Environmental domains and range-limiting mechanisms: testing the Abundant Centre Hypothesis using southern African sandhoppers
- Baldanzi, Simone, McQuaid, Christopher D, Cannicci, Stefano, Porri, Francesca
- Authors: Baldanzi, Simone , McQuaid, Christopher D , Cannicci, Stefano , Porri, Francesca
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6848 , http://hdl.handle.net/10962/d1011108
- Description: Predicting shifts of species geographical ranges is a fundamental challenge for conservation ecologists given the great complexity of factors involved in setting range limits. Distributional patterns are frequently modelled to “simplify” species responses to the environment, yet the central mechanisms that drive a particular pattern are rarely understood. We evaluated the distributions of two sandhopper species (Crustacea, Amphipoda, Talitridae), Talorchestia capensis and Africorchestia quadrispinosa along the Namibian and South African coasts, encompassing three biogeographic regions influenced by two different oceanographic systems, the Benguela and Agulhas currents. We aimed to test whether the Abundant Centre Hypothesis (ACH) can explain the distributions of these species’ abundances, sizes and sex ratios and examined which environmental parameters influence/drive these distributions. Animals were collected during a once-off survey at 29 sites over c.3500 km of coastline. The ACH was tested using a non-parametric constraint space analysis of the goodness of fit of five hypothetical models. Distance Based Linear Modelling (DistLM) was performed to evaluate which environmental traits influenced the distribution data. Abundance, size and sex ratio showed different patterns of distribution. A ramped model fitted the abundance (Ramped North) and size (Ramped South) distribution for A. quadrispinosa. The Inverse Quadratic model fitted the size distribution of T. capensis. Beach slope, salinity, sand temperature and percentage of detritus found on the shore at the time of collection played important roles in driving the abundance of A. quadrispinosa. T. capensis was mainly affected by salinity and the morphodynamic state of the beach. Our results provided only some support for the ACH predictions. The DistLM confirmed that the physical state of the beach is an important factor for sandy beach organisms. The effect of salinity and temperature suggest metabolic responses to local conditions and a role in small to mesoscale shifts in the range of these populations.
- Full Text:
- Date Issued: 2013
- Authors: Baldanzi, Simone , McQuaid, Christopher D , Cannicci, Stefano , Porri, Francesca
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6848 , http://hdl.handle.net/10962/d1011108
- Description: Predicting shifts of species geographical ranges is a fundamental challenge for conservation ecologists given the great complexity of factors involved in setting range limits. Distributional patterns are frequently modelled to “simplify” species responses to the environment, yet the central mechanisms that drive a particular pattern are rarely understood. We evaluated the distributions of two sandhopper species (Crustacea, Amphipoda, Talitridae), Talorchestia capensis and Africorchestia quadrispinosa along the Namibian and South African coasts, encompassing three biogeographic regions influenced by two different oceanographic systems, the Benguela and Agulhas currents. We aimed to test whether the Abundant Centre Hypothesis (ACH) can explain the distributions of these species’ abundances, sizes and sex ratios and examined which environmental parameters influence/drive these distributions. Animals were collected during a once-off survey at 29 sites over c.3500 km of coastline. The ACH was tested using a non-parametric constraint space analysis of the goodness of fit of five hypothetical models. Distance Based Linear Modelling (DistLM) was performed to evaluate which environmental traits influenced the distribution data. Abundance, size and sex ratio showed different patterns of distribution. A ramped model fitted the abundance (Ramped North) and size (Ramped South) distribution for A. quadrispinosa. The Inverse Quadratic model fitted the size distribution of T. capensis. Beach slope, salinity, sand temperature and percentage of detritus found on the shore at the time of collection played important roles in driving the abundance of A. quadrispinosa. T. capensis was mainly affected by salinity and the morphodynamic state of the beach. Our results provided only some support for the ACH predictions. The DistLM confirmed that the physical state of the beach is an important factor for sandy beach organisms. The effect of salinity and temperature suggest metabolic responses to local conditions and a role in small to mesoscale shifts in the range of these populations.
- Full Text:
- Date Issued: 2013
A tale of two neglected systems-structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves
- Authors: Botha, Christiaan E J
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: vital:6499 , http://hdl.handle.net/10962/d1004514 , http://dx.doi.org/10.3389/fpls.2013.00297
- Description: There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5–7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.
- Full Text:
- Date Issued: 2013
- Authors: Botha, Christiaan E J
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: vital:6499 , http://hdl.handle.net/10962/d1004514 , http://dx.doi.org/10.3389/fpls.2013.00297
- Description: There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5–7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.
- Full Text:
- Date Issued: 2013
Observables in a lattice Universe : the cosmological fitting problem
- Bruneton, J-P, Larena, Julien
- Authors: Bruneton, J-P , Larena, Julien
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6790 , http://hdl.handle.net/10962/d1006943
- Description: We explore observables in a lattice Universe described by a recently found solution to Einstein field equations. This solution models a regular lattice of evenly distributed objects of equal masses. This inhomogeneous solution is perturbative, and, up to second order in a small parameter, it expands at a rate exactly equal to the one expected in a dust dominated Friedmann-Lema^itre-Robertson-Walker (FLRW) model with the equivalent, smoothed, energy density. Therefore, the kinematics of both cosmologies are identical up to the order of perturbation studied. Looking at the behaviour of the redshift and angular distance, we find a condition on the compactness of the objects at the centre of each cell under which corrections to the FLRW observables remain small, i.e. of order of a few percents at most. Nevertheless, we show that, if this condition is violated, i.e. if the objects are too compact, our perturbative scheme breaks down as far as the calculations of observables are concerned, even though the kinematics of the lattice remains identical to its FLRW counter-part (at the perturbative order considered). This may be an indication of an actual fitting problem, i.e. a situation in which the FLRW model obtained from lightcone observables does not correspond to the FLRW model obtained by smoothing the spatial distribution of matter. Fully non-perturbative treatments of the observables will be necessary to answer that question.
- Full Text:
- Date Issued: 2013
- Authors: Bruneton, J-P , Larena, Julien
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6790 , http://hdl.handle.net/10962/d1006943
- Description: We explore observables in a lattice Universe described by a recently found solution to Einstein field equations. This solution models a regular lattice of evenly distributed objects of equal masses. This inhomogeneous solution is perturbative, and, up to second order in a small parameter, it expands at a rate exactly equal to the one expected in a dust dominated Friedmann-Lema^itre-Robertson-Walker (FLRW) model with the equivalent, smoothed, energy density. Therefore, the kinematics of both cosmologies are identical up to the order of perturbation studied. Looking at the behaviour of the redshift and angular distance, we find a condition on the compactness of the objects at the centre of each cell under which corrections to the FLRW observables remain small, i.e. of order of a few percents at most. Nevertheless, we show that, if this condition is violated, i.e. if the objects are too compact, our perturbative scheme breaks down as far as the calculations of observables are concerned, even though the kinematics of the lattice remains identical to its FLRW counter-part (at the perturbative order considered). This may be an indication of an actual fitting problem, i.e. a situation in which the FLRW model obtained from lightcone observables does not correspond to the FLRW model obtained by smoothing the spatial distribution of matter. Fully non-perturbative treatments of the observables will be necessary to answer that question.
- Full Text:
- Date Issued: 2013
Graviton multipoint functions at the AdS boundary
- Authors: Brustein, R , Medved, A J M
- Date: 2013
- Language: English
- Type: text , Article
- Identifier: vital:6819 , http://hdl.handle.net/10962/d1004425
- Description: The gauge-gravity duality can be used to relate connected multipoint graviton functions to connected multipoint correlation functions of the stress tensor of a strongly coupled fluid. Here, we show how to construct the connected graviton functions for a particular kinematic regime that is ideal for discriminating between different gravitational theories, in particular between Einstein theory and its leading-order string theory correction. Our analysis begins with the one-particle irreducible graviton amplitudes in an anti-de Sitter black brane background.We show how these can be used to calculate the connected graviton functions and demonstrate that the two types of amplitudes agree in some cases. It is then asserted on physical grounds that this agreement persists in all cases for both Einstein gravity and its leading-order correction. This outcome implies that the corresponding field-theory correlation functions can be read off directly from the bulk Lagrangian, just as can be done for the ratio of the shear viscosity to the entropy density.
- Full Text:
- Date Issued: 2013
- Authors: Brustein, R , Medved, A J M
- Date: 2013
- Language: English
- Type: text , Article
- Identifier: vital:6819 , http://hdl.handle.net/10962/d1004425
- Description: The gauge-gravity duality can be used to relate connected multipoint graviton functions to connected multipoint correlation functions of the stress tensor of a strongly coupled fluid. Here, we show how to construct the connected graviton functions for a particular kinematic regime that is ideal for discriminating between different gravitational theories, in particular between Einstein theory and its leading-order string theory correction. Our analysis begins with the one-particle irreducible graviton amplitudes in an anti-de Sitter black brane background.We show how these can be used to calculate the connected graviton functions and demonstrate that the two types of amplitudes agree in some cases. It is then asserted on physical grounds that this agreement persists in all cases for both Einstein gravity and its leading-order correction. This outcome implies that the corresponding field-theory correlation functions can be read off directly from the bulk Lagrangian, just as can be done for the ratio of the shear viscosity to the entropy density.
- Full Text:
- Date Issued: 2013
Responsive integrative treatment of PTSD and trauma related disorders : an expanded evidence-based model
- Authors: Edwards, David J A
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6223 , http://hdl.handle.net/10962/d1007679
- Description: In this article a practitioner oriented review of the literature on the treatment of post-traumatic stress disorder is used to construct a phase-based model that can serve as a basis for case formulation and treatment planning. Treatments shown to be efficacious in randomized controlled trials are listed and two discourses about them are contrasted. One calls for therapists to implement treatments scrupulously according to the manual, the other calls for flexibility and responsiveness to contextual understanding of the situation and personality of individual clients. Evidence for the centrality of the principles of this latter discourse for professional practice is summarized from work on case formulation, standards for therapist competence, and the concept of evidence-based practice. This provides the foundation for a model for treatment of PTSD, both simple and complex, that has five levels which represent increasing degrees of depth of clinical work. In accordance with the phased approach, conditions at one level need to be satisfied before proceeding to work on a deeper level. At each level specific areas of clinical focus are highlighted including risk management (at level 1), building the therapeutic alliance (at level 2) and trauma-focused work (at level 3). The model serves as a broad structured summary of accumulated clinical knowledge about PTSD and its treatment that provides an evidence-based foundation for assessment and treatment planning.
- Full Text:
- Date Issued: 2013
- Authors: Edwards, David J A
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6223 , http://hdl.handle.net/10962/d1007679
- Description: In this article a practitioner oriented review of the literature on the treatment of post-traumatic stress disorder is used to construct a phase-based model that can serve as a basis for case formulation and treatment planning. Treatments shown to be efficacious in randomized controlled trials are listed and two discourses about them are contrasted. One calls for therapists to implement treatments scrupulously according to the manual, the other calls for flexibility and responsiveness to contextual understanding of the situation and personality of individual clients. Evidence for the centrality of the principles of this latter discourse for professional practice is summarized from work on case formulation, standards for therapist competence, and the concept of evidence-based practice. This provides the foundation for a model for treatment of PTSD, both simple and complex, that has five levels which represent increasing degrees of depth of clinical work. In accordance with the phased approach, conditions at one level need to be satisfied before proceeding to work on a deeper level. At each level specific areas of clinical focus are highlighted including risk management (at level 1), building the therapeutic alliance (at level 2) and trauma-focused work (at level 3). The model serves as a broad structured summary of accumulated clinical knowledge about PTSD and its treatment that provides an evidence-based foundation for assessment and treatment planning.
- Full Text:
- Date Issued: 2013
From panic disorder to complex traumatic stress disorder : retrospective reflections on the case of Tariq
- Authors: Edwards, David J A
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6234 , http://hdl.handle.net/10962/d1007784
- Description: This is a phenomenological-hermeneutic case study of Tariq who initially presented with panic disorder. It documents how, as therapy proceeded, the underlying meaning of his initial panic deepened as its roots in traumatic memories of childhood emerged. There were four spaced phases of treatment over four years. The first focused on anxiety management; the second was conceptualized within schema-focused therapy, and evoked and worked with childhood memories using inner child guided imagery; in the third and fourth phases insights gained led to an authentic re-engagement with family members in relationships that had been problematic. The panic attacks resolved and there were two dreams representing a reconfiguring of his relationship with his deceased father. The first two phases were the focus of an unpublished case study presented at a conference in 1995. This article incorporates material from that study and looks back at the case both in light of developments in phases two and three and also in light of theoretical developments in our understanding of complex trauma since the initial presentation.
- Full Text:
- Date Issued: 2013
- Authors: Edwards, David J A
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6234 , http://hdl.handle.net/10962/d1007784
- Description: This is a phenomenological-hermeneutic case study of Tariq who initially presented with panic disorder. It documents how, as therapy proceeded, the underlying meaning of his initial panic deepened as its roots in traumatic memories of childhood emerged. There were four spaced phases of treatment over four years. The first focused on anxiety management; the second was conceptualized within schema-focused therapy, and evoked and worked with childhood memories using inner child guided imagery; in the third and fourth phases insights gained led to an authentic re-engagement with family members in relationships that had been problematic. The panic attacks resolved and there were two dreams representing a reconfiguring of his relationship with his deceased father. The first two phases were the focus of an unpublished case study presented at a conference in 1995. This article incorporates material from that study and looks back at the case both in light of developments in phases two and three and also in light of theoretical developments in our understanding of complex trauma since the initial presentation.
- Full Text:
- Date Issued: 2013
Extreme weather events in the Sneeuberg, Karoo, South Africa: a case study of the floods of 9 and 12 February 2011
- Fox, Roddy C, Rowntree, Kate M
- Authors: Fox, Roddy C , Rowntree, Kate M
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6672 , http://hdl.handle.net/10962/d1004468
- Description: Two destructive flood events occurred in rapid succession in the semi-arid Sneeuberg Mountains of the Karoo, South Africa in February 2011. The temporal and spatial characteristics of these two extreme events are examined in this paper through analysis of data from an unusually dense, and reliable, network of farm rain gauges. These analyses add to our understanding derived from existing rain gauge information. Comparisons are then made with patterns from a range of modeled products derived from remote sensed information: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), the Tropical Rainfall Measuring Mission (TRMM) and the Global Land Data Assimilation System (GLDAS). We found that the first flood event was widespread and precipitation was related strongly to altitude. The second was highly localised, with no relationship to altitude. Both had very sharply peaked rainfall intensities. These findings are of significance to the studies of flooding and landscape change in the area as such events have become more pronounced over the past 50 yr and it is likely that this trend will accelerate. The modeled patterns are derived largely from remote sensing and we found that they are reliable for drawing out monthly and annual variations but they make noticeable underestimates. They are poor estimates, however, both for the spatial distribution of precipitation, and the short term trends as they struggle to estimate the impact of topography and other local forcing factors. This finding corroborates information derived from other analyses at broader spatial scales using more widely spread, established rain gauge stations. Ten percent of southern Africa has been classified as mountainous and these areas provide much of our water resources so our findings are significant to water managers throughout this and similar mountainous regions.
- Full Text:
- Date Issued: 2013
- Authors: Fox, Roddy C , Rowntree, Kate M
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6672 , http://hdl.handle.net/10962/d1004468
- Description: Two destructive flood events occurred in rapid succession in the semi-arid Sneeuberg Mountains of the Karoo, South Africa in February 2011. The temporal and spatial characteristics of these two extreme events are examined in this paper through analysis of data from an unusually dense, and reliable, network of farm rain gauges. These analyses add to our understanding derived from existing rain gauge information. Comparisons are then made with patterns from a range of modeled products derived from remote sensed information: the Modern-Era Retrospective Analysis for Research and Applications (MERRA), the Tropical Rainfall Measuring Mission (TRMM) and the Global Land Data Assimilation System (GLDAS). We found that the first flood event was widespread and precipitation was related strongly to altitude. The second was highly localised, with no relationship to altitude. Both had very sharply peaked rainfall intensities. These findings are of significance to the studies of flooding and landscape change in the area as such events have become more pronounced over the past 50 yr and it is likely that this trend will accelerate. The modeled patterns are derived largely from remote sensing and we found that they are reliable for drawing out monthly and annual variations but they make noticeable underestimates. They are poor estimates, however, both for the spatial distribution of precipitation, and the short term trends as they struggle to estimate the impact of topography and other local forcing factors. This finding corroborates information derived from other analyses at broader spatial scales using more widely spread, established rain gauge stations. Ten percent of southern Africa has been classified as mountainous and these areas provide much of our water resources so our findings are significant to water managers throughout this and similar mountainous regions.
- Full Text:
- Date Issued: 2013
Towards an exceptional Undergraduate Personal Learning Experience: the Personal Librarian Programme, a pilot project at Rhodes University Library
- Authors: Gontshi, V
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6985 , http://hdl.handle.net/10962/d1007918
- Description: This paper is a record of a unique intervention for enhancing the undergraduate learning experience at Rhodes University. It focuses on the establishment of the project, the experiences encountered and lessons learned thus far. In April 2013, a team of 13 librarians embarked on a Personal Librarian Pilot Project at the Rhodes University Library. The Personal Librarian Programme is primarily directed at undergraduate students at Rhodes University. In an attempt to bridge the information literacy skills gap that exists between Senior School and University in South Africa, the idea behind this programme is that each incoming first year student is assigned a Personal Librarian who will remain that individual’s contact in the library throughout his/her academic career at Rhodes University. The project came about as a result of research exploring the perceptions of both students and lecturers in the Commerce Faculty at Rhodes University with regard to Information Literacy practices and needs (Gontshi, 2011). The study revealed and recorded a shortcoming in the Information Literacy ability of students between Senior School Level and University Level. It became clear that new University students were not aware of the important link between their academic studies and the Library which in turn suggested the need to make Rhodes University librarians and the role that they play in the academic world more obvious to these new students (Gontshi, 2011). The Personal Librarian Programme was devised to fill this need. The Librarians involved in this programme include staff from all sections of the Library: circulation, faculty liaison and bibliographic/technical services. The training needs of staff who did not work directly with students were identified and the relevant training provided. The staff from circulation and bibliographic/technical services sections identified a need to advance their knowledge in the use of the library from a users’ perspective. The training focused on the following: “Brainstorming a research topic with a student”; “Identifying relevant databases to conduct a research topic” and “Conducting a search on relevant databases for the research topic” – this included different ways of devising an effective search technique. The training ensured a good foundation for these librarians to develop their confidence to work with users. The project, modeled on a similar programme at the Yale University Library in the United States of America, was also a direct result of Rhodes University Library’s involvement in the Carnegie Research Libraries Consortium (2009 – 2011) and the author’s ten-week internship in the United States, seven weeks of which were spent at Yale University.
- Full Text:
- Date Issued: 2013
- Authors: Gontshi, V
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6985 , http://hdl.handle.net/10962/d1007918
- Description: This paper is a record of a unique intervention for enhancing the undergraduate learning experience at Rhodes University. It focuses on the establishment of the project, the experiences encountered and lessons learned thus far. In April 2013, a team of 13 librarians embarked on a Personal Librarian Pilot Project at the Rhodes University Library. The Personal Librarian Programme is primarily directed at undergraduate students at Rhodes University. In an attempt to bridge the information literacy skills gap that exists between Senior School and University in South Africa, the idea behind this programme is that each incoming first year student is assigned a Personal Librarian who will remain that individual’s contact in the library throughout his/her academic career at Rhodes University. The project came about as a result of research exploring the perceptions of both students and lecturers in the Commerce Faculty at Rhodes University with regard to Information Literacy practices and needs (Gontshi, 2011). The study revealed and recorded a shortcoming in the Information Literacy ability of students between Senior School Level and University Level. It became clear that new University students were not aware of the important link between their academic studies and the Library which in turn suggested the need to make Rhodes University librarians and the role that they play in the academic world more obvious to these new students (Gontshi, 2011). The Personal Librarian Programme was devised to fill this need. The Librarians involved in this programme include staff from all sections of the Library: circulation, faculty liaison and bibliographic/technical services. The training needs of staff who did not work directly with students were identified and the relevant training provided. The staff from circulation and bibliographic/technical services sections identified a need to advance their knowledge in the use of the library from a users’ perspective. The training focused on the following: “Brainstorming a research topic with a student”; “Identifying relevant databases to conduct a research topic” and “Conducting a search on relevant databases for the research topic” – this included different ways of devising an effective search technique. The training ensured a good foundation for these librarians to develop their confidence to work with users. The project, modeled on a similar programme at the Yale University Library in the United States of America, was also a direct result of Rhodes University Library’s involvement in the Carnegie Research Libraries Consortium (2009 – 2011) and the author’s ten-week internship in the United States, seven weeks of which were spent at Yale University.
- Full Text:
- Date Issued: 2013
Plasmodium falciparum Hsp70-x : a heat shock protein at the host-parasite interface
- Hatherley, R, Blatch, Gregory L, Tastan Bishop, Özlem
- Authors: Hatherley, R , Blatch, Gregory L , Tastan Bishop, Özlem
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6489 , http://hdl.handle.net/10962/d1007081 , https://dx.doi.org/10.1080/07391102.2013.834849
- Description: Plasmodium falciparum 70 kDa heat shock proteins (PfHsp70s) are expressed at all stages of the pathogenic erythrocytic phase of the malaria parasite lifecycle. There are six PfHsp70s,all of which have orthologues in other plasmodial species, except for PfHsp70-x which is unique to P. falciparum. This paper highlights a number of original results obtained by a detailed bioinformatics analysis of the protein. Large scale sequence analysis indicated the presence of an extended transit peptide sequence of PfHsp70-x which potentially directs it to the endoplasmic reticulum (ER). Further analysis showed that PfHsp70-x does not have an ER-retention sequence, suggesting that the protein transits through the ER and is secreted into the parasitophorous vacuole (PV) or beyond into the erythrocyte cytosol. These results are consistent with experimental findings. Next, possible interactions between PfHsp70-x and exported P. falciparum Hsp40s or host erythrocyte DnaJs were interrogated by modeling and docking. Docking results indicated that interaction between PfHsp70-x and each of the Hsp40s, regardless of biological feasibility, seems equally likely. This suggests that J domain might not provide the specificity in the formation of unique Hsp70-Hsp40 complexes, but that the specificity might be provided by other domains of Hsp40s. By studying different structural conformations of PfHsp70-x, it was shown that Hsp40s can only bind when PfHsp70-x is in a certain conformation. Additionally, this work highlighted the possible dependence of the substrate binding domain residues on the orientation of the α-helical lid for formation of the substrate binding pocket.
- Full Text:
- Date Issued: 2013
- Authors: Hatherley, R , Blatch, Gregory L , Tastan Bishop, Özlem
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6489 , http://hdl.handle.net/10962/d1007081 , https://dx.doi.org/10.1080/07391102.2013.834849
- Description: Plasmodium falciparum 70 kDa heat shock proteins (PfHsp70s) are expressed at all stages of the pathogenic erythrocytic phase of the malaria parasite lifecycle. There are six PfHsp70s,all of which have orthologues in other plasmodial species, except for PfHsp70-x which is unique to P. falciparum. This paper highlights a number of original results obtained by a detailed bioinformatics analysis of the protein. Large scale sequence analysis indicated the presence of an extended transit peptide sequence of PfHsp70-x which potentially directs it to the endoplasmic reticulum (ER). Further analysis showed that PfHsp70-x does not have an ER-retention sequence, suggesting that the protein transits through the ER and is secreted into the parasitophorous vacuole (PV) or beyond into the erythrocyte cytosol. These results are consistent with experimental findings. Next, possible interactions between PfHsp70-x and exported P. falciparum Hsp40s or host erythrocyte DnaJs were interrogated by modeling and docking. Docking results indicated that interaction between PfHsp70-x and each of the Hsp40s, regardless of biological feasibility, seems equally likely. This suggests that J domain might not provide the specificity in the formation of unique Hsp70-Hsp40 complexes, but that the specificity might be provided by other domains of Hsp40s. By studying different structural conformations of PfHsp70-x, it was shown that Hsp40s can only bind when PfHsp70-x is in a certain conformation. Additionally, this work highlighted the possible dependence of the substrate binding domain residues on the orientation of the α-helical lid for formation of the substrate binding pocket.
- Full Text:
- Date Issued: 2013
Form over function? The practical application of the Recognition of Customary Marriages Act 1998 in South Africa
- Authors: Kruuse, Helen
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54094 , vital:26389 , http://journals.co.za/content/ju_jur/2013/1/EJC148455
- Description: The Recognition of Customary Marriages Act 120 of 1998 is a major legislative measure for the development of customary marriages in line with the constitutional principle of equality, specifically for women. The article explores the interactions between this ideal in the Act with empirical observations and the latest judicial decisions concerning its application. It considers various examples of the lack of protection of women in relationships of a customary nature, and it concludes that both the state and courts favour a formal or definitional approach to customary marriage. In considering alternative approaches that could adequately protect vulnerable parties, two conclusions emerge: First, the article recommends a wholesale revision of the South African family law approach from a focus on form to dependency. Second (and as a short-term measure), the article advocates for the putative marriage doctrine to be applied in the customary marriage context to protect many women who are denied access to 'customary marriage' as a form, and as a result, all of the benefits that flow from such marriage.
- Full Text:
- Date Issued: 2013
- Authors: Kruuse, Helen
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54094 , vital:26389 , http://journals.co.za/content/ju_jur/2013/1/EJC148455
- Description: The Recognition of Customary Marriages Act 120 of 1998 is a major legislative measure for the development of customary marriages in line with the constitutional principle of equality, specifically for women. The article explores the interactions between this ideal in the Act with empirical observations and the latest judicial decisions concerning its application. It considers various examples of the lack of protection of women in relationships of a customary nature, and it concludes that both the state and courts favour a formal or definitional approach to customary marriage. In considering alternative approaches that could adequately protect vulnerable parties, two conclusions emerge: First, the article recommends a wholesale revision of the South African family law approach from a focus on form to dependency. Second (and as a short-term measure), the article advocates for the putative marriage doctrine to be applied in the customary marriage context to protect many women who are denied access to 'customary marriage' as a form, and as a result, all of the benefits that flow from such marriage.
- Full Text:
- Date Issued: 2013
You reap what you sow : regulating marriages and intimate partnerships in a diverse post-apartheid society
- Authors: Kruuse, Helen
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54152 , vital:26396 , https://tinyurl.com/yaughtn2
- Description: South Africa does not have a particularly proud history. Marred by the politics of separate but (un)equal treatment of its people, the country's past political system has had a damaging effect in all spheres, but specifically on that of the family. In the context of relationships, it is fair to say that the apartheid system was replicated in family law, with the Western 'white' monogamous marriage receiving the state's stamp of approval - leaving other relationships (customary, Muslim, homosexual, cohabiting etc) largely out in the cold.
- Full Text:
- Date Issued: 2013
- Authors: Kruuse, Helen
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: http://hdl.handle.net/10962/54152 , vital:26396 , https://tinyurl.com/yaughtn2
- Description: South Africa does not have a particularly proud history. Marred by the politics of separate but (un)equal treatment of its people, the country's past political system has had a damaging effect in all spheres, but specifically on that of the family. In the context of relationships, it is fair to say that the apartheid system was replicated in family law, with the Western 'white' monogamous marriage receiving the state's stamp of approval - leaving other relationships (customary, Muslim, homosexual, cohabiting etc) largely out in the cold.
- Full Text:
- Date Issued: 2013
Obituary: John Mayne English 1922-2013
- Authors: Lewis, Colin A
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: vital:6162 , http://hdl.handle.net/10962/d1004782
- Description: In 1962 John moved south to Johannesburg, but that bustling city held few attractions for him and he moved further south, to the cathedral city of Grahamstown. Grahamstown, with its nineteenth century Gothic cathedral, elegant Georgian buildings, and distinctive grandeur of Rhodes University, St Andrew's College and other buildings designed by Herbert Baker and his colleagues, suited John. He particularly enjoyed the academic, social, artistic and dramatic life of the community, where many older members of society were distinguished old-Africa hands. John thoroughly enjoyed Grahamstown where, in the partnership of Hoskins and English, he made his mark in the restoration and extension of many significant buildings. His addition to the Anglican chapel at Hog's Back is a masterpiece, as is his incorporation of the old fayade into the rebuilding and extension of the Magistrates' Court.
- Full Text:
- Date Issued: 2013
- Authors: Lewis, Colin A
- Date: 2013
- Language: English
- Type: Article , text
- Identifier: vital:6162 , http://hdl.handle.net/10962/d1004782
- Description: In 1962 John moved south to Johannesburg, but that bustling city held few attractions for him and he moved further south, to the cathedral city of Grahamstown. Grahamstown, with its nineteenth century Gothic cathedral, elegant Georgian buildings, and distinctive grandeur of Rhodes University, St Andrew's College and other buildings designed by Herbert Baker and his colleagues, suited John. He particularly enjoyed the academic, social, artistic and dramatic life of the community, where many older members of society were distinguished old-Africa hands. John thoroughly enjoyed Grahamstown where, in the partnership of Hoskins and English, he made his mark in the restoration and extension of many significant buildings. His addition to the Anglican chapel at Hog's Back is a masterpiece, as is his incorporation of the old fayade into the rebuilding and extension of the Magistrates' Court.
- Full Text:
- Date Issued: 2013
Swansea & Brecon Guild : prelude, the Bevan family, and the first and anniversary peals
- Authors: Lewis, Colin A
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6193 , http://hdl.handle.net/10962/d1013420 , http://www.ringingworld.co.uk
- Description: [From Conclusion] The Swansea & Brecon Guild owes its foundation largely to the interest of the first Bishop of the Diocese: Edward Bevan, in bells, ringers and ringing. The first peal for the Guild was rung at Talgarth by members of that tower, conducted by Louis Griffiths. The anniversary peal was also rung at Talgarth and consisted of the methods and variations that were probably rung in the original peal. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2013
- Authors: Lewis, Colin A
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6193 , http://hdl.handle.net/10962/d1013420 , http://www.ringingworld.co.uk
- Description: [From Conclusion] The Swansea & Brecon Guild owes its foundation largely to the interest of the first Bishop of the Diocese: Edward Bevan, in bells, ringers and ringing. The first peal for the Guild was rung at Talgarth by members of that tower, conducted by Louis Griffiths. The anniversary peal was also rung at Talgarth and consisted of the methods and variations that were probably rung in the original peal. , Colin Lewis was Professor of Geography at Rhodes University, Grahamstown, South Africa from 1989 until his retirement at the end of 2007. In 1990, with the strong support of the incumbent Vice-Chancellor, Dr Derek Henderson, he instigated the Certificate in Change Ringing (Church Bell Ringing) in the Rhodes University Department of Music and Musicology - the first such course to be offered in Africa. Since that date he has lectured in the basic theory, and taught the practice of change ringing. He is the Ringing Master of the Cathedral of St Michael and St George, Grahamstown, South Africa.
- Full Text:
- Date Issued: 2013
Rural racing is thriving: competing is mainly for prestige
- MacGregor, David, Paterson, Craig
- Authors: MacGregor, David , Paterson, Craig
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:7100 , http://hdl.handle.net/10962/d1006618
- Description: Commissioned by the Eastern Cape Gambling and Betting Board (ECGBB), the Status of Traditional Horse Racing in the Eastern Cape report provides a fascinating glimpse into the long-lasting and often little known connection many Xhosa people have with horses. A cornerstone of rural Xhosa life, horses have been used for generations for work and transport - as well as racing.
- Full Text:
- Date Issued: 2013
- Authors: MacGregor, David , Paterson, Craig
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:7100 , http://hdl.handle.net/10962/d1006618
- Description: Commissioned by the Eastern Cape Gambling and Betting Board (ECGBB), the Status of Traditional Horse Racing in the Eastern Cape report provides a fascinating glimpse into the long-lasting and often little known connection many Xhosa people have with horses. A cornerstone of rural Xhosa life, horses have been used for generations for work and transport - as well as racing.
- Full Text:
- Date Issued: 2013
Men and talk about legal abortion in South Africa: equality, support and rights discourses undermining reproductive ‘choice’
- Macleod, Catriona I, Hansjee, Jateen
- Authors: Macleod, Catriona I , Hansjee, Jateen
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6221 , http://hdl.handle.net/10962/d1006282 , https://www.tandfonline.com/doi/abs/10.1080/13691058.2013.802815
- Description: Discursive constructions of abortion are embedded in the social and gendered power relations of a particular socio-historical space. As part of research on public discourses concerning abortion in South Africa where there has been a radical liberalisation of abortion legislation, we collected data from male group discussions about a vignette concerning abortion, and newspaper articles written by men about abortion. Our analysis revealed how discourses of equality, support and rights may be used by men to subtly undermine women’s reproductive right to ‘choose’ an abortion. Within an Equal Partnership discourse, abortion, paired with the assumption of foetal personhood, was equated with violating an equal heterosexual partnership and a man’s patriarchal duty to protect a child. A New Man discourse, which positions men as supportive of women, was paired with the assumption of men as rational and women as irrational in decision-making, to allow for the possibility of men dissuading women from terminating a pregnancy. A Rights discourse was invoked to suggest that abortion violates men’s paternal rights.
- Full Text:
- Date Issued: 2013
- Authors: Macleod, Catriona I , Hansjee, Jateen
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6221 , http://hdl.handle.net/10962/d1006282 , https://www.tandfonline.com/doi/abs/10.1080/13691058.2013.802815
- Description: Discursive constructions of abortion are embedded in the social and gendered power relations of a particular socio-historical space. As part of research on public discourses concerning abortion in South Africa where there has been a radical liberalisation of abortion legislation, we collected data from male group discussions about a vignette concerning abortion, and newspaper articles written by men about abortion. Our analysis revealed how discourses of equality, support and rights may be used by men to subtly undermine women’s reproductive right to ‘choose’ an abortion. Within an Equal Partnership discourse, abortion, paired with the assumption of foetal personhood, was equated with violating an equal heterosexual partnership and a man’s patriarchal duty to protect a child. A New Man discourse, which positions men as supportive of women, was paired with the assumption of men as rational and women as irrational in decision-making, to allow for the possibility of men dissuading women from terminating a pregnancy. A Rights discourse was invoked to suggest that abortion violates men’s paternal rights.
- Full Text:
- Date Issued: 2013
Men and talk about legal abortion in South Africa : equality, support and rights discourses undermining reproductive ‘choice’
- Macleod, Catriona I, Hansjee, Jateen
- Authors: Macleod, Catriona I , Hansjee, Jateen
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6295 , http://hdl.handle.net/10962/d1014770 , http://www.tandfonline.com/doi/full/10.1080/13691058.2013.802815
- Description: Discursive constructions of abortion are embedded in the social and gendered power relations of a particular socio-historical space. As part of research on public discourses concerning abortion in South Africa where there has been a radical liberalisation of abortion legislation, we collected data from male group discussions about a vignette concerning abortion, and newspaper articles written by men about abortion. Our analysis revealed how discourses of equality, support and rights may be used by men to subtly undermine women's reproductive right to ‘choose’ an abortion. Within an Equal Partnership discourse, abortion, paired with the assumption of foetal personhood, was equated with violating an equal heterosexual partnership and a man's patriarchal duty to protect a child. A New Man discourse, which positions men as supportive of women, was paired with the assumption of men as rational and women as irrational in decision-making, to allow for the possibility of men dissuading women from terminating a pregnancy. A Rights discourse was invoked to suggest that abortion violates men's paternal rights.
- Full Text:
- Date Issued: 2013
- Authors: Macleod, Catriona I , Hansjee, Jateen
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6295 , http://hdl.handle.net/10962/d1014770 , http://www.tandfonline.com/doi/full/10.1080/13691058.2013.802815
- Description: Discursive constructions of abortion are embedded in the social and gendered power relations of a particular socio-historical space. As part of research on public discourses concerning abortion in South Africa where there has been a radical liberalisation of abortion legislation, we collected data from male group discussions about a vignette concerning abortion, and newspaper articles written by men about abortion. Our analysis revealed how discourses of equality, support and rights may be used by men to subtly undermine women's reproductive right to ‘choose’ an abortion. Within an Equal Partnership discourse, abortion, paired with the assumption of foetal personhood, was equated with violating an equal heterosexual partnership and a man's patriarchal duty to protect a child. A New Man discourse, which positions men as supportive of women, was paired with the assumption of men as rational and women as irrational in decision-making, to allow for the possibility of men dissuading women from terminating a pregnancy. A Rights discourse was invoked to suggest that abortion violates men's paternal rights.
- Full Text:
- Date Issued: 2013
Reflecting on South African psychology: published research, ‘relevance’ and social issues
- Macleod, Catriona I, Howell, Simon
- Authors: Macleod, Catriona I , Howell, Simon
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6219 , http://hdl.handle.net/10962/d1006277
- Description: As South Africa prepared to host the 30th International Congress of Psychology in 2012, a call was made to reflect on the strengths of and challenges facing contemporary South African Psychology. This paper presents our response to our brief to focus on social issues by presenting the results of a situational analysis of South African Psychology over the last five years and comparing this corpus of data to a similar analysis reported in Macleod (2004). Articles appearing in the South African Journal of Psychology (SAJP) and abstracts in PsycINFO with the keyword ‘South Africa’ over a 5½ year period were analysed. The content of 243 SAJP articles and 1986 PsycINFO abstracts were analysed using the codes developed by Macleod (2004). Results indicate: an increase in the number of articles, a reduction in the percentage of articles using quantitative methodologies and ‘hard’ science theoretical frameworks (particularly in the SAJP), and an increase in qualitative, theoretical, and methodological papers, and papers using systems-oriented theory (particularly in the SAJP). Traditional topics of assessment, stress and psychopathology continue to dominate, with social issues such as housing, land reform, development programmes, water resources and socio-economic inequities being largely ignored. Most research continues to be conducted in Gauteng, KwaZulu/Natal and the Western Cape, predominantly with adult, urban-based, middle-class participants, sourced mainly from universities, hospitals or clinics and schools. Collaborations or comparisons with other African, Asian, South American and Middle East countries have decreased. While the analysis presented in this paper is limited by its exclusion of books, theses, research reports and monographs, it shows that in published research there are some positive trends and some disappointments. The limited number of social issues featuring in published research, the under-representation of certain sectors of the population as participants, and the decrease in collaboration with, or comparison to, countries from the global ‘South’ represent challenges that require systematic attention.
- Full Text:
- Date Issued: 2013
- Authors: Macleod, Catriona I , Howell, Simon
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6219 , http://hdl.handle.net/10962/d1006277
- Description: As South Africa prepared to host the 30th International Congress of Psychology in 2012, a call was made to reflect on the strengths of and challenges facing contemporary South African Psychology. This paper presents our response to our brief to focus on social issues by presenting the results of a situational analysis of South African Psychology over the last five years and comparing this corpus of data to a similar analysis reported in Macleod (2004). Articles appearing in the South African Journal of Psychology (SAJP) and abstracts in PsycINFO with the keyword ‘South Africa’ over a 5½ year period were analysed. The content of 243 SAJP articles and 1986 PsycINFO abstracts were analysed using the codes developed by Macleod (2004). Results indicate: an increase in the number of articles, a reduction in the percentage of articles using quantitative methodologies and ‘hard’ science theoretical frameworks (particularly in the SAJP), and an increase in qualitative, theoretical, and methodological papers, and papers using systems-oriented theory (particularly in the SAJP). Traditional topics of assessment, stress and psychopathology continue to dominate, with social issues such as housing, land reform, development programmes, water resources and socio-economic inequities being largely ignored. Most research continues to be conducted in Gauteng, KwaZulu/Natal and the Western Cape, predominantly with adult, urban-based, middle-class participants, sourced mainly from universities, hospitals or clinics and schools. Collaborations or comparisons with other African, Asian, South American and Middle East countries have decreased. While the analysis presented in this paper is limited by its exclusion of books, theses, research reports and monographs, it shows that in published research there are some positive trends and some disappointments. The limited number of social issues featuring in published research, the under-representation of certain sectors of the population as participants, and the decrease in collaboration with, or comparison to, countries from the global ‘South’ represent challenges that require systematic attention.
- Full Text:
- Date Issued: 2013
Electrochemical impedimetric immunosensor for the detection of measles-specific IgG antibodies after measles infections
- Mashazi, Philani N, Tetyana, Phumlani, Vilakazi, Sibulelo, Nyokong, Tebello
- Authors: Mashazi, Philani N , Tetyana, Phumlani , Vilakazi, Sibulelo , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7325 , http://hdl.handle.net/10962/d1020575
- Description: The detection of measles-specific primary antibodies (IgG) using electrochemical impedimetric immunosensors is reported. The optimum conditions for electrode saturation were reached after 40 min for 1 μg ml−1 antibody concentrations. Surface roughness using AFM increased with each immobilization or antigen-antibody reaction step clearly confirming the surface modification and recognition between antigen and antibody. The human serum (HS) and new-born calf serum (NCS) spiked with antigen-specific antibody were studied to mimic the real sample analysis. The HS and NCS sera containing antibodies due to measles exhibited correlation between the increasing antibody serum concentrations and the charge-transfer resistance (electrochemically measured). This work clearly showed the potential use of impedance as the preferred electrochemical method for detecting measles-antibodies in label-free manner. , Original publication is available at http://dx.doi.org/10.1016/j.bios.2013.04.028
- Full Text: false
- Authors: Mashazi, Philani N , Tetyana, Phumlani , Vilakazi, Sibulelo , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7325 , http://hdl.handle.net/10962/d1020575
- Description: The detection of measles-specific primary antibodies (IgG) using electrochemical impedimetric immunosensors is reported. The optimum conditions for electrode saturation were reached after 40 min for 1 μg ml−1 antibody concentrations. Surface roughness using AFM increased with each immobilization or antigen-antibody reaction step clearly confirming the surface modification and recognition between antigen and antibody. The human serum (HS) and new-born calf serum (NCS) spiked with antigen-specific antibody were studied to mimic the real sample analysis. The HS and NCS sera containing antibodies due to measles exhibited correlation between the increasing antibody serum concentrations and the charge-transfer resistance (electrochemically measured). This work clearly showed the potential use of impedance as the preferred electrochemical method for detecting measles-antibodies in label-free manner. , Original publication is available at http://dx.doi.org/10.1016/j.bios.2013.04.028
- Full Text: false
Photodynamic inactivation of Staphylococcus aureus using low symmetrically substituted phthalocyanines supported on a polystyrene polymer fiber
- Masilela, Nkosiphile, Kleyi, Phumelele, Tshentu, Zenixole, Priniotakis, Georgios, Westbroek, Philippe, Nyokong, Tebello
- Authors: Masilela, Nkosiphile , Kleyi, Phumelele , Tshentu, Zenixole , Priniotakis, Georgios , Westbroek, Philippe , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7330 , http://hdl.handle.net/10962/d1020591
- Description: This work reports on the antimicrobial photo-activities of a series of low symmetrically substituted phthalocyanine complexes in solution and in a fiber matrix. Phthalocyanine complexes were successfully electrospun into a polystyrene polymer. The fiber diameter ranged from 240 nm to 390 nm in average. The modified polymer fiber showed successful singlet oxygen production with the Ge monocarboxy phthalocyanine modified fiber giving the highest singlet oxygen quantum yield value of 0.46 due to lack of aggregation when in the polymer. All the unsymmetrically substituted complexes showed antimicrobial activity towards S. Aureus under illumination with visible light. The symmetrical ZnPc and ZnTPCPc showed no activity under illumination with light in the fiber matrix due to low singlet oxygen production. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2012.10.001
- Full Text: false
- Authors: Masilela, Nkosiphile , Kleyi, Phumelele , Tshentu, Zenixole , Priniotakis, Georgios , Westbroek, Philippe , Nyokong, Tebello
- Language: English
- Type: Article
- Identifier: vital:7330 , http://hdl.handle.net/10962/d1020591
- Description: This work reports on the antimicrobial photo-activities of a series of low symmetrically substituted phthalocyanine complexes in solution and in a fiber matrix. Phthalocyanine complexes were successfully electrospun into a polystyrene polymer. The fiber diameter ranged from 240 nm to 390 nm in average. The modified polymer fiber showed successful singlet oxygen production with the Ge monocarboxy phthalocyanine modified fiber giving the highest singlet oxygen quantum yield value of 0.46 due to lack of aggregation when in the polymer. All the unsymmetrically substituted complexes showed antimicrobial activity towards S. Aureus under illumination with visible light. The symmetrical ZnPc and ZnTPCPc showed no activity under illumination with light in the fiber matrix due to low singlet oxygen production. , Original publication is available at http://dx.doi.org/10.1016/j.dyepig.2012.10.001
- Full Text: false
When veiled silences speak: reflexivity, trouble and repair as methodological tools for interpreting the unspoken in discourse-based data
- Morison, Tracy, Macleod, Catriona I
- Authors: Morison, Tracy , Macleod, Catriona I
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6220 , http://hdl.handle.net/10962/d1006280 , http://dx.doi.org/10.1177/1468794113488129
- Description: Researchers who have attempted to make sense of silence in data have generally considered literal silences or such things as laughter. We consider the analysis of veiled silences where participants speak, but their speaking serves as ‘noise’ that ‘veils’, or masks, their inability or unwillingness to talk about a (potentially sensitive) topic. Extending Lisa Mazzei’s ‘problematic of silence’ by using our performativity-performance analytical method, we propose the purposeful use of ‘unusual conversational moves’, the deployment of researcher reflexivity, and the analysis of trouble and repair as methods to expose taken-for-granted normative frameworks in veiled silences. We illustrate the potential of these research practices through reference to our study on men’s involvement in reproductive decision-making, in which participants demonstrated an inability to engage with the topic. The veiled silence that this produced, together with what was said, pointed to the operation of procreative heteronormativity.
- Full Text:
- Date Issued: 2013
- Authors: Morison, Tracy , Macleod, Catriona I
- Date: 2013
- Language: English
- Type: Article
- Identifier: vital:6220 , http://hdl.handle.net/10962/d1006280 , http://dx.doi.org/10.1177/1468794113488129
- Description: Researchers who have attempted to make sense of silence in data have generally considered literal silences or such things as laughter. We consider the analysis of veiled silences where participants speak, but their speaking serves as ‘noise’ that ‘veils’, or masks, their inability or unwillingness to talk about a (potentially sensitive) topic. Extending Lisa Mazzei’s ‘problematic of silence’ by using our performativity-performance analytical method, we propose the purposeful use of ‘unusual conversational moves’, the deployment of researcher reflexivity, and the analysis of trouble and repair as methods to expose taken-for-granted normative frameworks in veiled silences. We illustrate the potential of these research practices through reference to our study on men’s involvement in reproductive decision-making, in which participants demonstrated an inability to engage with the topic. The veiled silence that this produced, together with what was said, pointed to the operation of procreative heteronormativity.
- Full Text:
- Date Issued: 2013