature, but not relativist.
- Full Text:
- Date Issued: 2009
How many declarations do we need?: Inside the drafting of the Bonn Declaration on education for sustainable development
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182522 , vital:43837 , xlink:href="https://doi.org/10.1177/097340820900300217"
- Description: The Bonn Declaration, approved by the 900 participants at the UNESCO World Conference on Sustainable Development, differs from other conference declarations in that it is the first declaration to deal exclusively with education for sustainable development. It received input from official State representatives and, perhaps because of that, it is somewhat less provocative than some nongovernmental or university-sponsored declarations. Also, it actually sets out, with some authority, an agenda for UNESCO, the manager of the UN Decade of Education for Sustainable Development. Though some may question the usefulness of conference declarations, history shows that such declarations do have at least some guiding power in that they provide common starting points for deliberation on possible changes at national and international levels.
- Full Text:
- Date Issued: 2009
- Authors: Lotz-Sisitka, Heila
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/182522 , vital:43837 , xlink:href="https://doi.org/10.1177/097340820900300217"
- Description: The Bonn Declaration, approved by the 900 participants at the UNESCO World Conference on Sustainable Development, differs from other conference declarations in that it is the first declaration to deal exclusively with education for sustainable development. It received input from official State representatives and, perhaps because of that, it is somewhat less provocative than some nongovernmental or university-sponsored declarations. Also, it actually sets out, with some authority, an agenda for UNESCO, the manager of the UN Decade of Education for Sustainable Development. Though some may question the usefulness of conference declarations, history shows that such declarations do have at least some guiding power in that they provide common starting points for deliberation on possible changes at national and international levels.
- Full Text:
- Date Issued: 2009